GCN2 MODULATING COMPOUNDS AND USES THEREOF CROSS REFERENCE TO RELATED APPLICATION [001] This application claims priority to U.S. Provisional Application No.63/140,314 filed January 22, 2021, which is incorporated herein by reference in its entirety BACKGROUND OF THE INVENTION [002] Cancer continues to be a significant health problem despite the substantial research efforts and scientific advances reported in the literature for treating this disease. Some of the most frequently diagnosed cancers include prostate cancer, breast cancer, and lung cancer. Prostate cancer is the most common form of cancer in men. Breast cancer remains a leading cause of death in women. Current treatment options for these cancers are not effective for all patients and/or can have substantial adverse side effects. New therapies are needed to address this unmet need in cancer therapy. [003] General control nonderepressible kinase 2 (GCN2) is a serine/threonine protein kinase that phosphorylates the α subunit of eukaryotic initiation factor 2 (eIF2α) in response to amino acid deficiency (see, for example, Wek, R.C. et al. in Biochem. Soc. Trans.2006, 34(Pt 1), p.7-11). Expression and activation of GCN2 have been shown to be elevated in human and mouse tumors, and reduction in the expression of GCN2 has been shown to inhibit tumor growth (see e.g., Ye, J. et al. in EMBO J.2010, 29(12), p.2082-2096). Tumors grow in an environment of amino acid deficiency which can be further depleted with chemotherapy inducing a dependence on autophagy which requires GCN2 activity. In addition, GCN2 mediates the induction of anergy in T cells in response to tryptophan depletion by indoleamine 2,3-dioxygenase (IDO) in the tumor microenvironment (Munn, D. H. et al in Immunity 2005, 22, p.633-642) and is essential for the proliferative fitness of cytotoxic T cells in amino acid limiting environments (Van de Velde, L-A., et al. in Cell Reports 2016, 17, p.2247-2258). Inhibition of GCN2 has been reported as a therapeutic approach for cancer therapy (see, e.g., Wei, C. et al. in Mol. Biol. Cell.2015, 26(6), p.1044- 1057). Accordingly, compounds having modulatory activity towards GCN2 are needed as therapeutic agents for treating cancer, with additional applications in the treatment of neurodegenerative diseases and doxorubicin-induced cardiotoxicity. SUMMARY OF THE INVENTION [004] Provided herein are compounds and compositions for the modulation of GCN2 (e.g., the activation or inhibition of GCN2). In various embodiments, the compounds and compositions described herein are useful for the treatment of GCN2 mediated conditions, diseases, or disorders (e.g., cancers and neurodegenerative diseases). [005] In one aspect, provided herein is a compound represented by Formula (Ia) or a pharmaceutically acceptable salt thereof, wherein: C is selected from 7-10 membered bicyclic heterocyclyl, 8 membered bicyclic heteroaryl, or 9-membered bicyclic heteroaryl selected from the group consisting of , and , wherein the 7-10 membered bicyclic heterocyclyl, 8 membered bicyclic heteroaryl, or 9 membered bicyclic heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ³ ; wherein the 7-10 membered bicyclic heterocyclyl is partially unsaturated and contains at least two nitrogen atoms; wherein the 8 membered bicyclic heteroaryl contains at least two nitrogen items; wherein, if the 7-10 membered bicyclic heterocyclyl, 8 membered bicyclic heteroaryl, or 9 membered bicyclic heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; X is selected from the group consisting of CH, C(R ⁸ ) and N; R ³ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, C _1-6 alkoxyl, hydroxyl, oxo, phenyl, -C(O)N(R ^A )(R ^B ), - N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _{1- 6} alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ⁴ is selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl, -N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _{1- 6} alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _{1- 6} alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^4a ; R ⁵ is selected from the group consisting of hydrogen, halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _{1- 6} alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _{1- 6} alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^5a ; R ⁶ is selected from the group consisting of halogen, C _1-6 alkyl, cyano, C _1-6 alkoxyl, and C _3-6 cycloalkyl, wherein the C _1-6 alkyl and C _3-6 cycloalkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^6a ; R ⁷ is selected from the group consisting of fluoro, chloro, methyl, and cyano; R ⁸ is selected from is selected from the group consisting of halogen, C _1-6 alkyl, C _{3- 6} cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )- C(O)(R ^B ), -(C _1-6 alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^8a ; or when X is C(R ⁸ ), R ⁸ and R ⁵ may optionally combine together with the atoms to which they are attached to form a 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl, wherein the 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more hydroxyl substituents; wherein, if the 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^A is independently, for each occurrence, hydrogen or C _1-6 alkyl; R ^B is independently, for each occurrence, selected from the group consisting of hydrogen, C _1-6 alkyl, C _3-6 cycloalkyl, phenyl, 5-6 membered heterocyclyl, and 5-6 membered heteroaryl, wherein the C _1-6 alkyl or phenyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^e ; and wherein, if the 5-6 membered heteroaryl or 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ^3a is independently, for each occurrence, selected from the group consisting of halogen, cyano, hydroxyl, C _1-6 alkyl, phenyl, C _3-6 cycloalkyl, 5-6 membered heterocyclyl, and -CO ₂ (C _{1- 6} alkyl), wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen, hydroxyl, and phenyl; and wherein, if the 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^4a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^5a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^6a is independently, for each occurrence, halogen; R ^8a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^e is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, C _1-6 alkyl, 3-6 membered cycloalkyl, 5-6 membered heterocyclyl, -N(R ^C )(R ^D ), and - S(O) ₂ C _1-6 alkyl, wherein C _1-6 alkyl or 5-6 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from oxo and -N(R ^C )(R ^D ); and R ^C and R ^D are each independently selected from hydrogen and C _1-6 alkyl; wherein the compound of Formula (I-1) is not

. [006] In another aspect, provided herein is a compound represented by Formula (Ia) or a pharmaceutically acceptable salt thereof, wherein: C is selected from 9-membered bicyclic heterocyclyl and 8-9 membered bicyclic heteroaryl selected from the group consisting of , , and wherein the 9 membered bicyclic heterocyclyl or 8-9 membered bicyclic heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ³ ; wherein the 9 membered bicyclic heterocyclyl is partially unsaturated and contains at least two nitrogen atoms; wherein, if the 9membered bicyclic heterocyclyl or 8-9 membered bicyclic heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; X is selected from the group consisting of CH, C(R ⁸ ) and N; R ³ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, C _1-6 alkoxyl, hydroxyl, oxo, phenyl, -C(O)N(R ^A )(R ^B ), - N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _{1- 6} alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ⁴ is selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _1-6 alkylene)- N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^4a ; R ⁵ is selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _1-6 alkylene)- N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^5a ; R ⁶ is selected from the group consisting of halogen, C _1-6 alkyl, cyano, C _1-6 alkoxyl, and C _3-6 cycloalkyl, wherein the C _1-6 alkyl and C _3-6 cycloalkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^6a ; R ⁷ is selected from the group consisting of fluoro, chloro, methyl, and cyano; R ⁸ is selected from is selected from the group consisting of halogen, C _1-6 alkyl, C _{3- 6} cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )- C(O)(R ^B ), -(C _1-6 alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^8a ; or when X is C(R ⁸ ), R ⁸ and R ⁵ may optionally combine together with the atoms to which they are attached to form a 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl, wherein the 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more hydroxyl substituents; wherein, if the 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^A is independently, for each occurrence, hydrogen or C _1-6 alkyl; R ^B is independently, for each occurrence, selected from the group consisting of hydrogen, C _1-6 alkyl, C _3-6 cycloalkyl, phenyl, 5-6 membered heterocyclyl, and 5-6 membered heteroaryl, wherein the C _1-6 alkyl or phenyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^e ; and wherein, if the 5-6 membered heteroaryl or 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ^3a is independently, for each occurrence, selected from the group consisting of halogen, cyano, hydroxyl, C _1-6 alkyl, phenyl, C _3-6 cycloalkyl, 5-6 membered heterocyclyl, and -CO ₂ (C _{1- 6} alkyl), wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen, hydroxyl, and phenyl; and wherein, if the 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^4a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^5a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^6a is independently, for each occurrence, halogen; R ^8a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^e is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, C _1-6 alkyl, 3-6 membered cycloalkyl, 5-6 membered heterocyclyl, -N(R ^C )(R ^D ), and - S(O) ₂ C _1-6 alkyl, wherein C _1-6 alkyl or 5-6 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from oxo and -N(R ^C )(R ^D ); and R ^C and R ^D are each independently selected from hydrogen and C _1-6 alkyl. [007] In another aspect, provided herein is a compound represented by Formula (Ia) or a pharmaceutically acceptable salt thereof, wherein: C is selected from 9-membered bicyclic heterocyclyl and 8-9 membered bicyclic heteroaryl selected from the group consisting of wherein the 9- membered bicyclic heterocyclyl or 8-9 membered bicyclic heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ³ ; wherein the 9membered bicyclic heterocyclyl is partially unsaturated and contains at least two nitrogen atoms; wherein, if the 9membered bicyclic heterocyclyl or 8-9 membered bicyclic heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; X is selected from the group consisting of CH, C(R ⁸ ) and N; R ³ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _1-6 alkoxyl, oxo, -C(O)N(R ^A )(R ^B ), -N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _1-6 alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ⁴ is selected from the group consisting of halogen, C _1-6 alkyl, and cyano, wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^4a ; R ⁵ is selected from the group consisting of C _1-6 alkyl, cyano, hydroxyl, C _1-6 alkoxyl, and - O-C _3-6 cycloalkyl, wherein the C _1-6 alkyl and C _1-6 alkoxyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^5a ; R ⁸ is cyano; or when X is C(R ⁸ ), R ⁸ and R ⁵ may optionally combine together with the atoms to which they are attached to form a 3-7 membered carbocyclyl, wherein the 3-7 membered carbocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more hydroxyl substituents; R ⁶ is selected from the group consisting of hydrogen, halogen, C _1-6 alkyl, and cyano, wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^6a ; R ⁷ is halogen; R ^A is hydrogen; R ^B is independently, for each occurrence, selected from the group consisting of hydrogen, C _1-6 alkyl, phenyl, 5-6 membered heterocyclyl, and 5-6 membered heteroaryl, wherein the C _1-6 alkyl or phenyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^e ; and wherein, if the 5-6 membered heteroaryl or 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ^3a is independently, for each occurrence, selected from the group consisting of halogen, cyano, hydroxyl, C _1-6 alkyl, phenyl, C _3-6 cycloalkyl, 5-6 membered heterocyclyl, and -CO ₂ (C _{1- 6} alkyl), wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen, hydroxyl, and phenyl; and wherein, if the 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^4a is independently, for each occurrence, halogen; R ^5a is independently, for each occurrence, selected from halogen and phenyl; R ^6a is halogen; R ^e is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, C _1-6 alkyl, 3-6 membered cycloalkyl, 5-6 membered heterocyclyl, -N(R ^C )(R ^D ), and - S(O) ₂ C _1-6 alkyl, wherein the C _1-6 alkyl or 5-6 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from oxo and -N(R ^C )(R ^D ); and R ^C and R ^D are each independently selected from hydrogen and C _1-6 alkyl. [008] In another aspect, provided herein is a compound of selected from any compound set forth in Table 1, or a pharmaceutically acceptable salt thereof. [009] In another aspect, provided herein is a pharmaceutical composition comprising a compound of any embodiment and a pharmaceutically acceptable carrier. [010] In another aspect, provided herein is a method of treating cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of any embodiment. [011] In some embodiments, the cancer is colon cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, lung cancer, bladder cancer, stomach cancer, cervical cancer, testicular cancer, skin cancer, rectal cancer, sweat gland carcinoma, sebaceous gland carcinoma, thyroid cancer, kidney cancer, uterus cancer, esophagus cancer, liver cancer, head cancer, neck cancer, throat cancer, mouth cancer, bone cancer, chest cancer, lymph node cancer, eye cancer, mesothelioma, an acoustic neuroma, oligodendroglioma, meningioma, neuroblastoma, retinoblastoma, leukemia, lymphoma, or any combination thereof. [012] In another aspect, provided herein is a method of treating a neurodegenerative disease in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of any embodiment or a pharmaceutical composition of any embodiment. In some embodiments, the neurodegenerative disease is Alzheimer's disease, Parkinson's Disease, Huntington's Disease, amyotrophic lateral sclerosis, or spinocerebellar ataxia. [013] In another aspect, provided herein is a method of treating doxorubicin-induced cardiotoxicity in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of any embodiment or a pharmaceutical composition of any embodiment. [014] In another aspect, provided herein is a method of modulating the activity of GCN2, comprising exposing GCN2 to an effective amount of a compound of any embodiment or a pharmaceutical composition of any embodiment to modulate the activity of said GCN2. DETAILED DESCRIPTION OF THE INVENTION [015] The invention provides GCN2-interacting compounds and related compounds, pharmaceutical compositions, and their use in the treatment of medical conditions, such as cancer, neurodegenerative diseases, and doxorubicin-induced cardiotoxicity, and in modulating (inhibiting/activating) GCN2 activity. The practice of the present invention employs, unless otherwise indicated, conventional techniques of organic chemistry, pharmacology, molecular biology (including recombinant techniques), cell biology, biochemistry, and immunology. Such techniques are explained in the literature, such as in “Comprehensive Organic Synthesis” (B.M. Trost & I. Fleming, eds., 1991-1992); “Handbook of experimental immunology” (D.M. Weir & C.C. Blackwell, eds.); “Current protocols in molecular biology” (F.M. Ausubel et al., eds., 1987, and periodic updates); and “Current protocols in immunology” (J.E. Coligan et al., eds., 1991), each of which is herein incorporated by reference in its entirety. [016] Various aspects of the invention are set forth below in sections; however, aspects of the invention described in one particular section are not to be limited to any particular section. Further, when a variable is not accompanied by a definition, the previous definition of the variable controls. Definitions [017] The terms used herein have their ordinary meaning and the meaning of such terms is independent at each occurrence thereof. That notwithstanding and except where stated otherwise, the following definitions apply throughout the specification and claims. Chemical names, common names, and chemical structures may be used interchangeably to describe the same structure. If a chemical compound is referred to using both a chemical structure and a chemical name, and an ambiguity exists between the structure and the name, the structure predominates. These definitions apply regardless of whether a term is used by itself or in combination with other terms, unless otherwise indicated. Hence, the definition of “alkyl” applies to “alkyl” as well as the “alkyl” portions of “-O-alkyl” etc. [018] The term “alkyl” refers to a saturated straight or branched hydrocarbon, such as a straight or branched group of 1-12, 1-10, or 1-6 carbon atoms, referred to herein as C ₁ -C ₁₂ alkyl, C ₁ -C ₁₀ alkyl, and C ₁ -C ₆ alkyl, respectively. Exemplary alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2- methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1- pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4- methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, etc. [019] The term “alkylene” refers to a diradical of an alkyl group. Exemplary alkylene groups include –CH ₂ -, –CH ₂ CH ₂ -, and –CH ₂ C(H)(CH ₃ )CH ₂ -. The term “-(C ₀ alkylene)-“ refers to a bond. Accordingly, the term “-(C _0-3 alkylene)-” encompasses a bond (i.e., C ₀ ) and a -(C _1-3 alkylene) group. [020] As used herein, “carbocyclyl” or “carbocyclic” refers to a radical of a non–aromatic cyclic hydrocarbon group having from 3 to 10 ring carbon atoms (“C3–10 carbocyclyl”) and zero heteroatoms in the non–aromatic ring system. In certain embodiments, a carbocyclyl group has 3 to 8 ring carbon atoms. In certain embodiments, a carbocyclyl group has 3 to 7 ring carbon atoms (“C3-7 carbocycyl”). In certain embodiments, a carbocyclyl group has 3 to 6 ring carbon atoms (“C3–6 carbocyclyl”). In certain embodiments, a carbocyclyl group has 5 to 10 ring carbon atoms (“C5–10 carbocyclyl”). In certain embodiments, a carbocyclyl group has 5 to 10 ring carbon atoms (“C7–10 carbocyclyl”). Exemplary C3–6 carbocyclyl groups include, without limitation, cyclopropyl (C3),cyclobutyl (C4), cyclobutenyl (C4), cyclopentyl (C5), cyclopentenyl (C5), cyclohexyl (C6), cyclohexenyl (C6), cyclohexadienyl (C6), and the like. Exemplary C3–8 carbocyclyl groups include, without limitation, the aforementioned C3–6 carbocyclyl groups as well as cycloheptyl (C7), cycloheptenyl (C7), cycloheptadienyl (C7), cycloheptatrienyl (C7), cyclooctyl (C8), cyclooctenyl (C8), bicyclo[2.2.1]heptanyl (C7), bicyclo[2.2.2]octanyl (C8), and the like. Exemplary C3–10 carbocyclyl groups include, without limitation, the aforementioned C3–8 carbocyclyl groups as well as cyclononyl (C9), cyclononenyl (C9), cyclodecyl (C10), cyclodecenyl (C10), octahydro–1H–indenyl (C9), decahydronaphthalenyl (C10), spiro[4.5]decanyl (C10), and the like. As the foregoing examples illustrate, in certain embodiments, the carbocyclyl group is either monocyclic (“monocyclic carbocyclyl”) or contain a fused, bridged or spiro ring system such as a bicyclic system (“bicyclic carbocyclyl”) and can be saturated or partially unsaturated. [021] The term “cycloalkyl” refers to a monovalent saturated cyclic, bicyclic, or bridged cyclic (e.g., adamantyl) hydrocarbon group of 3-12, 3-8, 4-8, or 4-6 carbons, referred to herein, e.g., as “C ₃ -C ₆ cycloalkyl,” derived from a cycloalkane. Exemplary cycloalkyl groups include cyclohexyl, cyclopentyl, cyclobutyl, and cyclopropyl. The term “halocycloalkyl” refers to a cycloalkyl group that is substituted with at least one halogen. [022] The term “cycloalkylene” refers to a diradical of a cycloalkyl group. Exemplary cycloalkylene groups include and [023] The term “haloalkyl” refers to an alkyl group that is substituted with at least one halogen. Exemplary haloalkyl groups include -CH ₂ F, -CHF ₂ , -CF ₃ , -CH ₂ CF ₃ , -CF ₂ CF ₃ , and the like. [024] The term “hydroxyalkyl” refers to an alkyl group that is substituted with at least one hydroxyl. Exemplary hydroxyalkyl groups include -CH ₂ CH ₂ OH, - C(H)(OH)CH ₃ , -CH ₂ C(H)(OH)CH ₂ CH ₂ OH, and the like. [025] The term “hydroxyfluoroalkyl” refers to a hydroxyalkyl that is substituted with at least one fluoro. [026] The term “aralkyl” refers to an alkyl group substituted with an aryl group. Exemplary aralkyl groups include and [027] The term “heteroaralkyl” refers to an alkyl group substituted with a heteroaryl group. [028] The terms “alkenyl” and “alkynyl” are art-recognized and refer to unsaturated aliphatic groups analogous in length and possible substitution to the alkyls described above, but that contain at least one double or triple bond respectively. [029] The term “cycloalkenyl” refers to a monovalent unsaturated cyclic, bicyclic, or bridged (e.g., adamantyl) carbocyclic hydrocarbon containing at least one C-C double bond. In certain embodiments, the cycloalkenyl contains 5-10, 5-8, or 5-6 carbons, referred to herein, e.g., as “C ₅ -C ₆ cycloalkenyl”. Exemplary cycloalkenyl groups include cyclohexenyl and cyclopentenyl. [030] The term “aryl” is art-recognized and refers to a carbocyclic aromatic group. Representative aryl groups include phenyl, naphthyl, anthracenyl, and the like. Unless specified otherwise, the aromatic ring may be substituted at one or more ring positions with, for example, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, alkoxyl, amino, nitro, sulfhydryl, imino, amido, carboxylic acid, -C(O)alkyl, -CO ₂ alkyl, carbonyl, carboxyl, alkylthio, sulfonyl, sulfonamido, sulfonamide, ketone, aldehyde, ester, heterocyclyl, aryl or heteroaryl moieties, -CF ₃ , -CN, or the like. The term “aryl” also includes polycyclic aromatic ring systems having two or more carbocyclic rings in which two or more carbons are common to two adjoining rings (the rings are “fused rings”) wherein all of the fused rings are aromatic rings, e.g., in a naphthyl group. [031] The term “phenylene” refers to a diradical of a phenyl group. Exemplary phenylene groups include and [032] The term “heteroaryl” refers to a radical of a 5-10 membered monocyclic or bicyclic 4n+2 aromatic ring system (e.g., having 6 or 10 n electrons shared in a cyclic array) having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen and sulfur (“5-10 membered heteroaryl”). In heteroaryl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. Heteroaryl bicyclic ring systems can include one or more heteroatoms in one or both rings. “Heteroaryl” also includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more aryl groups wherein the point of attachment is either on the aryl or heteroaryl ring, and in such instances, the number of ring members designates the number of ring members in the fused (aryl/heteroaryl) ring system. Bicyclic heteroaryl groups wherein one ring does not contain a heteroatom (e.g., indolyl, quinolinyl, carbazolyl, and the like) the point of attachment can be on either ring, i.e., either the ring bearing a heteroatom (e.g., 2-indolyl) or the ring that does not contain a heteroatom (e.g., 5-indolyl). A heteroaryl group may be described as, e.g., a 6-10-membered heteroaryl, wherein the term “membered” refers to the non-hydrogen ring atoms within the moiety. [033] In some embodiments, a heteroaryl group is a 5-10 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-10 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-8 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-8 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-6 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-6 membered heteroaryl”). In some embodiments, the 5- 6 membered heteroaryl has 1-3 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heteroaryl has 1-2 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heteroaryl has 1 ring heteroatom selected from nitrogen, oxygen, and sulfur. Each instance of a heteroaryl group may be independently optionally substituted, i.e., unsubstituted (an “unsubstituted heteroaryl”) or substituted (a “substituted heteroaryl”) with one or more substituents. In certain embodiments, the heteroaryl group is unsubstituted 5-14 membered heteroaryl. In certain embodiments, the heteroaryl group is substituted 5-14 membered heteroaryl. [034] Exemplary 5-membered heteroaryl groups containing one heteroatom include, without limitation, pyrrolyl, furanyl and thiophenyl. Exemplary 5-membered heteroaryl groups containing two heteroatoms include, without limitation, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, and isothiazolyl. Exemplary 5-membered heteroaryl groups containing three heteroatoms include, without limitation, triazolyl, oxadiazolyl, and thiadiazolyl. Exemplary 5-membered heteroaryl groups containing four heteroatoms include, without limitation, tetrazolyl. Exemplary 6-membered heteroaryl groups containing one heteroatom include, without limitation, pyridinyl. Exemplary 6-membered heteroaryl groups containing two heteroatoms include, without limitation, pyridazinyl, pyrimidinyl, and pyrazinyl. Exemplary 6-membered heteroaryl groups containing three or four heteroatoms include, without limitation, triazinyl and tetrazinyl, respectively. Exemplary 7-membered heteroaryl groups containing one heteroatom include, without limitation, azepinyl, oxepinyl, and thiepinyl. Exemplary 5,6-bicyclic heteroaryl groups include, without limitation, indolyl, isoindolyl, indazolyl, benzotriazolyl, benzothiophenyl, isobenzothiophenyl, benzofuranyl, benzoisofuranyl, benzimidazolyl, benzoxazolyl, benzisoxazolyl, benzoxadiazolyl, benzthiazolyl, benzisothiazolyl, benzthiadiazolyl, indolizinyl, and purinyl. Exemplary 6,6- bicyclic heteroaryl groups include, without limitation, naphthyridinyl, pteridinyl, quinolinyl, isoquinolinyl, cinnolinyl, quinoxalinyl, phthalazinyl, and quinazolinyl. [035] The term “heteroarylene” refers to a diradical of a heteroaryl group. Exemplary heteroarylene groups include: phenylene, pyridinylene, pyridazinylene, pyrimidinylene, pyrazinylene, _. [036] The terms ortho, meta, and para are art-recognized and refer to 1,2-, 1,3- and 1,4- disubstituted benzenes, respectively. For example, the names 1,2-dimethylbenzene and ortho-dimethylbenzene are synonymous. [037] The term “heterocyclyl” or “heterocyclic” refers to a radical of a 3- to 10-membered non-aromatic ring system having ring carbon atoms and 1 to 4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, sulfur, boron, phosphorus, and silicon (“3-10 membered heterocyclyl”). In heterocyclyl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. A heterocyclyl group can either be monocyclic (“monocyclic heterocyclyl”) or a fused, bridged or spiro ring system such as a bicyclic system (“bicyclic heterocyclyl”), and can be saturated or can be partially unsaturated. Heterocyclyl bicyclic ring systems can include one or more heteroatoms in one or both rings. “Heterocyclyl” also includes ring systems wherein the heterocyclyl ring, as defined above, is fused with one or more cycloalkyl groups wherein the point of attachment is either on the cycloalkyl or heterocyclyl ring, or ring systems wherein the heterocyclyl ring, as defined above, is fused with one or more aryl or heteroaryl groups, wherein the point of attachment is on the heterocyclyl ring, and in such instances, the number of ring members continue to designate the number of ring members in the heterocyclyl ring system. A heterocyclyl group may be described as, e.g., a 3-7-membered heterocyclyl, wherein the term “membered” refers to the non-hydrogen ring atoms, i.e., carbon, nitrogen, oxygen, sulfur, boron, phosphorus, and silicon, within the moiety. Each instance of heterocyclyl may be independently optionally substituted, i.e., unsubstituted (an “unsubstituted heterocyclyl”) or substituted (a “substituted heterocyclyl”) with one or more substituents. In certain embodiments, the heterocyclyl group is unsubstituted 3-10 membered heterocyclyl. In certain embodiments, the heterocyclyl group is substituted 3-10 membered heterocyclyl. [038] In some embodiments, a heterocyclyl group is a 5-10 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, sulfur, boron, phosphorus, and silicon (“5-10 membered heterocyclyl”). In some embodiments, a heterocyclyl group is a 5-8 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-8 membered heterocyclyl”). In some embodiments, a heterocyclyl group is a 5-6 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-6 membered heterocyclyl”). In some embodiments, the 5-6 membered heterocyclyl has 1-3 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heterocyclyl has 1-2 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heterocyclyl has one ring heteroatom selected from nitrogen, oxygen, and sulfur. [039] Exemplary 3-membered heterocyclyl groups containing one heteroatom include, without limitation, azirdinyl, oxiranyl, thiorenyl. Exemplary 4-membered heterocyclyl groups containing one heteroatom include, without limitation, azetidinyl, oxetanyl and thietanyl. Exemplary 5-membered heterocyclyl groups containing one heteroatom include, without limitation, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothiophenyl, dihydrothiophenyl, pyrrolidinyl, dihydropyrrolyl and pyrrolyl-2,5-dione. Exemplary 5-membered heterocyclyl groups containing two heteroatoms include, without limitation, dioxolanyl, oxasulfuranyl, disulfuranyl, and oxazolidin-2-one. Exemplary 5-membered heterocyclyl groups containing three heteroatoms include, without limitation, triazolinyl, oxadiazolinyl, and thiadiazolinyl. Exemplary 6-membered heterocyclyl groups containing one heteroatom include, without limitation, piperidinyl, tetrahydropyranyl, dihydropyridinyl, and thianyl. Exemplary 6- membered heterocyclyl groups containing two heteroatoms include, without limitation, piperazinyl, morpholinyl, dithianyl, dioxanyl. Exemplary 6-membered heterocyclyl groups containing two heteroatoms include, without limitation, triazinanyl. Exemplary 7-membered heterocyclyl groups containing one heteroatom include, without limitation, azepanyl, oxepanyl and thiepanyl. Exemplary 8-membered heterocyclyl groups containing one heteroatom include, without limitation, azocanyl, oxecanyl and thiocanyl. Exemplary 5- membered heterocyclyl groups fused to a C6 aryl ring (also referred to herein as a 5,6- bicyclic heterocyclic ring) include, without limitation, indolinyl, isoindolinyl, dihydrobenzofuranyl, dihydrobenzothienyl, benzoxazolinonyl, and the like. Exemplary 6- membered heterocyclyl groups fused to an aryl ring (also referred to herein as a 6,6-bicyclic heterocyclic ring) include, without limitation, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and the like. [040] The term “heterocycloalkyl” refers to a saturated heterocyclyl group having, for example, 3-7 ring atoms selected from carbon and heteroatoms (e.g., O, N, or S). [041] The terms “amine” and “amino” are art-recognized and refer to both unsubstituted and substituted amines, e.g., a moiety that may be represented by the general formulas: wherein R ⁵⁰ , R ⁵¹ , R ⁵² and R ⁵³ each independently represent a hydrogen, an alkyl, an alkenyl, -(CH ₂ ) _m -R ⁶¹ , or R ⁵⁰ and R ⁵¹ , taken together with the N atom to which they are attached complete a heterocycle having from 4 to 8 atoms in the ring structure; R ⁶¹ represents an aryl, a cycloalkyl, a cycloalkenyl, a heterocycle or a polycycle; and m is zero or an integer in the range of 1 to 8. In certain embodiments, only one of R ⁵⁰ or R ⁵¹ may be a carbonyl, e.g., R ⁵⁰ , R ⁵¹ and the nitrogen together do not form an imide. In other embodiments, R ⁵⁰ and R ⁵¹ (and optionally R ⁵² ) each independently represent a hydrogen, an alkyl, an alkenyl, or - (CH ₂ ) _m -R ⁶¹ . [042] The terms “alkoxyl” or “alkoxy” are art-recognized and refer to an alkyl group, as defined above, having an oxygen radical attached thereto. Representative alkoxyl groups include methoxy, ethoxy, propyloxy, tert-butoxy and the like. An “ether” is two hydrocarbons covalently linked by an oxygen. Accordingly, the substituent of an alkyl that renders that alkyl an ether is or resembles an alkoxyl, such as may be represented by one of - O-alkyl, -O-alkenyl, -O-alkynyl, and -O-(CH ₂ ) _m -R ⁶¹ , where m and R ⁶¹ are described above. [043] The term “fluoroalkoxyl” refers to an alkoxyl group that is substituted with at least one fluoro group. Exemplary fluoroalkoxyl groups include -OCH ₂ F, -OCHF ₂ , -OCF ₃ , - OCH ₂ CF ₃ , -OCF ₂ CF ₃ , and the like. [044] The term “oxo” is art-recognized and refers to a “=O” substituent. For example, a cyclopentane substituted with an oxo group is cyclopentanone. [045] The symbols “ ”, “*”, and “**” indicate a point of attachment. [046] The term “substituted” means that one or more hydrogens on the atoms of the designated group are replaced with a selection from the indicated group, provided that the atoms’ normal valences under the existing circumstances are not exceeded, and that the substitution results in a stable compound. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds. The terms “stable compound” or “stable structure” refer to a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent. [047] When any substituent or variable occurs more than one time in any constituent or the compound of the invention, its definition on each occurrence is independent of its definition at every other occurrence, unless otherwise indicated. [048] It should also be noted that any carbon as well as heteroatom with unsatisfied valences in the text, schemes, examples and tables herein is assumed to have the sufficient number of hydrogen atom(s) to satisfy the valences. [049] One or more compounds of the invention may exist in unsolvated as well as solvated forms with pharmaceutically acceptable solvents such as water, ethanol, and the like, and it is intended that the invention embrace both solvated and unsolvated forms. “Solvate” means a physical association of a compound of this invention with one or more solvent molecules. This physical association involves varying degrees of ionic and covalent bonding, including hydrogen bonding. In certain instances, the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. “Solvate” encompasses both solution-phase and isolatable solvates. Non-limiting examples of suitable solvates include ethanolates, methanolates, and the like. “Hydrate” is a solvate wherein the solvent molecule is H ₂ O. [050] Certain compounds contained in compositions of the present invention may exist in particular geometric or stereoisomeric forms. Further, certain compounds described herein may be optically active. The present invention contemplates all such compounds, including cis- and trans-isomers, R- and S-enantiomers, diastereomers, (D)-isomers, (L)-isomers, the racemic mixtures thereof, and other mixtures thereof, as falling within the scope of the invention. The compounds may contain one or more stereogenic centers. For example, asymmetric carbon atoms may be present in a substituent such as an alkyl group. All such isomers, as well as mixtures thereof, are intended to be included in this invention, such as, for example, racemic mixtures, single enantiomers, diastereomeric mixtures and individual diastereomers. Additional asymmetric centers may be present depending upon the nature of the various substituents on the molecule. Each such asymmetric center will independently produce two optical isomers, and it is intended that all of the possible optical isomers, diastereomers in mixtures, and pure or partially purified compounds are included within the ambit of this invention. [051] Diastereomeric mixtures can be separated into their individual diastereomers on the basis of their physical chemical differences by methods known to those skilled in the art, such as, for example, by chromatography and/or fractional crystallization. Enantiomers can be separated by converting the enantiomeric mixture into a diastereomeric mixture by reaction with an appropriate optically active compound (e.g., chiral auxiliary such as a chiral alcohol or Mosher’s acid chloride), separating the diastereomers and converting (e.g., hydrolyzing) the individual diastereomers to the corresponding pure enantiomers. Alternatively, a particular enantiomer of a compound of the present invention may be prepared by asymmetric synthesis. Still further, where the molecule contains a basic functional group (such as amino) or an acidic functional group (such as carboxylic acid) diastereomeric salts are formed with an appropriate optically-active acid or base, followed by resolution of the diastereomers thus formed by fractional crystallization or chromatographic means known in the art, and subsequent recovery of the pure enantiomers. [052] Individual stereoisomers of the compounds of the invention may, for example, be substantially free of other isomers, or may be admixed, for example, as racemates or with all other, or other selected, stereoisomers. Chiral center(s) in a compound of the present invention can have the S or R configuration as defined by the IUPAC 1974 Recommendations. Further, to the extent a compound described herein may exist as an atropisomer (e.g., substituted biaryls), all forms of such atropisomer are considered part of this invention. [053] As used herein, the terms “subject” and “patient” are used interchangeable and refer to organisms to be treated by the methods of the present invention. Such organisms preferably include, but are not limited to, mammals (e.g., murines, simians, equines, bovines, porcines, canines, felines, and the like), and most preferably includes humans. [054] The term “IC ₅₀ ” is art-recognized and refers to the concentration of a compound that is required to achieve 50% inhibition of the target. [055] As used herein, the term “effective amount” refers to the amount of a compound sufficient to effect beneficial or desired results (e.g., a therapeutic, ameliorative, inhibitory or preventative result). An effective amount can be administered in one or more administrations, applications or dosages and is not intended to be limited to a particular formulation or administration route. As used herein, the term “treating” includes any effect, e.g., lessening, reducing, modulating, ameliorating or eliminating, that results in the improvement of the condition, disease, disorder, and the like, or ameliorating a symptom thereof. [056] As used herein, the term “pharmaceutical composition” refers to the combination of an active agent with a carrier, inert or active, making the composition especially suitable for diagnostic or therapeutic use in vivo or ex vivo. [057] As used herein, the term “pharmaceutically acceptable carrier” refers to any of the standard pharmaceutical carriers, such as a phosphate buffered saline solution, water, emulsions (e.g., such as an oil/water or water/oil emulsions), and various types of wetting agents. The compositions also can include stabilizers and preservatives. For examples of carriers, stabilizers and adjuvants, see e.g., Martin, Remington’s Pharmaceutical Sciences, 15th Ed., Mack Publ. Co., Easton, PA [1975]. [058] As used herein, the term “pharmaceutically acceptable salt” refers to any pharmaceutically acceptable salt (e.g., acid or base) of a compound of the present invention which, upon administration to a subject, is capable of providing a compound of this invention or an active metabolite or residue thereof. As is known to those of skill in the art, “salts” of the compounds of the present invention may be derived from inorganic or organic acids and bases. Examples of acids include, but are not limited to, hydrochloric, hydrobromic, sulfuric, nitric, perchloric, fumaric, maleic, phosphoric, glycolic, lactic, salicylic, succinic, toluene-p- sulfonic, tartaric, acetic, citric, methanesulfonic, ethanesulfonic, formic, benzoic, malonic, naphthalene-2-sulfonic, benzenesulfonic acid, and the like. Other acids, such as oxalic, while not in themselves pharmaceutically acceptable, may be employed in the preparation of salts useful as intermediates in obtaining the compounds of the invention and their pharmaceutically acceptable acid addition salts. [059] Examples of bases include, but are not limited to, alkali metals (e.g., sodium) hydroxides, alkaline earth metals (e.g., magnesium), hydroxides, ammonia, and compounds of formula NW ₃ , wherein W is C _1-4 alkyl, and the like. [060] Examples of salts include, but are not limited to: acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, flucoheptanoate, glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 2- naphthalenesulfonate, nicotinate, oxalate, palmoate, pectinate, persulfate, phenylpropionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, tosylate (also known as toluenesulfonate), undecanoate, and the like. Other examples of salts include anions of the compounds of the present invention compounded with a suitable cation such as Na ⁺ , NH ₄ ⁺ , and NW ₄ ⁺ (wherein W is a C _1-4 alkyl group), and the like. Further examples of salts include, but are not limited to, ascorbate, borate, nitrate, phosphate, salicylate, and sulfate. Further, acids which are generally considered suitable for the formation of pharmaceutically useful salts from basic pharmaceutical compounds are discussed, for example, by P. Stahl et al., Camille G. (eds.) Handbook of Pharmaceutical Salts. Properties, Selection and Use. (2002) Zurich: Wiley-VCH; S. Berge et al., Journal of Pharmaceutical Sciences (1977) 66(1) 1-19; P. Gould, International J. of Pharmaceutics (1986) 33201-217; Anderson et al., The Practice of Medicinal Chemistry (1996), Academic Press, New York; and in The Orange Book (Food & Drug Administration, Washington, D.C. on their website). These disclosures are incorporated herein by reference. [061] Additional exemplary basic salts include, but are not limited to, ammonium salts, alkali metal salts such as sodium, lithium, and potassium salts, alkaline earth metal salts such as calcium and magnesium salts, salts with organic bases (for example, organic amines) such as dicyclohexylamines, t-butyl amines, and salts with amino acids such as arginine, lysine and the like. Basic nitrogen-containing groups may be quarternized with agents such as lower alkyl halides (e.g., methyl, ethyl, and butyl chlorides, bromides and iodides), dialkyl sulfates (e.g., dimethyl, diethyl, and dibutyl sulfates), long chain halides (e.g., decyl, lauryl, and stearyl chlorides, bromides and iodides), aralkyl halides (e.g., benzyl and phenethyl bromides), and others. [062] For therapeutic use, salts of the compounds of the present invention are contemplated as being pharmaceutically acceptable. However, salts of acids and bases that are non- pharmaceutically acceptable may also find use, for example, in the preparation or purification of a pharmaceutically acceptable compound. [063] In addition, when a compound of the invention contains both a basic moiety (such as, but not limited to, a pyridine or imidazole) and an acidic moiety (such as, but not limited to, a carboxylic acid) zwitterions (“inner salts”) may be formed. Such acidic and basic salts used within the scope of the invention are pharmaceutically acceptable (i.e., non-toxic, physiologically acceptable) salts. Such salts of the compounds of the invention may be formed, for example, by reacting a compound of the invention with an amount of acid or base, such as an equivalent amount, in a medium such as one in which the salt precipitates or in an aqueous medium followed by lyophilization. [064] The present invention includes the compounds of the invention in all their isolated forms (such as any solvates, hydrates, stereoisomers, and tautomers thereof). Further, the invention includes compounds in which one or more of the atoms may be artificially enriched in a particular isotope having the same atomic number, but an atomic mass or mass number different from the atomic mass or mass number predominantly found in nature. The present invention is meant to include all suitable isotopic variations of the compounds of the invention. For example, different isotopic forms of hydrogen (H) include protium ( ¹ H) and deuterium ( ² H). Protium is the predominant hydrogen isotope found in nature. Enriching for deuterium may afford certain therapeutic advantages, such as increasing in vivo half-life or reducing dosage requirements, or may provide a compound useful as a standard for characterization of biological samples. Isotopically-enriched compounds can be prepared without undue experimentation by conventional techniques known to those skilled in the art or by processes analogous to those described in the Schemes and Examples herein using appropriate isotopically-enriched reagents and/or intermediates. [065] Throughout the description, where compositions are described as having, including, or comprising specific components, or where processes and methods are described as having, including, or comprising specific steps, it is contemplated that, additionally, there are compositions of the present invention that consist essentially of, or consist of, the recited components, and that there are processes and methods according to the present invention that consist essentially of, or consist of, the recited processing steps. [066] The terms “a” and “an” as used herein mean “one or more” and include the plural unless the context is inappropriate. [067] As a general matter, compositions specifying a percentage are by weight unless otherwise specified. Compounds [068] In one aspect, provided herein are compounds represented by Formula (I): or a pharmaceutically acceptable salt thereof, wherein: A is selected from the group consisting of phenyl, 5-6 membered heteroaryl, 7-10 membered carbocyclyl, and 5-6 membered heterocyclyl, wherein the phenyl, 5-6 membered heteroaryl, 7-10 membered carbocyclyl, or 5-6 membered heterocyclyl is substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ¹ ; B is phenylene or 5-6 membered heteroarylene, wherein the phenylene or the 5-6 membered heteroarylene may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ² ; C is selected from the group consisting of 7-10 membered bicyclic heterocyclyl, 5-8 membered heteroaryl, 8 membered bicyclic heteroaryl, and 9 membered bicyclic heteroaryl selected from the group consisting of , wherein the 7-10 membered bicyclic heterocyclyl, 5-8 membered heteroaryl, 8 membered bicyclic heteroaryl, or 9 membered bicyclic heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ³ ; and wherein, if the 7- 10 membered heterocyclyl, 5-8 membered heteroaryl, or 9 membered bicyclic heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ¹ is independently, for each occurrence, selected from the group consisting of hydrogen, halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _{3- 6} cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _1-6 alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _{1- 6} alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^1a ; R ² is independently, for each occurrence, selected from the group consisting of halogen, methyl, cyano C _1-6 alkyl, cyano, C _1-6 alkoxyl, and C _3-6 cycloalkyl, wherein the C _1-6 alkyl and C _{3- 6} cycloalkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^2a ; R ³ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, C _1-6 alkoxyl, hydroxyl, oxo, phenyl, -C(O)N(R ^A )(R ^B ), - N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _{1- 6} alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ^A is independently, for each occurrence, hydrogen or C _1-6 alkyl; R ^B is independently, for each occurrence, selected from the group consisting of hydrogen, C _1-6 alkyl, C _3-6 cycloalkyl, phenyl, 5-6 membered heterocyclyl, and 5-6 membered heteroaryl, wherein the C _1-6 alkyl or phenyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^e ; and wherein, if the 5-6 membered heteroaryl or 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ^1a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^2a is independently, for each occurrence, halogen; R ^3a is independently, for each occurrence, selected from the group consisting of halogen, cyano, hydroxyl, C _1-6 alkyl, phenyl, C _3-6 cycloalkyl, 5-6 membered heterocyclyl, and -CO ₂ (C _{1- 6} alkyl), wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen, hydroxyl, and phenyl; and wherein, if the 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^e is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, C _1-6 alkyl, 3-6 membered cycloalkyl, 5-6 membered heterocyclyl, -N(R ^C )(R ^D ) and - S(O) ₂ C _1-6 alkyl, wherein C _1-6 alkyl or 5-6 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from oxo and -N(R ^C )(R ^D ); and R ^C and R ^D are each independently selected from hydrogen and C _1-6 alkyl. [069] In another aspect, provided herein are compounds represented by Formula (Ia): or a pharmaceutically acceptable salt thereof, wherein: A is selected from the group consisting of phenyl, 5-6 membered heteroaryl, 7-10 membered carbocyclyl, and 5-6 membered heterocyclyl, wherein the phenyl, 5-6 membered heteroaryl, 7-10 membered carbocyclyl, or 5-6 membered heterocyclyl is substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ¹ ; B is phenylene or 5-6 membered heteroarylene, wherein the phenylene or 5-6 membered heteroarylene may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ² ; C is selected from the group consisting of 7-10 membered heterocyclyl, 5-8 membered heteroaryl, 9 membered bicyclic heterocyclyl, or 8-9 membered bicyclic heteroaryl selected from the group consisting of wherein the 7-10 membered heterocyclyl, 5-8 membered heteroaryl, 9 membered bicyclic heterocyclyl, or 8-9 membered bicyclic heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ³ ; and wherein, if the 7-10 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ¹ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, and -O-C _3-6 cycloalkyl, ,- N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _1-6 alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S- (C _1-6 alkyl), wherein the C _1-6 alkyl or C _1-6 alkoxyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^1a ; R ² is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, and cyano; R ³ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _1-6 alkoxyl, oxo, -C(O)N(R ^A )(R ^B ), -N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _1-6 alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^A is independently, for each occurrence, hydrogen or C _1-6 alkyl; R ^B is independently, for each occurrence, selected from the group consisting of hydrogen, C _1-6 alkyl, phenyl, 5-6 membered heterocyclyl, and 5-6 membered heteroaryl, wherein the C _1-6 alkyl or phenyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^e ; and wherein, if the 5-6 membered heteroaryl or 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ^1a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^3a is independently, for each occurrence, selected from the group consisting of halogen, cyano, hydroxyl, C _1-6 alkyl, phenyl, C _3-6 cycloalkyl, 5-6 membered heterocyclyl, and -CO ₂ (C _{1- 6} alkyl), wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen, hydroxyl, and phenyl; and wherein, if the 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^e is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, C _1-6 alkyl, 3-6 membered cycloalkyl, 5-6 membered heterocyclyl, -N(R ^C )(R ^D ), and - S(O) ₂ C _1-6 alkyl, wherein C _1-6 alkyl or 5-6 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from oxo and -N(R ^C )(R ^D ); and R ^C and R ^D are each independently C _1-6 alkyl. [070] In some embodiments, A is selected from the group consisting of phenyl, pyridyl, and _{, wherein A is substituted with one or two independent} R ¹ substituents selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, and -O-C _3-6 cycloalkyl, wherein the C _1-6 alkyl or C _{1- 6} alkoxyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen or phenyl. [071] In some embodiments, A is selected from the group consisting of phenyl, and , wherein A is substituted with two independent R ¹ substituents selected from the group consisting of halogen, C _{1- 6} alkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, and -O-C _3-6 cycloalkyl, wherein the C _1-6 alkyl or C _{1- 6} alkoxyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen or phenyl. [072] In some embodiments, R ¹ is independently, for each occurrence, selected from the group consisting of chloro, fluoro, cyano, hydroxyl, oxo, CH ₃ , CF ₃ , -O-CH ₃ , -O-CH ₂ CH ₃ , -O- CH(CH ₃ ) ₂ , -O-CH ₂ CH(CH ₃ ) ₂ , -O-CH ₂ CF ₃ , , and

[074] In some embodiments, B is phenylene or pyridylene, wherein B may be optionally substituted with one or two independent R ² substituents selected from the group consisting of halogen, C _1-6 alkyl, and cyano. [075] In some embodiments, B is wherein * denotes the point of attachment to and ** denotes the point of attachment to wherein B may be optionally substituted with one or two independent R ² substituents selected from the group consisting of halogen, C _{1- 6} alkyl, and cyano. [076] In some embodiments, B is wherein B is substituted with one R ² substituent selected from the group consisting of halogen, C _1-6 alkyl, and cyano. [077] In some embodiments, R ² is fluoro. [078] In some embodiments, B is [079] In some embodiments, B is wherein B is substituted with two independent R ² substituents selected from the group consisting of halogen, C _1-6 alkyl, and cyano. [080] In some embodiments, R ² is independently, for each occurrence, selected from the group consisting of chloro, fluoro, cyano, and CH ₃ . [081] In some embodiments, B is selected from the group consisting of [082] In another aspect, provided herein are compounds represented by Formula (Ia): or a pharmaceutically acceptable salt thereof, wherein: C is selected from 7-10 membered bicyclic heterocyclyl, 8 membered bicyclic heteroaryl, or 9-membered bicyclic heteroaryl selected from the group consisting of and , wherein the 7-10 membered bicyclic heterocyclyl, 8 membered bicyclic heteroaryl, or 9 membered bicyclic heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ³ ; wherein the 7-10 membered bicyclic heterocyclyl is partially unsaturated and contains at least two nitrogen atoms; wherein the 8 membered bicyclic heteroaryl contains at least two nitrogen items; wherein, if the 7-10 membered bicyclic heterocyclyl, 8 membered bicyclic heteroaryl, or 9 membered bicyclic heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; X is selected from the group consisting of CH, C(R ⁸ ), and N; R ³ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, C _1-6 alkoxyl, hydroxyl, oxo, phenyl, -C(O)N(R ^A )(R ^B ), - N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _{1- 6} alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ⁴ is selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl, -N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _{1- 6} alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _{1- 6} alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^4a ; R ⁵ is selected from the group consisting of hydrogen, halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _{1- 6} alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _{1- 6} alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^5a ; R ⁶ is selected from the group consisting of halogen, C _1-6 alkyl, cyano, C _1-6 alkoxyl, and C _3-6 cycloalkyl, wherein the C _1-6 alkyl and C _3-6 cycloalkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^6a ; R ⁷ is selected from the group consisting of fluoro, chloro, methyl, and cyano; R ⁸ is selected from is selected from the group consisting of halogen, C _1-6 alkyl, C _{3- 6} cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )- C(O)(R ^B ), -(C _1-6 alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^8a ; or when X is C(R ⁸ ), R ⁸ and R ⁵ may optionally combine together with the atoms to which they are attached to form a 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl, wherein the 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more hydroxyl substituents; wherein, if the 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^A is hydrogen or C _1-6 alkyl; R ^B is selected from the group consisting of hydrogen, C _1-6 alkyl, C _3-6 cycloalkyl, phenyl, 5-6 membered heterocyclyl, and 5-6 membered heteroaryl, wherein the C _1-6 alkyl or phenyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^e ; and wherein, if the 5-6 membered heteroaryl or 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^3a is independently, for each occurrence, selected from the group consisting of halogen, cyano, hydroxyl, C _1-6 alkyl, phenyl, C _3-6 cycloalkyl, 5-6 membered heterocyclyl, and -CO ₂ (C _{1- 6} alkyl), wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen, hydroxyl, and phenyl; and wherein, if the 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^4a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^5a is , for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^6a is independently, for each occurrence, halogen; R ^8a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^e is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, C _1-6 alkyl, 3-6 membered cycloalkyl, 5-6 membered heterocyclyl, -N(R ^C )(R ^D ), and - S(O) ₂ C _1-6 alkyl, wherein C _1-6 alkyl or 5-6 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from oxo and -N(R ^C )(R ^D ); and R ^C and R ^D are each independently selected from hydrogen and C _1-6 alkyl; wherein the compound of Formula (Ib) is not . [083] In another aspect, provided herein are compounds represented by Formula (Ia): or a pharmaceutically acceptable salt thereof, wherein: C is selected from 9-membered bicyclic heterocyclyl and 8-9 membered bicyclic heteroaryl selected from the group consisting of wherein the 9 membered bicyclic heterocyclyl or 8-9 membered bicyclic heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ³ ; wherein the 9 membered bicyclic heterocyclyl is partially unsaturated and contains at least two nitrogen atoms; wherein, if the 9membered bicyclic heterocyclyl or 8-9 membered bicyclic heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; X is selected from the group consisting of CH, C(R ⁸ ) and N; R ³ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, C _1-6 alkoxyl, hydroxyl, oxo, phenyl, -C(O)N(R ^A )(R ^B ), - N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _{1- 6} alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ⁴ is selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _1-6 alkylene)- N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^4a ; R ⁵ is selected from the group consisting of halogen, C _1-6 alkyl, C _3-6 cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _1-6 alkylene)- N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^5a ; R ⁶ is selected from the group consisting of halogen, C _1-6 alkyl, cyano, C _1-6 alkoxyl, and C _{3- 6} cycloalkyl, wherein the C _1-6 alkyl and C _3-6 cycloalkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^6a ; R ⁷ is selected from the group consisting of fluoro, chloro, methyl, and cyano; R ⁸ is selected from is selected from the group consisting of halogen, C _1-6 alkyl, C _{3- 6} cycloalkyl, cyano, hydroxyl, oxo, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl,-N(R ^A )(R ^B ), -N(R ^A )- C(O)(R ^B ), -(C _1-6 alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _1-6 alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^8a ; or when X is C(R ⁸ ), R ⁸ and R ⁵ may optionally combine together with the atoms to which they are attached to form a 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl, wherein the 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more hydroxyl substituents; wherein, if the 3-7 membered carbocyclyl, 3-7 membered heterocyclyl, or 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^A is hydrogen or C _1-6 alkyl; R ^B is selected from the group consisting of hydrogen, C _1-6 alkyl, C _3-6 cycloalkyl, phenyl, 5-6 membered heterocyclyl, and 5-6 membered heteroaryl, wherein the C _1-6 alkyl or phenyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^e ; and wherein, if the 5-6 membered heteroaryl or 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^3a is independently, for each occurrence, selected from the group consisting of halogen, cyano, hydroxyl, C _1-6 alkyl, phenyl, C _3-6 cycloalkyl, 5-6 membered heterocyclyl, and -CO ₂ (C _{1- 6} alkyl), wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen, hydroxyl, and phenyl; and wherein, if the 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^4a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^5a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^6a is independently, for each occurrence, halogen; R ^8a is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, and phenyl; R ^e is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, C _1-6 alkyl, 3-6 membered cycloalkyl, 5-6 membered heterocyclyl, -N(R ^C )(R ^D ), and - S(O) ₂ C _1-6 alkyl, wherein C _1-6 alkyl or 5-6 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from oxo and -N(R ^C )(R ^D ); and R ^C and R ^D are each independently selected from hydrogen and C _1-6 alkyl. [084] In another aspect, provided herein are compounds represented by Formula (Ia): or a pharmaceutically acceptable salt thereof, wherein: C is selected from 9-membered bicyclic heterocyclyl and 8-9 membered bicyclic heteroaryl selected from the group consisting of wherein the 9- membered bicyclic heterocyclyl or 8-9 membered bicyclic heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ³ ; wherein the 9membered bicyclic heterocyclyl is partially unsaturated and contains at least two nitrogen atoms; wherein, if the 9membered bicyclic heterocyclyl or 8-9 membered bicyclic heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; X is selected from the group consisting of CH, C(R ⁸ ) and N; R ³ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _1-6 alkoxyl, oxo, -C(O)N(R ^A )(R ^B ), -N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _1-6 alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ⁴ is selected from the group consisting of halogen, C _1-6 alkyl, and cyano, wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^4a ; R ⁵ is selected from the group consisting of C _1-6 alkyl, cyano, hydroxyl, C _1-6 alkoxyl, and - O-C _3-6 cycloalkyl, wherein the C _1-6 alkyl and C _1-6 alkoxyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^5a ; R ⁸ is cyano; or when X is C(R ⁸ ), R ⁸ and R ⁵ may optionally combine together with the atoms to which they are attached to form a 3-7 membered carbocyclyl, wherein the 3-7 membered carbocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more hydroxyl substituents; R ⁶ is selected from the group consisting of hydrogen, halogen, C _1-6 alkyl, and cyano, wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^6a ; R ⁷ is halogen; R ^A is hydrogen; R ^B is selected from the group consisting of hydrogen, C _1-6 alkyl, phenyl, 5-6 membered heterocyclyl, and 5-6 membered heteroaryl, wherein the C _1-6 alkyl or phenyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^e ; and wherein, if the 5-6 membered heteroaryl or 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^3a is independently, for each occurrence, selected from the group consisting of halogen, cyano, hydroxyl, C _1-6 alkyl, phenyl, C _3-6 cycloalkyl, 5-6 membered heterocyclyl, and -CO ₂ (C _{1- 6} alkyl), wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from halogen, hydroxyl, and phenyl; and wherein, if the 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ^4a is independently, for each occurrence, halogen; R ^5a is independently, for each occurrence, selected from halogen and phenyl; R ^6a is halogen; R ^e is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, C _1-6 alkyl, 3-6 membered cycloalkyl, 5-6 membered heterocyclyl, -N(R ^C )(R ^D ), and - S(O) ₂ C _1-6 alkyl, wherein the C _1-6 alkyl or 5-6 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from oxo and -N(R ^C )(R ^D ); and R ^C and R ^D are each independently selected from hydrogen and C _1-6 alkyl. [085] In some embodiments, R ⁴ is independently selected from the group consisting of chloro, fluoro, cyano, hydroxyl, oxo, CH ₃ , CF ₃ , -O-CH ₃ , -O-CH ₂ CH ₃ , -O-CH(CH ₃ ) ₂ , -O- CH ₂ CH(CH ₃ ) _2, -O-CH ₂ CF _3, In some embodiments, R ⁴ is selected from the group consisting of chloro, fluoro, cyano, and CF ₃ . [086] In some embodiments, R ⁵ is selected from the group consisting of chloro, fluoro, cyano, hydroxyl, oxo, CH ₃ , CF ₃ , -O-CH ₃ , -O-CH ₂ CH ₃ , -O-CH(CH ₃ ) ₂ , -O-CH ₂ CH(CH ₃ ) ₂ , -O- CH ₂ CF _3, In some embodiments, R ⁵ is selected from the group consisting of CH ₃ , -O-CH ₃ , -O-CH ₂ -CH ₃ , -O-CH ₂ -CF ₃ , -O-CH ₂ - C(H)(CH ₃ ) ₂ , -O-CH-(CH ₃ ) ₂ , [087] In some embodiments, X is N. [088] In some embodiments, X is (R ⁸ ). [089] In some embodiments, R ⁸ and R ⁵ are taken together with the atoms to which they are attached to form a 3-7 membered carbocyclyl, wherein the 3-7 membered carbocyclyl may be optionally substituted with hydroxyl. In some embodiments, R ⁸ and R ⁵ are taken together with the atoms to which they are attached to form a 3-7 membered carbocyclyl, wherein the 3-7 membered carbocyclyl is substituted with hydroxyl. In some embodiments, R ⁸ and R ⁵ are taken together with the atoms to which they are attached to form a 5 membered carbocyclyl, wherein the 5 membered carbocyclyl may be optionally substituted with hydroxyl. In some embodiments, R ⁸ and R ⁵ are taken together with the atoms to which they are attached to form a 5 membered carbocyclyl, wherein the 5 membered carbocyclyl is substituted with hydroxyl. [090] In some embodiments, R ⁶ is selected from the group consisting of halogen, C _1-6 alkyl, and cyano. In some embodiments, R ⁶ is selected from the group consisting of hydrogen, chloro, fluoro, cyano, and CH ₃ . In some embodiments, R ⁶ is fluoro. [091] In some embodiments, R ⁷ is fluoro or chloro. In some embodiments, R ⁷ is fluoro. [092] In some embodiments, R ⁶ is methyl, and R ⁷ is fluoro. In some embodiments, R ⁶ is fluoro, and R ⁷ is fluoro. In some embodiments, R ⁶ is chloro, and R ⁷ is fluoro. In some embodiments, R ⁶ is fluoro, and R ⁷ is chloro. In some embodiments, R ⁶ is cyano, and R ⁷ is fluoro. In some embodiments, R ⁶ is methyl, and R ⁷ is fluoro. [093] In another aspect, provided herein are compounds represented by Formula (Ib): or a pharmaceutically acceptable salt thereof, wherein: C is 7-10 membered bicyclic heterocyclyl, 5-8 membered bicyclic heteroaryl, or 9 membered bicyclic heteroaryl selected from the group consisting of wherein the 7-10 membered bicyclic heterocyclyl, 5-8 membered bicyclic heteroaryl, or 9 membered bicyclic heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ³ ; and wherein, if the 7-10 bicyclic membered heterocyclyl is partially unsaturated and contains at least two nitrogen atoms; wherein the 8 membered bicyclic heteroaryl contains at least two nitrogen items; wherein, if the 7-10 membered bicyclic heterocyclyl, 8 membered bicyclic heteroaryl, or 9 membered bicyclic heteroaryl, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl; R ³ is independently, for each occurrence, selected from the group consisting of halogen, C _1-6 alkyl, C _1-6 alkoxyl, cyano, C _1-6 alkoxyl, hydroxyl, phenyl, oxo, -C(O)N(R ^A )(R ^B ), - N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _{1- 6} alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ^A is independently, for each occurrence, hydrogen or C _1-6 alkyl; R ^B is independently, for each occurrence, selected from the group consisting of hydrogen, C _1-6 alkyl, C _3-6 cycloalkyl, phenyl, 5-6 membered heterocyclyl, and 5-6 membered heteroaryl, wherein the C _1-6 alkyl or phenyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^e ; and wherein, if the 5-6 membered heteroaryl or 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ^3a is independently, for each occurrence, selected from the group consisting of halogen, cyano, hydroxyl, C _1-6 alkyl, phenyl, C _3-6 cycloalkyl, 5-6 membered heterocyclyl, and -CO ₂ (C _{1- 6} alkyl), wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from group consisting of halogen, hydroxyl, and phenyl; and wherein, if the 5-6 membered heterocyclyl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _{1- 6} alkyl; R ^e is independently, for each occurrence, selected from the group consisting of halogen, hydroxyl, C _1-6 alkyl, 3-6 membered cycloalkyl, 5-6 membered heterocyclyl, -N(R ^C )(R ^D ), and - S(O) ₂ C _1-6 alkyl, wherein C _1-6 alkyl or 5-6 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from oxo and -N(R ^C )(R ^D ); R ^C and R ^D are each independently C _1-6 alkyl; R ⁴ is selected from the group consisting of halogen, cyano, and C _1-6 alkyl, wherein the C _1-6 alkyl may be optionally substituted on one or more available carbons by one, two, three, or more independent halogen substituents; R ⁵ is selected from the group consisting of C _1-6 alkyl, C _1-6 alkoxyl, -O-C _3-6 cycloalkyl, , C _{3- 6} cycloalkyl, cyano, hydroxyl, oxo, -N(R ^A )(R ^B ), -N(R ^A )-C(O)(R ^B ), -(C _1-6 alkylene)-N(R ^A )(R ^B ), -CO ₂ H, -CO ₂ (C _1-6 alkyl), and -S-(C _1-6 alkyl), wherein the C _1-6 alkyl, C _1-6 alkoxyl, and -S-(C _{1- 6} alkyl) may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from hydroxyl, halogen and phenyl; R ⁶ is selected from the group consisting of hydrogen, halogen, cyano, C _1-6 alkyl, C _{1- 6} alkoxyl, and C _3-6 cycloalkyl, wherein the C _1-6 alkyl and C _3-6 cycloalkyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^6a ; R ^6a is halogen; and R ⁷ is selected from the group consisting of fluoro, chloro, methyl, and cyano. [094] In some embodiments, R ⁴ is selected from the group consisting of chloro, fluoro, cyano, and CF ₃ . [095] In some embodiments, R ⁵ is selected from the group consisting of CH ₃ , -O-CH ₃ , -O- CH ₂ -CH ₃ , -O-CH ₂ -CF ₃ , -O-CH ₂ -C(H)(CH ₃ ) ₂ , -O-CH-(CH ₃ ) ₂ , and [096] In some embodiments, R ⁶ is selected from the group consisting of hydrogen, chloro, fluoro, cyano, C _1-6 alkyl, and CH ₃ . [097] In some embodiments, R ⁷ is fluoro or chloro. [098] In some embodiments, C is selected from the group consisting of , , _, , and wherein C may be optionally substituted on one or more available carbons by one, two, three, or more independent R ³ substituents selected from the group consisting of halogen, C _1-6 alkyl, C _1-6 alkoxyl, oxo, -C(O)N(R ^A )(R ^B ), -N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _1-6 alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl. [099] In some embodiments, C is selected from the group consisting of wherein C may be optionally substituted on one or more available carbons by one, two, three, or more independent R ³ substituents selected from the group consisting of halogen, C _1-6 alkyl, C _1-6 alkoxyl, oxo, - C(O)N(R ^A )(R ^B ), -N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _1-6 alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl. [0100] In some embodiments, C is selected from the group consisting of

, wherein C is substituted with one R ³ substituent selected from the group consisting of halogen, C _1-6 alkyl, C _1-6 alkoxyl, oxo, -C(O)N(R ^A )(R ^B ), -N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _1-6 alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl. [0101] In some embodiments, R ³ is selected from the group consisting of C _1-6 alkyl, - C(O)N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _1-6 alkyl and 5-10 membered heteroaryl may be optionally substituted on one or more available carbons by one, two, three, or more substituents, for each occurrence, independently selected from the group consisting of chloro, cyano, hydroxyl, CH ₃ , CF ₃ , -CH ₂ CH(CH ₃ ) ₂ , - CH ₂ OH, -C(O)OCH ₃ , cyclopropyl, phenyl, and [0102] In some embodiments, R ^A is hydrogen. [0103] In some embodiments, R ^B is hydrogen, CH ₃ , -CH ₂ CH ₃ , -CH(CH ₃ ) ₂ , -CH ₂ CH(CH ₃ ) ₂ , - CH ₂ CF ₃ , CH ₂ CH ₂ OH, -CH ₂ CH ₂ N(CH ₃ ) ₂ , -(CH ₂ ) ₃ N(CH ₃ ) ₂ , -CH ₂ CH ₂ S(O) ₂ CH ₃ , [0104] In some embodiments, R ³ is selected from the group consisting of -CH ₂ OH,

[0105] In some embodiments, C is selected from the group consisting of . [0106] In some embodiments, C is selected from the group consisting of wherein C is substituted with two independent R ³ substituents selected from the group consisting of halogen, C _1-6 alkyl, C _1-6 alkoxyl, oxo, -C(O)N(R ^A )(R ^B ), -N(R ^A )(R ^B ), 5-10 membered heterocyclyl, and 5-10 membered heteroaryl, wherein the C _1-6 alkyl, 5-10 membered heteroaryl, or 5-10 membered heterocyclyl may be optionally substituted on one or more available carbons by one, two, three, or more substituents each independently selected from R ^3a ; and wherein, if the 5-10 membered heteroaryl contains a substitutable ring nitrogen atom, that ring nitrogen atom may be optionally substituted by C _1-6 alkyl. [0107] In some embodiments, R ³ is independently, for each occurrence, selected from the group consisting of halogen, oxo, C _1-6 alkyl, C _1-6 alkoxyl, -C(O)N(R ^A )(R ^B ), -N(R ^A )(R ^B ), and 5-10 membered heteroaryl, wherein the 5-10 membered heteroaryl may be optionally substituted with chloro. [0108] In some embodiments, R ^A is hydrogen. [0109] In some embodiments, R ^B is CH ₃ . [0110] In some embodiments, R ³ is selected from the group consisting of fluoro, oxo, CH ₃ , - O-CH ₃ , -NHCH ₃ , [0111] In some embodiments, C is selected from the group consisting of _{, ,} ,

[0112] In another aspect, the compound is selected from any compound set forth in Table 1, or a pharmaceutically acceptable salt thereof. [0113] In certain embodiments, the compound is selected from the group consisting of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide; 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 6-[3-(5-chloro-2-methoxypyridine- 3-sulfonamido)-2,6-difluorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; 2-[3-(5-Chloro-2-methoxypyridine- 3-sulfonamido)-2,6-difluorophenyl]-N-methylimidazo [1,5-b]pyridazine-5-carboxamide; 2-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6-difluorop henyl]-N-methylimidazo[1,5- b]pyridazine-5-carboxamide; 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido)p henyl]-N-methylimidazo[1,5- a]pyridine-1-carboxamide; 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3-sulfonamido) phenyl]-N-methylimidazo[1,5- a]pyridine-1-carboxamide; 6-[3-(5-cyano-2-methoxypyridine-3-sulfonamido)-2,6-difluorop henyl]-N-methylimidazo[1,5- a]pyridine-1-carboxamide; 6-[3-(5-cyano-2-methylpyridine-3-sulfonamido)-2,6-difluoroph enyl]-N-methylimidazo [1,5- a]pyridine-1-carboxamide; 6-[2,6-difluoro-3-(6-fluoro-1-hydroxy-2,3-dihydro-1H-indene- 4-sulfonamido)phenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N,5-dimethyl imidazo[1,5-a]pyridine-1-carboxamide; 2-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido)p henyl]-N-methylimidazo[1,5- b]pyridazine-5-carboxamide; 6-[2,6-difluoro-3-[2-methoxy-5-(trifluoromethyl)pyridine-3-s ulfonamido]phenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-5-fluoro-N- methylimidazo[1,5-a]pyridine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-5-methoxy- N- methylimidazo[1,5-a]pyridine-1-carboxamide; 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N- methylimidazo[1,5-a]pyrimidine-8-carboxamide; 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-2- methoxy-N- methylimidazo[1,5-a] pyrimidine-8-carboxamide; N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a ]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 7-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-8-fluoro-N- methylimidazo[1,5-a]pyridine-3-carboxamide; 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N,1-dimethyl-2- oxoimidazo[1,5-a] pyrimidine-8-carboxamide; 6-[3-[3-cyano-5-(trifluoromethyl)benzenesulfonamido]-2,6-dif luorophenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-methyl-5- (methylamino)imidazo[1,5-a]pyridine-1-carboxamide; 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide; 5-chloro-N-[3,5-difluoro-4-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]pyridin-2-yl]-2- methoxypyridine-3-sulfonamide; (6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide; (6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide; N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6-yl]phenyl]-6-fluoro-1- hydroxy-2,3-dihydro-1H-indene-4-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 7-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N- methylimidazo[1,5-a]pyridine-3-carboxamide; 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(2H-pyrazol-3-yl)imidazo[1,5-a ]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; (6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N,7-dimethyl- 5H,6H,8H-imidazo[1,5-a]pyrazine-1-carboxamide; (6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N,7-dimethyl- 5H,6H,8H-imidazo[1,5-a]pyrazine-1-carboxamide; 5-chloro-N-[2,4-difluoro-3-[1-(3H-1,2,3-triazol-4-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]- 2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin -7-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[ 1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2-cyano-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[ 1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 6-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a ]pyridin-6-yl]phenyl]-1- hydroxy-2,3-dihydro-1H-indene-4-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5-a ]pyridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2-yl)imi dazo[1,5-a]pyridin-7- yl]phenyl]-2-methoxypyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2-yl)imid azo[1,5-a]pyridin-7- yl]phenyl]-2-methoxypyridine-3-sulfonamide; 5-chloro-N-(3-(1-(4-cyano-1H-imidazol-2-yl)imidazo[1,5-a]pyr idin-6-yl)-2,4- difluorophenyl)-2-methoxypyridine-3-sulfonamide; N-[3-[1-(4-cyano-1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl ]-2,4-difluorophenyl] -5- fluoro-2-methylpyridine-3-sulfonamide; N-[3-[1-(4-chloro-1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-y l]-2,4-difluorophenyl] -5- fluoro-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5-a]pyr idin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2-yl)imi dazo[1,5-a]pyridine -6- yl]phenyl]-2-methoxypyridine-3-sulfonamide; 5-chloro-N-(2,4-difluoro-3-[1-[4-(hydroxymethyl)-3H-imidazol -2-yl]imidazo[1,5-a] pyridin- 6-yl]phenyl)-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5- fluoro-2-methylpyridine-3-sulfonamide; N-(2,4-difluoro-3-[1-[4-(hydroxymethyl)-3H-imidazol-2-yl]imi dazo[1,5-a] pyridin-6- yl]phenyl)-5-fluoro-2-methylpyridine-3-sulfonamide; 5-chloro-N-[3-[1-(4-chloro-1H-imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1 ,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5-a]pyr idin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3-triazol-1-yl)imidazo[1, 5-a]pyridin-6-yl] phenyl] -2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3-triazol-2-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2-yl)imi dazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-y l)imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl )imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-5- fluoro-2-methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-y l)imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide; 5-chloro-N-(2,4-difluoro-3-(1-(1-methyl-1H-pyrazol-3-yl)imid azo[1,5-a]pyridin-6- yl)phenyl)-2-methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo [1,5-a]pyridin-6-yl]phenyl] -2- methoxypyridine-3-sulfonamide; (R)-N-(3-(3-(1H-imidazol-2-yl)-5,6,7,8-tetrahydroimidazo[1,5 -a]pyridin-7-yl)-2,4- difluorophenyl)-5-chloro-2-methoxypyridine-3-sulfonamide ; (S)-N-(3-(3-(1H-imidazol-2-yl)-5,6,7,8-tetrahydroimidazo[1,5 -a]pyridin-7-yl)-2,4- difluorophenyl)-5-chloro-2-methoxypyridine-3-sulfonamide ; 5-chloro-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3-yl)imidazo [1,5-a]pyridin-6-yl]phenyl] -2- methylpyridine-3-sulfonamide; N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl] -2,4-difluorophenyl] -5-cyano- 2-methoxypyridine-3-sulfonamide; (R)-6-(2,6-difluoro-3-((5-fluoro-2-methoxypyridine)-3-sulfon amido)phenyl)-N-methyl- 5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamide; (S)-6-(2,6-difluoro-3-((5-fluoro-2-methoxypyridine)-3-sulfon amido)phenyl)-N-methyl- 5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamide; (R)-6-(3-((5-cyano-2-methoxypyridine)-3-sulfonamido)-2,6-dif luorophenyl)-N-methyl- 5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamide; (S)-6-(3-((5-cyano-2-methoxypyridine)-3-sulfonamido)-2,6-dif luorophenyl)-N-methyl- 5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamide; 5-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a ] pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro -2- methoxypyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3-yl)imidazo[ 1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-7-meth yl-5H,6H,8H- imidazo[1,5- a]pyrazin-6-yl]phenyl] -2-methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro- 3-[(6S)-1-(1H-imidazol-2-yl)-7-methyl-5H,6H,8H-imidazo[1,5- a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol -1-yl)imidazo[1,5-a]pyridin-6-yl]phenyl] -5-fluoro-2- methoxypyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo [1,5-a]pyridin-6-yl]phenyl] -2- methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]- 5-fluoro-2 - methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo [1,5-a]pyridin-6-yl] phenyl]- 2- methylpyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyrazin -6-yl] phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide; N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide; N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H,7 H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7 H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl] -2- methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo [1,5- a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[(6S)-1- (1H-imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[5-(1H- imidazol-2-yl)imidazo[1,5-b]pyridazin-2-yl]phenyl] -2- methoxypyridine-3-sulfonamide; (R)-6-(2,6-difluoro-3-((5-fluoro-2-methylpyridine)-3-sulfona mido)phenyl)-N-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide; (S)-6-(2,6-difluoro-3-((5-fluoro-2-methylpyridine)-3-sulfona mido)phenyl)-N-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide; 5-chloro-N-[3-[1-(5-cyclopropyl-4H-1,2,4-triazol-3-yl)imidaz o[1,5-a]pyridin-6-yl]- 2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(5-isopropyl-4H-1,2,4-triazol- 3-yl)imidazo[1,5-a] pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide; (R)-6-(3-((5-chloro-2-methylpyridine)-3-sulfonamido)-2,6-dif luorophenyl)-N-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide; (S)-6-(3-((5-chloro-2-methylpyridine)-3-sulfonamido)-2,6-dif luorophenyl)-N-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide; 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3-sulfonamido) phenyl]-N-methylimidazo [1,5-a]pyrazine-1-carboxamide; 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido)p henyl]-N-methylimidazo [1,5- a]pyrazine-1-carboxamide; 6-[3-(5-cyano-2-methoxypyridine-3-sulfonamido)-2,6-difluorop henyl]-N-methylimidazo[1,5- a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6-difluorop henyl]-N-methylimidazo[1,5- a]pyrazine-1-carboxamide; 5-chloro-N-(2,4-difluoro-3-(1-(hydroxymethyl)imidazo[1,5-a]p yridin-6-yl)phenyl)-2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[5-(1H-imidazol-2-yl)imidazo[1,5- b]pyridazin-2-yl]phenyl] -2- methylpyridine-3-sulfonamide; (5S,6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,5- dimethyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide; (5R,6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,5- dimethyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide; 5-cyano-N-[2,4-difluoro-3-[5-(1H-imidazol- 2-yl)imidazo[1,5-b]pyridazin-2-yl]phenyl]-2- methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[5-(1H-imidazol-2-yl)imidazo[1,5-b]pyridaz in- 2-yl]phenyl]-5-fluoro -2- methoxypyridine-3-sulfonamide; 5-chloro-N-(2,4-difluoro-3-(1-(isoxazol-5-yl)imidazo[1,5-a]p yridin-6-yl)phenyl)-2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(1-hydroxyethyl)imidazo[1,5-a] pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 6-(2-chloro-3-((5-chloro-2-methoxypyridine)-3-sulfonamido)-6 -fluorophenyl)-N- methylimidazo[1,5-a]pyridine-1-carboxamide; 5-chloro-N-(2,4-difluoro-3-[1-[5-(trifluoromethyl)-4H-1,2,4- triazol-3-yl]imidazo[1,5- a]pyridin-6-yl]phenyl)-2-methoxypyridine-3-sulfonamide; 5-chloro-N-[2-chloro-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imi dazo[1,5-a]pyridin-6-yl] phenyl]-2-methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(2H-pyrazol-3-yl)imid azo[1,5-a]pyridin-6-yl]phenyl]- 2-methoxypyridine-3-sulfonamide; 6-[2-chloro-3-(5-chloro-2-methoxypyridine-3-sulfonamido)-6-f luorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5- fluoro-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5- fluoro-2-methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imi dazo[1,5-a]pyridine -6- yl]phenyl]-2-methylpyridine-3-sulfonamide; N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] -2,4-difluorophenyl] -5- chloro-2-methoxypyridine-3-sulfonamide; N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] -2,4-difluorophenyl] -5-fluoro- 2-methoxypyridine-3-sulfonamide; N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] -2,4-difluorophenyl] -5-cyano- 2-methoxypyridine-3-sulfonamide; N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] -2,4-difluorophenyl]-5-chloro- 2-methylpyridine-3-sulfonamide; N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] -2,4-difluorophenyl]-5-fluoro- 2-methylpyridine-3-sulfonamide; N-[3-[1-(4-chloro-1H-imidazol-2-yl)-5-fluoroimidazo[1,5-a]py ridin-6-yl]-2,4- difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide; 5-chloro-N-[3-[1-(4-chloro-1H-imidazol-2-yl)-5-fluoroimidazo [1,5-a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2-cyano-6-fl uorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin- 6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a] pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide; 2-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N- methylimidazo[4,3-b][1,3]thiazole-7-carboxamide; 5-chloro-N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a ]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-6-fluoro-2-m ethylphenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide; 5-cyano-N-[2,4-difluoro-3-[1-(4,5,6,7-tetrahydro-1H-1,3-benz odiazol-2-yl)imidazo [1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-y l)imidazo[1,5-a]pyrazin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin- 6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide; 5-cyano-N-[3-[1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5-a ]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl)imidazo [1,5-a]pyrazin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide; 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl )imidazo[1,5-a]pyrazin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide; N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl)imidazo [1,5-a]pyrazin-6-yl]phenyl]-5- fluoro-2-methylpyridine-3-sulfonamide; 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazo l-3-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfo namide; 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazo l-3-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfo namide; N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5 H,6H,7H,8H-imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide; N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5 H,6H,7H,8H-imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide; 6-(3-((5-chloro-2-oxo-1,2-dihydropyridine)-3-sulfonamido)-2, 6-difluorophenyl)-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-y l)imidazo[1,5-a]pyrazin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide; N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5 H,6H,7H,8H-imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonami de; N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5 H,6H,7H,8H-imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonami de; 5-cyano-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol -3-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfo namide; 5-cyano-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazol -3-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfo namide; 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazo l-3-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfon amide; 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazo l-3-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfon amide; 6-[6-chloro-3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2-f luorophenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide; 2-[6-chloro-3-(5-chloro-2-methylpyridine-3-sulfonamido)-2-fl uorophenyl]-N- methylimidazo[1,5-b]pyridazine-5-carboxamide; 2-[2-chloro-3-(5-chloro-2-methylpyridine-3-sulfonamido)-6-fl uorophenyl]-N- methylimidazo[1,5-b]pyridazine-5-carboxamide; 6-(2-fluoro-5-((5-fluoro-2-methoxypyridine)-3-sulfonamido)ph enyl)-N-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide; 6-(6-chloro-3-((5-chloro-2-methoxypyridine)-3-sulfonamido)-2 -fluorophenyl)-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; N-[4-chloro-2-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide; 5-chloro-N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl)-2,4- difluorophenyl)-2-methoxypyridine-3-sulfonamide; N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6-yl)- 2,4-difluorophenyl)-5- fluoro-2-methoxypyridine-3-sulfonamide; N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6-yl)-2,4-difluorophenyl)-5- fluoro-2-methylpyridine-3-sulfonamide; 5-chloro-N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl) -2,4- difluorophenyl)-2-methylpyridine-3-sulfonamide; 5-chloro-N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H-benzo[d ]imidazol-2-yl) imidazo[1,5- a]pyridin-6-yl)phenyl)-2-methoxypyridine-3-sulfonamide; N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H-benzo[d]imidazol -2-yl)imidazo [1,5-a]pyridin-6- yl)phenyl)-5-fluoro-2-methoxypyridine-3-sulfonamide; N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H-benzo[d]imidazol -2-yl) imidazo[1,5-a]pyridin-6- yl)phenyl)-5-fluoro-2-methylpyridine-3-sulfonamide; 5-chloro-N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H-benzo[d ]imidazol-2 -yl)imidazo[1,5- a]pyridin-6-yl)phenyl)-2-methylpyridine-3-sulfonamide; N-[2-chloro-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide; (6R)-6-[2-chloro-6-fluoro-3-(5-fluoro-2-methoxypyridine-3-su lfonamido)phenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide; (6S)-6-[2-chloro-6-fluoro-3-(5-fluoro-2-methoxypyridine-3-su lfonamido)phenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide; methyl 2-[6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]imidazo[1,5-a]pyrazin-1-yl]-3H-1,3-benzod iazole-5-carboxylate; (6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N-methyl- 5H,6H,8H-imidazo[4,3-c][1,4]oxazine-1-carboxamide; (6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N-methyl- 5H,6H,8H-imidazo[4,3-c][1,4]oxazine-1-carboxamide; (6R)-6-[6-chloro-2-fluoro-3-(5-fluoro-2-methoxypyridine-3-su lfonamido)phenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide; (6S)-6-[6-chloro-2-fluoro-3-(5-fluoro-2-methoxypyridine-3-su lfonamido)phenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide; N-[2,4-difluoro-3-[1-(4-phenyl-1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N- isopropylimidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-(2- methylpropyl)imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-(2,2,2- trifluoroethyl)imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-5-fluoro-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-(2- hydroxyethyl)imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-(1-methylpyrazol- 4-yl)imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-(oxan-4- ylmethyl)imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-(2- methanesulfonylethyl)imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-ethylimidazo[1,5- a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N- (cyclopropylmethyl)imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-ethoxypyridine-3-sulfonamido)-2,6-difluorop henyl]-N-methylimidazo[1,5- a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-isopropoxypyridine-3-sulfonamido)-2,6-diflu orophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-cyclopropoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3-sulfonamido) phenyl]-5-fluoro-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]imidazo[1,5- a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-[3- (dimethylamino)propyl]imidazo[1,5-a]pyrazine-1-carboxamide; (R)-6-(3-((5-chloro-2-methoxypyridine)-3-sulfonamido)-2,6-di fluorophenyl)-N-(1- methylpyrrolidin-3-yl)imidazo[1,5-a]pyrazine-1-carboxamide; (S)-6-(3-((5-chloro-2-methoxypyridine)-3-sulfonamido)-2,6-di fluorophenyl)-N-(1- methylpyrrolidin-3-yl)imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-(1,2-oxazol-4- yl)imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-[2-(morpholin-4- yl)ethyl]imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-[5-chloro-2-(2-methylpropoxy)pyridine-3-sulfonamido]-2, 6-difluorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; N-[3-[1-(5-cyclopropyl-3H-imidazol-4-yl)imidazo[1,5-a]pyrazi n-6-yl]-2,4-difluorophenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide; N-[3-[1-(4-benzyl-1H-imidazol-2-yl)imidazo[1,5-a]pyrazin-6-y l]-2,4-difluorophenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-[2- (dimethylamino)ethyl]imidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-[2-(2- oxopyrrolidin-1-yl)ethyl]imidazo[1,5-a]pyrazine-1-carboxamid e; 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-[4- [(dimethylamino)methyl]phenyl]imidazo[1,5-a]pyrazine-1-carbo xamide; 6-[3-[5-chloro-2-(2,2,2-trifluoroethoxy)pyridine-3-sulfonami do]-2,6-difluorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; 6-[3-[2-(benzyloxy)-5-chloropyridine-3-sulfonamido]-2,6-difl uorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido)p henyl]-5-fluoro-N- methylimidazo[1,5-a]pyrazine-1-carboxamide; N-(2,4-difluoro-3-[1-[5-(4-methylpiperazin-1-yl)-3H-1,3-benz odiazol-2-yl]imidazo[1,5- a]pyridin-6-yl]phenyl)-5-fluoro-2-methoxypyridine-3-sulfonam ide; and 6-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6-difluorop henyl]-5-fluoro-N- methylimidazo [1,5-a]pyrazine-1-carboxamide; or a pharmaceutically acceptable salt thereof. Therapeutic Applications GCN2 Modulating (Inhibiting/Activating) Compounds [0114] It is contemplated that GCN2 modulating (inhibiting/activating) compounds and related compounds described herein, such as a compound of Formula I, provide therapeutic benefits to subjects suffering from cancer, neurodegenerative disease, and doxorubicin- induced cardiotoxicity. Accordingly, one aspect of the invention provides therapeutic methods for treating the foregoing diseases and conditions using GCN2 modulating (inhibiting/activating) compounds and related compounds described herein. Various aspects and embodiments of the therapeutic methods are described below. Cancer [0115] One aspect of the invention provides a method of treating cancer in a subject. The method comprises administering a therapeutically effective amount of a GCN2 modulating (inhibiting/activating) compound or related compound described herein, such as a compound of Formula 1 to a subject in need thereof to treat the cancer. In certain embodiments, the particular compound of Formula I, is a compound defined by one of the embodiments described above. [0116] In certain embodiments, the cancer is a solid tumor, leukemia, or lymphoma. In certain embodiments, the cancer is colon cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, lung cancer, bladder cancer, stomach cancer, cervical cancer, testicular cancer, skin cancer, rectal cancer, sweat gland carcinoma, sebaceous gland carcinoma, thyroid cancer, kidney cancer, uterus cancer, esophagus cancer, liver cancer, head cancer, neck cancer, throat cancer, mouth cancer, bone cancer, chest cancer, lymph node cancer, eye cancer, mesothelioma, an acoustic neuroma, oligodendroglioma, meningioma, neuroblastoma, retinoblastoma, leukemia, or lymphoma. In certain embodiments, the cancer is colon cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, lung cancer, bladder cancer, stomach cancer, cervical cancer, testicular cancer, skin cancer, rectal cancer, leukemia, or lymphoma. In certain other embodiments, the cancer is colon cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, lung cancer, leukemia, bladder cancer, stomach cancer, cervical cancer, testicular cancer, skin cancer, rectal cancer, thyroid cancer, kidney cancer, uterus cancer, esophagus cancer, liver cancer, an acoustic neuroma, oligodendroglioma, meningioma, neuroblastoma, or retinoblastoma. In certain other embodiments, the cancer is small cell lung cancer, non-small cell lung cancer, melanoma, cancer of the central nervous system tissue, brain cancer, Hodgkin’s lymphoma, non- Hodgkin’s lymphoma, cutaneous T-Cell lymphoma, cutaneous B-Cell lymphoma, or diffuse large B-Cell lymphoma. In certain other embodiments, the cancer is breast cancer, colon cancer, small-cell lung cancer, non-small cell lung cancer, prostate cancer, renal cancer, ovarian cancer, leukemia, melanoma, or cancer of the central nervous system tissue. In certain other embodiments, the cancer is colon cancer, small-cell lung cancer, non-small cell lung cancer, renal cancer, ovarian cancer, renal cancer, or melanoma. [0117] Additional exemplary cancers include fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, Ewing’s tumor, leiomyosarcoma, rhabdomyosarcoma, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms’ tumor, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, and hemangioblastoma. [0118] In certain embodiments, the cancer is a neuroblastoma, meningioma, hemangiopericytoma, multiple brain metastase, glioblastoma multiforms, glioblastoma, brain stem glioma, poor prognosis malignant brain tumor, malignant glioma, anaplastic astrocytoma, anaplastic oligodendroglioma, neuroendocrine tumor, rectal adeno carcinoma, Dukes C & D colorectal cancer, unresectable colorectal carcinoma, metastatic hepatocellular carcinoma, Kaposi’s sarcoma, karotype acute myeloblastic leukemia, Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, cutaneous T-Cell lymphoma, cutaneous B-Cell lymphoma, diffuse large B-Cell lymphoma, low grade follicular lymphoma, metastatic melanoma, localized melanoma, malignant mesothelioma, malignant pleural effusion mesothelioma syndrome, peritoneal carcinoma, papillary serous carcinoma, gynecologic sarcoma, soft tissue sarcoma, scelroderma, cutaneous vasculitis, Langerhans cell histiocytosis, leiomyosarcoma, fibrodysplasia ossificans progressive, hormone refractory prostate cancer, resected high-risk soft tissue sarcoma, unrescectable hepatocellular carcinoma, Waidenstrom’s macroglobulinemia, smoldering myeloma, indolent myeloma, fallopian tube cancer, androgen independent prostate cancer, androgen dependent stage IV non-metastatic prostate cancer, hormone-insensitive prostate cancer, chemotherapy-insensitive prostate cancer, papillary thyroid carcinoma, follicular thyroid carcinoma, medullary thyroid carcinoma, or leiomyoma. [0119] In certain embodiments, the cancer is colon cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, lung cancer, bladder cancer, stomach cancer, cervical cancer, testicular cancer, skin cancer, rectal cancer, sweat gland carcinoma, sebaceous gland carcinoma, thyroid cancer, kidney cancer, uterus cancer, esophagus cancer, liver cancer, head cancer, neck cancer, throat cancer, mouth cancer, bone cancer, chest cancer, lymph node cancer, eye cancer, mesothelioma, an acoustic neuroma, oligodendroglioma, meningioma, neuroblastoma, retinoblastoma, leukemia, or lymphoma. Neurodegenerative Disease [0120] Another aspect of the invention provides a method of treating a neurodegenerative disease in a subject. The method comprises administering a therapeutically effective amount of a compound described herein, such as a compound of Formula I, to a subject in need thereof to treat the neurodegenerative disease. In certain embodiments, the neurodegenerative disease is Alzheimer’s disease, Parkinson's Disease, Huntington’s Disease, amyotrophic lateral sclerosis, or spinocerebellar ataxia. [0121] Aberrant autophagic processes contribute to neurodegenerative diseases. For example, γ-secretase activity is enhanced in autophagic vacuoles through signal transduction mediated by GCN2 phosphorylation of the α subunit of eukaryotic initiation factor 2 (eIF2α) (see, e.g., Ohta, K. et al. in Autophagy 2010, 6, 345-352). The γ-secretase enhances amyloid- β synthesis and the progression of Alzheimer’s disease. Accordingly, compounds having inhibitory activity towards GCN2 provide benefits to patients suffering from neurodegenerative diseases. [0122] In certain embodiments, the cancer is colon cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, lung cancer, bladder cancer, stomach cancer, cervical cancer, testicular cancer, skin cancer, rectal cancer, leukemia, or lymphoma. Doxorubicin-induced Cardiotoxicity [0123] Another aspect of the invention provides a method of treating doxorubicin-induced cardiotoxicity in a subject. The method comprises administering a therapeutically effective amount of a compound described herein, such as a compound of Formula I, to a subject in need thereof suffering from doxorubicin-induced cardiotoxicity, to thereby treat the doxorubicin-induced cardiotoxicity. [0124] Another aspect of the invention provides a method of preventing doxorubicin-induced cardiotoxicity in a subject. The method comprises administering a therapeutically effective amount of a compound described herein, such as a compound of Formula I, to a subject in need thereof that has received, or will receive, doxorubicin, to thereby prevent doxorubicin- induced cardiotoxicity. [0125] Deficiency in GCN2 has been reported to ameliorate doxorubicin-induced cardiotoxicity. See, for example, Wang et al. in Redox Biology (2018) vol.17, pages 25-34. Accordingly, compounds having inhibitory activity towards GCN2 provide benefits to patients suffering from or likely to suffer from doxorubicin-induced cardiotoxicity. [0126] In certain embodiments, the subject is a human. [0127] Another aspect of the invention provides for the use of a compound described herein (such as a compound of Formula I) in the manufacture of a medicament. In certain embodiments, the medicament is for treating a disorder described herein, such as cancer. [0128] Another aspect of the invention provides for the use of a compound described herein (such as a compound of Formula I) for treating a medical disorder, such a medical disorder described herein (e.g., cancer). [0129] Further, it is contemplated that GCN2 modulators (inhibitors/activators) and related compounds described herein, such as a compound of Formula I, can inhibit/activate the activity of GCN2. Accordingly, another aspect of the invention provides a method of inhibiting/activating the activity of GCN2. The method comprises exposing a GCN2 to an effective amount of an GCN2 modulator (inhibitor/activator) or related compound described herein, such as a compound of Formula I, to inhibit/activate GCN2 activity. In certain embodiments, the particular compound of Formula I, is the compound defined by one of the embodiments described above. Combination Therapy [0130] Another aspect of the invention provides for combination therapy. GCN2 modulators (inhibitors/activators) and related compounds (e.g., a compound of Formula I) or their pharmaceutically acceptable salts may be used in combination with additional therapeutic agents to treat medical disorders, such as a cancer. [0131] Exemplary therapeutic agents that may be used as part of a combination therapy in treating cancer, include, for example, mitomycin, tretinoin, ribomustin, gemcitabine, vincristine, etoposide, cladribine, mitobronitol, methotrexate, doxorubicin, carboquone, pentostatin, nitracrine, zinostatin, cetrorelix, letrozole, raltitrexed, daunorubicin, fadrozole, fotemustine, thymalfasin, sobuzoxane, nedaplatin, cytarabine, bicalutamide, vinorelbine, vesnarinone, aminoglutethimide, amsacrine, proglumide, elliptinium acetate, ketanserin, doxifluridine, etretinate, isotretinoin, streptozocin, nimustine, vindesine, flutamide, drogenil, butocin, carmofur, razoxane, sizofilan, carboplatin, mitolactol, tegafur, ifosfamide, prednimustine, picibanil, levamisole, teniposide, improsulfan, enocitabine, lisuride, oxymetholone, tamoxifen, progesterone, mepitiostane, epitiostanol, formestane, interferon- alpha, interferon-2 alpha, interferon-beta, interferon-gamma, colony stimulating factor-1, colony stimulating factor-2, denileukin diftitox, interleukin-2, and leutinizing hormone releasing factor. [0132] Radiation therapy may also be used as part of a combination therapy. [0133] An additional class of agents that may be used as part of a combination therapy in treating cancer is immune checkpoint inhibitors (also referred to as immune checkpoint blockers). Immune checkpoint inhibitors are a class of therapeutic agents that have the effect of blocking immune checkpoints. See, for example, Pardoll in Nature Reviews Cancer (2012) vol.12, pages 252-264. Exemplary immune checkpoint inhibitors include agents that inhibit one or more of (i) cytotoxic T‑lymphocyte-associated antigen 4 (CTLA4), (ii) programmed cell death protein 1 (PD1), (iii) PDL1, (iv) LAB3, (v) B7-H3, (vi) B7-H4, and (vii) TIM3. The CTLA4 inhibitor Ipilumumab has been approved by the United States Food and Drug Administration for treating melanoma. [0134] Yet other agents that may be used as part of a combination therapy in treating cancer are monoclonal antibody agents that target non-checkpoint targets (e.g., herceptin) and non- cytoxic agents (e.g., tyrosine-kinase inhibitors). [0135] Yet other agents that may be used as part of a combination therapy in treating cancer are agents which deplete amino acids or other nutrients, radiation, and agents that provoke the integrated stress response or that promote autophagy. Such agents may include aspariginase, argininase inhibitors of kinases such a b-Raf, and cytotoxic agents such as cis-platin. [0136] Accordingly, another aspect of the invention provides a method of treating cancer in a patient, where the method comprises administering to the patient in need thereof (i) a therapeutically effective amount of a GCN2 modulator (activator/inhibitor) compound described herein and (ii) a second anti-cancer agent, in order to treat the cancer, where the second therapeutic agent may be one of the additional therapeutic agents described above (e.g., mitomycin, tretinoin, ribomustin, gemcitabine, an immune checkpoint inhibitor, or a monoclonal antibody agent that targets non-checkpoint targets) or one of the following: • an inhibitor selected from an ALK Inhibitor, an ATR Inhibitor, an A2A Antagonist, a Base Excision Repair Inhibitor, a Bcr-Abl Tyrosine Kinase Inhibitor, a Bruton’s Tyrosine Kinase Inhibitor, a CDC7 Inhibitor, a CHK1 Inhibitor, a Cyclin-Dependent Kinase Inhibitor, a DNA-PK Inhibitor, an Inhibitor of both DNA-PK and mTOR, a DNMT1 Inhibitor, a DNMT1 Inhibitor plus 2-chloro-deoxyadenosine, an HDAC Inhibitor, a Hedgehog Signaling Pathway Inhibitor, an IDO Inhibitor, a JAK Inhibitor, a mTOR Inhibitor, a MEK Inhibitor, a MELK Inhibitor, a MTH1 Inhibitor, a PARP Inhibitor, a Phosphoinositide 3-Kinase Inhibitor, an Inhibitor of both PARP1 and DHODH, a Proteasome Inhibitor, a Topoisomerase-II Inhibitor, a Tyrosine Kinase Inhibitor, a VEGFR Inhibitor, and a WEE1 Inhibitor; • an agonist of OX40, CD137, CD40, GITR, CD27, HVEM, TNFRSF25, or ICOS; • a therapeutic antibody targeting one of the following: CD20, CD30, CD33, CD52, EpCAM, CEA, gpA33, a mucin, TAG-72, CAIX, PSMA, a folate-binding protein, a ganglioside, Le, VEGF, VEGFR, VEGFR2, integrin αVβ3, integrin α5β1, EGFR, ERBB2, ERBB3, MET, IGF1R, EPHA3, TRAILR1, TRAILR2, RANKL, FAP, tenascin, CD19, KIR, NKG2A, CD47, CEACAM1, c-MET, VISTA, CD73, CD38, BAFF, interleukin-1 beta, B4GALNT1, interleukin-6, and interleukin-6 receptor; • a cytokine selected from IL-12, IL-15, GM-CSF, and G-CSF; • a therapeutic agent selected from sipuleucel-T, aldesleukin (a human recombinant interleukin-2 product having the chemical name des-alanyl-1, serine-125 human interleukin- 2), dabrafenib (a kinase inhibitor having the chemical name N-{3-[5-(2-aminopyrimidin-4- yl)-2-tert-butyl-1,3-thiazol-4-yl]-2-fluorophenyl}-2,6-diflu orobenzenesulfonamide), vemurafenib (a kinase inhibitor having the chemical name propane-1-sulfonic acid {3-[5-(4- chlorophenyl)-1H-pyrrolo[2,3-b]pyridine-3-carbonyl]-2,4-difl uoro-phenyl}-amide), and 2- chloro-deoxyadenosine; or • a placental growth factor, an antibody-drug conjugate, an oncolytic virus, or an anti- cancer vaccine. [0137] In certain embodiments, the second anti-cancer agent is an ALK Inhibitor. In certain embodiments, the second anti-cancer agent is an ALK Inhibitor comprising ceritinib or crizotinib. In certain embodiments, the second anti-cancer agent is an ATR Inhibitor. In certain embodiments, the second anti-cancer agent is an ATR Inhibitor comprising AZD6738 or VX-970. In certain embodiments, the second anti-cancer agent is an A2A Antagonist. In certain embodiments, the second anti-cancer agent is a Base Excision Repair Inhibitor comprising methoxyamine. In certain embodiments, the second anti-cancer agent is a Base Excision Repair Inhibitor, such as methoxyamine. In certain embodiments, the second anti- cancer agent is a Bcr-Abl Tyrosine Kinase Inhibitor. In certain embodiments, the second anti-cancer agent is a Bcr-Abl Tyrosine Kinase Inhibitor comprising dasatinib or nilotinib. In certain embodiments, the second anti-cancer agent is a Bruton’s Tyrosine Kinase Inhibitor. In certain embodiments, the second anti-cancer agent is a Bruton’s Tyrosine Kinase Inhibitor comprising ibrutinib. In certain embodiments, the second anti-cancer agent is a CDC7 Inhibitor. In certain embodiments, the second anti-cancer agent is a CDC7 Inhibitor comprising RXDX-103 or AS-141. [0138] In certain embodiments, the second anti-cancer agent is a CHK1 Inhibitor. In certain embodiments, the second anti-cancer agent is a CHK1 Inhibitor comprising MK-8776, ARRY-575, or SAR-020106. In certain embodiments, the second anti-cancer agent is a Cyclin-Dependent Kinase Inhibitor. In certain embodiments, the second anti-cancer agent is a Cyclin-Dependent Kinase Inhibitor comprising palbociclib. In certain embodiments, the second anti-cancer agent is a DNA-PK Inhibitor. In certain embodiments, the second anti- cancer agent is a DNA-PK Inhibitor comprising MSC2490484A. In certain embodiments, the second anti-cancer agent is Inhibitor of both DNA-PK and mTOR. In certain embodiments, the second anti-cancer agent comprises CC-115. [0139] In certain embodiments, the second anti-cancer agent is a DNMT1 Inhibitor. In certain embodiments, the second anti-cancer agent is a DNMT1 Inhibitor comprising decitabine, RX-3117, guadecitabine, NUC-8000, or azacytidine. In certain embodiments, the second anti-cancer agent comprises a DNMT1 Inhibitor and 2-chloro-deoxyadenosine. In certain embodiments, the second anti-cancer agent comprises ASTX-727. [0140] In certain embodiments, the second anti-cancer agent is a HDAC Inhibitor. In certain embodiments, the second anti-cancer agent is a HDAC Inhibitor comprising OBP-801, CHR- 3996, etinostate, resminostate, pracinostat, CG-200745, panobinostat, romidepsin, mocetinostat, belinostat, AR-42, ricolinostat, KA-3000, or ACY-241. [0141] In certain embodiments, the second anti-cancer agent is a Hedgehog Signaling Pathway Inhibitor. In certain embodiments, the second anti-cancer agent is a Hedgehog Signaling Pathway Inhibitor comprising sonidegib or vismodegib. In certain embodiments, the second anti-cancer agent is an IDO Inhibitor. In certain embodiments, the second anti- cancer agent is an IDO Inhibitor comprising INCB024360. In certain embodiments, the second anti-cancer agent is a JAK Inhibitor. In certain embodiments, the second anti-cancer agent is a JAK Inhibitor comprising ruxolitinib or tofacitinib. In certain embodiments, the second anti-cancer agent is a mTOR Inhibitor. In certain embodiments, the second anti- cancer agent is a mTOR Inhibitor comprising everolimus or temsirolimus. In certain embodiments, the second anti-cancer agent is a MEK Inhibitor. In certain embodiments, the second anti-cancer agent is a MEK Inhibitor comprising cobimetinib or trametinib. In certain embodiments, the second anti-cancer agent is a MELK Inhibitor. In certain embodiments, the second anti-cancer agent is a MELK Inhibitor comprising ARN-7016, APTO-500, or OTS- 167. In certain embodiments, the second anti-cancer agent is a MTH1 Inhibitor. In certain embodiments, the second anti-cancer agent is a MTH1 Inhibitor comprising (S)-crizotinib, TH287, or TH588. [0142] In certain embodiments, the second anti-cancer agent is a PARP Inhibitor. In certain embodiments, the second anti-cancer agent is a PARP Inhibitor comprising MP-124, olaparib, BGB-290, talazoparib, veliparib, niraparib, E7449, rucaparb, or ABT-767. In certain embodiments, the second anti-cancer agent is a Phosphoinositide 3-Kinase Inhibitor. In certain embodiments, the second anti-cancer agent is a Phosphoinositide 3-Kinase Inhibitor comprising idelalisib. In certain embodiments, the second anti-cancer agent is an inhibitor of both PARP1 and DHODH (i.e., an agent that inhibits both poly ADP ribose polymerase 1 and dihydroorotate dehydrogenase). [0143] In certain embodiments, the second anti-cancer agent is a Proteasome Inhibitor. In certain embodiments, the second anti-cancer agent is a Proteasome Inhibitor comprising bortezomib or carfilzomib. In certain embodiments, the second anti-cancer agent is a Topoisomerase-II Inhibitor. In certain embodiments, the second anti-cancer agent is a Topoisomerase-II Inhibitor comprising vosaroxin. [0144] In certain embodiments, the second anti-cancer agent is a Tyrosine Kinase Inhibitor. In certain embodiments, the second anti-cancer agent is a Tyrosine Kinase Inhibitor comprising bosutinib, cabozantinib, imatinib or ponatinib. In certain embodiments, the second anti-cancer agent is a VEGFR Inhibitor. In certain embodiments, the second anti- cancer agent is a VEGFR Inhibitor comprising regorafenib. In certain embodiments, the second anti-cancer agent is a WEE1 Inhibitor. In certain embodiments, the second anti- cancer agent is a WEE1 Inhibitor comprising AZD1775. [0145] In certain embodiments, the second anti-cancer agent is an agonist of OX40, CD137, CD40, GITR, CD27, HVEM, TNFRSF25, or ICOS. In certain embodiments, the second anti- cancer agent is a therapeutic antibody selected from the group consisting of rituximab, ibritumomab tiuxetan, tositumomab, obinutuzumab, ofatumumab, brentuximab vedotin, gemtuzumab ozogamicin, alemtuzumab, IGN101, adecatumumab, labetuzumab, huA33, pemtumomab, oregovomab, minetumomab, cG250, J591, Mov18, farletuzumab, 3F8, ch14.18, KW-2871, hu3S193, lgN311, bevacizumab, IM-2C6, pazopanib, sorafenib, axitinib, CDP791, lenvatinib, ramucirumab, etaracizumab, volociximab, cetuximab, panitumumab, nimotuzumab, 806, afatinib, erlotinib, gefitinib, osimertinib, vandetanib, trastuzumab, pertuzumab, MM-121, AMG 102, METMAB, SCH 900105, AVE1642, IMC-A12, MK- 0646, R1507, CP 751871, KB004, IIIA-4, mapatumumab, HGS-ETR2, CS-1008, denosumab, sibrotuzumab, F19, 81C6, MEDI551, lirilumab, MEDI9447, daratumumab, belimumab, canakinumab, dinutuximab, siltuximab, and tocilizumab. [0146] In certain embodiments, the second anti-cancer agent is a placental growth factor. In certain embodiments, the second anti-cancer agent is a placental growth factor comprising ziv-aflibercept. In certain embodiments, the second anti-cancer agent is an antibody-drug conjugate. In certain embodiments, the second anti-cancer agent is an antibody-drug conjugate selected from the group consisting of brentoxumab vedotin and trastuzumab emtransine. [0147] In certain embodiments, the second anti-cancer agent is an oncolytic virus. In certain embodiments, the second anti-cancer agent is the oncolytic virus talimogene laherparepvec. In certain embodiments, the second anti-cancer agent is an anti-cancer vaccine. In certain embodiments, the second anti-cancer agent is an anti-cancer vaccine selected from the group consisting of a GM-CSF tumor vaccine, a STING/GM-CSF tumor vaccine, and NY-ESO-1. In certain embodiments, the second anti-cancer agent is a cytokine selected from IL-12, IL- 15, GM-CSF, and G-CSF. [0148] In certain embodiments, the second anti-cancer agent is a therapeutic agent selected from sipuleucel-T, aldesleukin (a human recombinant interleukin-2 product having the chemical name des-alanyl-1, serine-125 human interleukin-2), dabrafenib (a kinase inhibitor having the chemical name N-{3-[5-(2-aminopyrimidin-4-yl)-2-tert-butyl-1,3-thiazol-4-y l]-2- fluorophenyl}-2,6-difluorobenzenesulfonamide), vemurafenib (a kinase inhibitor having the chemical name propane-1-sulfonic acid {3-[5-(4-chlorophenyl)-1H-pyrrolo[2,3-b]pyridine-3- carbonyl]-2,4-difluoro-phenyl}-amide), and 2-chloro-deoxyadenosine. [0149] The doses and dosage regimen of the active ingredients used in the combination therapy may be determined by an attending clinician. In certain embodiments, the GCN2 modulator (inhibitor/activator) or related compound (e.g., a compound of any one of Formula I) and the additional therapeutic agent(s) are administered in doses commonly employed when such agents are used as monotherapy for treating the disorder. In other embodiments, the GCN2 modulator (inhibitor/activator) or related compound (e.g., a compound of any one of Formula I) and the additional therapeutic agent(s) are administered in doses lower than the doses commonly employed when such agents are used as monotherapy for treating the disorder. In certain embodiments, GCN2 modulator (inhibitor/activator) or related compound (e.g., a compound of any one of Formula I) and the additional therapeutic agent(s) are present in the same composition, which is suitable for oral administration. [0150] In certain embodiments, the GCN2 modulator (inhibitor/activator) or related compound (e.g., a compound of any one of Formula I) and the additional therapeutic agent(s) may act additively or synergistically. A synergistic combination may allow the use of lower dosages of one or more agents and/or less frequent administration of one or more agents of a combination therapy. A lower dosage or less frequent administration of one or more agents may lower toxicity of the therapy without reducing the efficacy of the therapy. [0151] Another aspect of this invention is a kit comprising a therapeutically effective amount of the GCN2 modulator (inhibitor/activator) or related compound (e.g., a compound of any one of Formula I), a pharmaceutically acceptable carrier, vehicle or diluent, and optionally at least one additional therapeutic agent listed above. Pharmaceutical Compositions and Dosing Considerations [0152] As indicated above, the invention provides pharmaceutical compositions, which comprise a therapeutically-effective amount of one or more of the compounds described above, formulated together with one or more pharmaceutically acceptable carriers (additives) and/or diluents. The pharmaceutical compositions may be specially formulated for administration in solid or liquid form, including those adapted for the following: (1) oral administration, for example, drenches (aqueous or non-aqueous solutions or suspensions), tablets, e.g., those targeted for buccal, sublingual, and systemic absorption, boluses, powders, granules, pastes for application to the tongue; (2) parenteral administration, for example, by subcutaneous, intramuscular, intravenous or epidural injection as, for example, a sterile solution or suspension, or sustained-release formulation; (3) topical application, for example, as a cream, ointment, or a controlled-release patch or spray applied to the skin; (4) intravaginally or intrarectally, for example, as a pessary, cream or foam; (5) sublingually; (6) ocularly; (7) transdermally; or (8) nasally. [0153] The phrase “therapeutically-effective amount” as used herein means that amount of a compound, material, or composition comprising a compound of the present invention which is effective for producing some desired therapeutic effect in at least a sub-population of cells in an animal at a reasonable benefit/risk ratio applicable to any medical treatment. [0154] The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. [0155] Wetting agents, emulsifiers and lubricants, as well as coloring agents, release agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the compositions. [0156] Formulations of the present invention include those suitable for oral, nasal, topical (including buccal and sublingual), rectal, vaginal and/or parenteral administration. The formulations may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. The amount of active ingredient which can be combined with a carrier material to produce a single dosage form will vary depending upon the host being treated, the particular mode of administration. The amount of active ingredient which can be combined with a carrier material to produce a single dosage form will generally be that amount of the compound which produces a therapeutic effect. Generally, out of one hundred percent, this amount will range from about 0.1 percent to about ninety-nine percent of active ingredient, preferably from about 5 percent to about 70 percent, most preferably from about 10 percent to about 30 percent. [0157] In certain embodiments, a formulation of the present invention comprises an excipient selected from the group consisting of cyclodextrins, celluloses, liposomes, micelle forming agents, and a compound of the present invention. In certain embodiments, an aforementioned formulation renders orally bioavailable a compound of the present invention. [0158] Methods of preparing these formulations or compositions include the step of bringing into association a compound of the present invention with the carrier and, optionally, one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association a compound of the present invention with liquid carriers, or finely divided solid carriers, or both, and then, if necessary, shaping the product. [0159] Formulations of the invention suitable for oral administration may be in the form of capsules, cachets, pills, tablets, lozenges (using a flavored basis), powders, granules, or as a solution or a suspension in an aqueous or non-aqueous liquid, or as an oil-in-water or water- in-oil liquid emulsion, or as an elixir or syrup, or as pastilles (using an inert base) and/or as mouth washes and the like, each containing a predetermined amount of a compound of the present invention as an active ingredient. A compound of the present invention may also be administered as a bolus, electuary or paste. [0160] In solid dosage forms of the invention for oral administration (capsules, tablets, pills, dragees, powders, granules, trouches and the like), the active ingredient is mixed with one or more pharmaceutically-acceptable carriers and/or any of the following: (1) fillers or extenders; (2) binders; (3) humectants; (4) disintegrating agents; (5) solution retarding agents; (6) absorption accelerators, such as quaternary ammonium compounds and surfactants; (7) wetting agents; (8) absorbents; (9) lubricants; (10) coloring agents; and (11) controlled release agents. In the case of capsules, tablets and pills, the pharmaceutical compositions may also comprise buffering agents. [0161] A tablet may be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared using binder, lubricant, inert diluent, preservative, disintegrant, surface-active or dispersing agent. Molded tablets may be made by molding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. [0162] The tablets, and other solid dosage forms of the pharmaceutical compositions of the present invention, such as dragees, capsules, pills and granules, may optionally be scored or prepared with coatings and shells, such as enteric coatings and other coatings well known in the pharmaceutical-formulating art. They may also be formulated so as to provide slow or controlled release of the active ingredient therein using, for example, hydroxypropylmethyl cellulose in varying proportions to provide the desired release profile, other polymer matrices, liposomes and/or microspheres. They may be formulated for rapid release, e.g., freeze-dried. They may be sterilized by, for example, filtration through a bacteria-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved in sterile water, or some other sterile injectable medium immediately before use. These compositions may also optionally contain opacifying agents and may be of a composition that they release the active ingredient(s) only, or preferentially, in a certain portion of the gastrointestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes. The active ingredient can also be in micro-encapsulated form, if appropriate, with one or more of the above-described excipients. [0163] Liquid dosage forms for oral administration of the compounds of the invention include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to the active ingredient, the liquid dosage forms may contain inert diluents commonly used in the art, such as, for example, water or other solvents, solubilizing agents and emulsifiers. [0164] Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, coloring, perfuming and preservative agents. [0165] Suspensions, in addition to the active compounds, may contain suspending agents. [0166] Formulations of the pharmaceutical compositions of the invention for rectal or vaginal administration may be presented as a suppository, which may be prepared by mixing one or more compounds of the invention with one or more suitable nonirritating excipients or carriers which is solid at room temperature, but liquid at body temperature and, therefore, will melt in the rectum or vaginal cavity and release the active compound. [0167] Formulations of the present invention which are suitable for vaginal administration also include pessaries, tampons, creams, gels, pastes, foams or spray formulations containing such carriers as are known in the art to be appropriate. [0168] Dosage forms for the topical or transdermal administration of a compound of this invention include powders, sprays, ointments, pastes, creams, lotions, gels, solutions, patches and inhalants. The active compound may be mixed under sterile conditions with a pharmaceutically-acceptable carrier, and with any preservatives, buffers, or propellants which may be required. [0169] Transdermal patches have the added advantage of providing controlled delivery of a compound of the present invention to the body. Such dosage forms can be made by dissolving or dispersing the compound in the proper medium. Absorption enhancers can also be used to increase the flux of the compound across the skin. The rate of such flux can be controlled by either providing a rate controlling membrane or dispersing the compound in a polymer matrix or gel. [0170] Ophthalmic formulations, eye ointments, powders, solutions and the like, are also contemplated as being within the scope of this invention. [0171] Pharmaceutical compositions of this invention suitable for parenteral administration comprise one or more compounds of the invention in combination with one or more pharmaceutically-acceptable sterile isotonic aqueous or nonaqueous solutions, dispersions, suspensions or emulsions, or sterile powders which may be reconstituted into sterile injectable solutions or dispersions just prior to use, which may contain sugars, alcohols, antioxidants, buffers, bacteriostats, solutes which render the formulation isotonic with the blood of the intended recipient or suspending or thickening agents. [0172] Proper fluidity can be maintained, for example, by the use of coating materials, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants. [0173] These compositions may also contain adjuvants such as preservatives, wetting agents, emulsifying agents and dispersing agents. Prevention of the action of microorganisms upon the subject compounds may be ensured by the inclusion of various antibacterial and antifungal agents. It may also be desirable to include isotonic agents into the compositions. In addition, prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin. [0174] In some cases, in order to prolong the effect of a drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material having poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally-administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle. [0175] Injectable depot forms are made by forming microencapsule matrices of the subject compounds in biodegradable polymers. Depending on the ratio of drug to polymer, and the nature of the particular polymer employed, the rate of drug release can be controlled. Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissue. [0176] When the compounds of the present invention are administered as pharmaceuticals, to humans and animals, they can be given per se or as a pharmaceutical composition containing, for example, 0.1 to 99% (more preferably, 10 to 30%) of active ingredient in combination with a pharmaceutically acceptable carrier. [0177] The preparations of the present invention may be given orally, parenterally, topically, or rectally. They are of course given in forms suitable for each administration route. For example, they are administered in tablets or capsule form, by injection, inhalation, eye lotion, ointment, suppository, etc. administration by injection, infusion or inhalation; topical by lotion or ointment; and rectal by suppositories. Oral administrations are preferred. [0178] The phrases “parenteral administration” and “administered parenterally” as used herein means modes of administration other than enteral and topical administration, usually by injection, and includes, without limitation, intravenous, intramuscular, intraarterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, transtracheal, subcutaneous, subcuticular, intraarticular, subcapsular, subarachnoid, intraspinal and intrasternal injection and infusion. [0179] The phrases “systemic administration,” “administered systemically,” “peripheral administration” and “administered peripherally” as used herein mean the administration of a compound, drug or other material other than directly into the central nervous system, such that it enters the patient’s system and, thus, is subject to metabolism and other like processes, for example, subcutaneous administration. [0180] These compounds may be administered to humans and other animals for therapy by any suitable route of administration, including orally, nasally, as by, for example, a spray, rectally, intravaginally, parenterally, intracisternally and topically, as by powders, ointments or drops, including buccally and sublingually. [0181] Regardless of the route of administration selected, the compounds of the present invention, which may be used in a suitable hydrated form, and/or the pharmaceutical compositions of the present invention, are formulated into pharmaceutically-acceptable dosage forms by conventional methods known to those of skill in the art. [0182] Actual dosage levels of the active ingredients in the pharmaceutical compositions of this invention may be varied so as to obtain an amount of the active ingredient which is effective to achieve the desired therapeutic response for a particular patient, composition, and mode of administration, without being toxic to the patient. [0183] The selected dosage level will depend upon a variety of factors including the activity of the particular compound of the present invention employed, or the ester, salt or amide thereof, the route of administration, the time of administration, the rate of excretion or metabolism of the particular compound being employed, the rate and extent of absorption, the duration of the treatment, other drugs, compounds and/or materials used in combination with the particular compound employed, the age, sex, weight, condition, general health and prior medical history of the patient being treated, and like factors well known in the medical arts. [0184] A physician or veterinarian having ordinary skill in the art can readily determine and prescribe the effective amount of the pharmaceutical composition required. For example, the physician or veterinarian could start doses of the compounds of the invention employed in the pharmaceutical composition at levels lower than that required in order to achieve the desired therapeutic effect and gradually increase the dosage until the desired effect is achieved. [0185] In general, a suitable daily dose of a compound of the invention will be that amount of the compound which is the lowest dose effective to produce a therapeutic effect. Such an effective dose will generally depend upon the factors described above. Preferably, the compounds are administered at about 0.01 mg/kg to about 200 mg/kg, more preferably at about 0.1 mg/kg to about 100 mg/kg, even more preferably at about 0.5 mg/kg to about 50 mg/kg. When the compounds described herein are co-administered with another agent (e.g., as sensitizing agents), the effective amount may be less than when the agent is used alone. [0186] If desired, the effective daily dose of the active compound may be administered as two, three, four, five, six or more sub-doses administered separately at appropriate intervals throughout the day, optionally, in unit dosage forms. Preferred dosing is one administration per day. [0187] The invention further provides a unit dosage form (such as a tablet or capsule) comprising an (aza)indazolyl-aryl sulfonamide or related compound described herein in a therapeutically effective amount for the treatment of a medical disorder described herein. EXAMPLES [0188] The representative examples that follow are intended to help illustrate the invention, and are not intended to, nor should they be construed to, limit the scope of the invention. [0189] The compounds provided herein can be prepared from readily available starting materials using the following general methods and procedures. It will be appreciated that where typical or preferred process conditions (i.e., reaction temperatures, times, mole ratios of reactants, solvents, pressures, etc.) are given, other process conditions can also be used unless otherwise stated. Optimal reaction conditions may vary with the particular reactants or solvent used, but such conditions can be determined by one skilled in the art by routine optimization. [0190] Additionally, as will be apparent to those skilled in the art, conventional protecting groups may be necessary to prevent certain functional groups from undergoing undesired reactions. The choice of a suitable protecting group for a particular functional group as well as suitable conditions for protection and deprotection are well known in the art. For example, numerous protecting groups, and their introduction and removal, are described in T. W. Greene and P. G. M. Wuts, Protecting Groups in Organic Synthesis, Second Edition, Wiley, New York, 1991, and references cited therein. [0191] The compounds provided herein may be isolated and purified by known standard procedures. Such procedures include recrystallization, filtration, flash chromatography, trituration, high pressure liquid chromatography (HPLC), or supercritical fluid chromatography (SFC). Note that flash chromatography may either be performed manually or via an automated system. The compounds provided herein may be characterized by known standard procedures, such as nuclear magnetic resonance spectroscopy (NMR) or liquid chromatography mass spectrometry (LCMS). NMR chemical shifts are reported in part per million (ppm) and are generated using methods well known to those of skill in the art. List of Abbreviations: Ac acetyl ACN acetonitrile AcOH acetic acid AIBN azobisisobutyronitrile BAST bis(2-methoxyethyl)aminosulfur trifluoride Boc tert-butyloxycarbonyl BINAP 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl BINOL 1,1′-bi-2-naphthol BPO benzoyl peroxide COD 1,5-cyclooctadiene Cy cyclohexyl CDI carbonyldiimidazole DAST diethylaminosulfur trifluoride dba dibenzylideneacetone DBU 1,8-diazabicyclo[5.4.0]undec-7-ene DCE dichloroethane DCM dichloromethane DDQ 2,3-dichloro-5,6-dicyano-1,4-benzoquinone DEAD diethyl azodicarboxylate DHP dihydropyran DIEA diisopropylethylamine DMA dimethylacetamide DMAP 4-dimethylaminopyridine DMF dimethylformamide DMSO dimethyl sulfoxide dppf 1,1'-bis(diphenylphosphino)ferrocene dtbbpy 4,4′-di-tert-butyl-2,2′-dipyridyl dtbpf 1,1’-bis(di-tert-butylphosphino)ferrocene EA ethyl acetate EDTA Ethylenediaminetetraacetic acid EtOAc ethyl acetate FA formic acid HATU 1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyri dinium-3-oxide hexafluorophosphate HMDS bis(trimethylsilyl)amide HPLC high performance liquid chromatography IBX 2-iodoxybenzoic acid IPA isopropyl alcohol LAH lithium aluminum hydride LCMS liquid chromatography-mass spectrometry LDA lithium diisopropylamide MeCN acetonitrile MTBE methyl tert-butyl ether NBS N-bromosuccinimide NCS N-chlorosuccinimide NIS N-iodosuccinimide NMI N-methylimidazole NMP N-methylpyrrolidinone NMR nuclear magnetic resonance spectroscopy PE petroleum ether Pin pinacolato PMB p-methoxybenzyl Py pyridine rt room temperature RT retention time SEM trimethylsilylethoxymethyl SFC super-critical fluid chromatography TBAB tetrabutylammonium bromide TBAF tetrabutylammonium fluoride TBDPS tert-butyldiphenylsilyl TBS tert-butyldimethylsilyl TCFH Chloro-N,N,N′,N′-tetramethylformamidinium hexafluorophosphate TEA triethylamine Tf triflate/trifluoromethanesulfonate TFA trifluoroacetic acid TFAA trifluoroacetic acid anhydride TMAD N,N,N',N'-Tetramethylazodicarboxamide TMS trimethylsilyl Ts tosyl General Schemes [0192] In some embodiments, compounds of the present disclosure may be manufactured using a process comprising one or more of Schemes 1-14 as set out below. Reaction steps represented by dashed arrows are to be understood to be optional. Unless otherwise specified, the variables of the Schemes are as defined herein. Reaction conditions should be understood to be exemplary and non-limiting, and may occur in the presence of an appropriate solvent. [0193] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 1, wherein Z is halide, R is alkyl, R ^a is alkyl, and R ^b is substituted or unsubstituted alkyl. Scheme 1 [0194] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 2, wherein Z is halide, R is alkyl, R ^a is alkyl, and R ^b is substituted or unsubstituted alkyl. Scheme 2 [0195] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 3, wherein Z is halide, R is alkyl, R ^a is methyl, and R ^b is substituted or unsubstituted alkyl. Scheme 3 [0196] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 4, wherein Z is halide, Y is amide or ester, and R is alkyl.

Scheme 4 [0197] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 5, wherein Z is halide, Y is amide or ester, and R is alkyl. Scheme 5 [0198] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 6, wherein Z is halide, R is alkyl, and R ^a is alkyl.

Scheme 6 [0199] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 7, wherein Z is halide, R is alkyl, and Hy is heterocycle or heteroaryl. Scheme 7 [0200] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 8, wherein Z is halide, R is alkyl, and Hy is heterocycle or heteroaryl. Scheme 8 [0201] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 9, wherein Z is halide, R is alkyl, and Hy is heterocycle or heteroaryl. Scheme 9 [0202] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 10, wherein Z is halide, R is alkyl, FG is a functional group that may be readily converted to a heterocycle or heteroaryl, and Hy is heterocycle or heteroaryl. In some embodiments, FG is cyano and may be reacted with, for example, an amino aldehyde acetal with base and/or acid, or an amidine reagent with base, to form a heterocycle or heteroaryl. In some embodiments, FG is halogen and may be reacted with a heterocyclyl or heteroaryl organolithium reagent and metal catalyst. Scheme 10 [0203] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 11, wherein Z is halide, R is alkyl, and Hy is heterocycle or heteroaryl. Scheme 11 [0204] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 12, wherein FG is a functional group that may be readily converted to a heterocycle or heteroaryl, and Hy is heterocycle or heteroaryl. In some embodiments, FG is cyano and may be reacted with, for example, an amino aldehyde acetal with base and/or acid, or an amidine reagent with base, to form a heterocycle or heteroaryl. In some embodiments, FG is halogen and may be reacted with a heterocyclyl or heteroaryl organolithium and metal catalyst. Scheme 12 [0205] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 13, wherein Hy is heterocycle or heteroaryl.

Scheme 13 [0206] In some embodiments, compounds of the present disclosure may be synthesized using a process comprising Scheme 14, wherein W is -NCH ₃ or -OCH ₃ , and R ^c is H or methyl. Scheme 14 Example 1: Synthesis of 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (Intermediate 1) Synthesis of Int.1-a: 3-(benzylsulfanyl)-5-fluoro-2-methoxypyridine [0207] Into a 2000 mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed 3-bromo-5-fluoro-2-methoxypyridine (150 g, 728 mmol, 1 equiv.), benzyl mercaptan (109 g, 878 mmol, 1.2 equiv), Pd ₂ (dba) ₃ (41.9 g, 36 mmol, 0.05 equiv.), Xantphos (30 g, 52 mmol, 0.07 equiv), DIEA (189 g, 1.46 mol) and toluene (1.2 L). The resulting solution was stirred for 2 h at 85 °C in an oil bath, then concentrated under vacuum. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:10) to give 3-(benzylsulfanyl)-5-fluoro-2-methoxypyridine (172 g, 95% yield) as a colorless oil. Synthesis of Int.1: 5-fluoro-2-methoxypyridine-3-sulfonyl chloride [0208] Into a 2000 mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed 3-(benzylsulfanyl)-5-fluoro-2-methoxypyridine (172 g, 690 mmol, 1 equiv.) and CH ₃ CN (1000 mL). This was followed by the addition of HCl (57 mL) at 10 °C. To this was added NCS (368.5 g, 2760 mmol, 4 equiv) in portions at 10 °C. The resulting solution was stirred for 30 min at 10~20 °C in a water/ice bath. The resulting solution was diluted with 2000 mL of H ₂ O and extracted with 2 x 1.5 L of dichloromethane. The combined organics were washed with 2000 ml of brine and dried over anhydrous sodium sulfate, before being concentrated. The residue was applied to a silica gel column which was eluted with PE.5-Fluoro-2-methoxypyridine-3-sulfonyl chloride (50.5 g, 32% yield) was isolated as a white solid. ¹ H-NMR: (300 MHz, Chloroform-d, ppm): δ 8.366 (d, J = 3.0 Hz, 1H), 8.043-8.011 (m, 1H), 4.178(s, 3H). Example 2: Synthesis of 5-chloro-2-methoxypyridine-3-sulfonyl chloride (Intermediate 2) Synthesis of Int.2-a: 3-(benzylsulfanyl)-5-chloro-2-methoxypyridine [0209] Into a 3000 mL round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed 3-bromo-5-chloro-2-methoxypyridine (150 g, 678 mmol, 1.0 equiv), toluene (1500 mL), phenylmethanethiol (92.6 g, 746 mmol, 1.1 equiv), DIEA (175.4 g, 1357 mmol, 2.0 equiv), XantPhos (3.9 g, 6 mmol, 0.01 equiv) and Pd ₂ (dba) ₃ -CHCl ₃ (5.3 g, 5 mmol 0.0075 equiv). The resulting solution was stirred for 4 h at 110 °C in an oil bath. The solids were removed by filtration and the filtrate concentrated. The residue was applied onto a silica gel column, eluting with PE: EA=20: 1. Concentration of the appropriate fractions gave a solid which was slurried with PE (3 V). The solid was removed by filtration and dried to give 3-(benzylsulfanyl)-5-chloro-2-methoxypyridine (130 g, 72% yield) as a yellow solid. Synthesis of Int.2: 5-chloro-2-methoxypyridine-3-sulfonyl chloride [0210] Into a 4000 mL round-bottom flask, was placed 3-(benzylsulfanyl)-5-chloro-2- methoxypyridine (130 g, 490 mmol, 1 equiv), MeCN (2600 mL, 20 V), H ₂ O (130 mL, 1 V), acetic acid (294 g, 491 mmol, 10 equiv) and NCS (196 g, 1471 mmol, 3.0 equiv). The resulting solution was stirred for 30 min at 25 °C. The reaction was quenched by the addition 1000 mL of water, and extracted with 2 x 1000 mL of ethyl acetate. The combined organics were washed with H ₂ O and concentrated. The resulting solution was diluted with 500 mL of diethyl ether and the solids removed by filtration. The filtrate was concentrated, and the residue purified by silica gel column chromatography, eluting with PE/THF (100:1). The concentrated product was slurried with 300 mL hexane and kept at 0 °C for 1 h. The solids were removed by filtration and dried to give 5-chloro-2-methoxypyridine-3-sulfonyl chloride (66.5 g, 56% yield) as a white solid. ¹ H-NMR: (300 MHz, CDCl ₃ , ppm): δ 8.45 (d, J = 2.5 Hz, 1H), 8.23 (d, J = 2.6 Hz, 1H), 4.21 (s, 3H). Example 3 : Synthesis of 5-cyano-2-methoxypyridine-3-sulfonyl chloride (Intermediate 3) Synthesis of Int.3-a: 5-bromo-6-methoxypyridine-3-carbonitrile [0211] Into a 2 L round-bottom flask were added 6-methoxypyridine-3-carbonitrile (100 g, 746 mmol, 1 equiv), HOAc (1000 mL), NaOAc (61 g, 746 mmol, 1 equiv) and Br2 (235 g, 1490 mmol, 2 equiv) at room temperature. The resulting mixture was stirred for 48 h at 80 °C. The mixture was allowed to cool to room temperature and was diluted with ice water (3 L). The precipitated solids were collected by filtration and suspended in 1 L of PE:EA=5:1 which was stirred for 1 h at room temperature. The precipitated solids were collected by filtration and dried to give 5-bromo-6-methoxypyridine-3-carbonitrile (70 g, 44% yield) as a light yellow solid. Synthesis of Int.3-b: 5-(benzylsulfanyl)-6-methoxypyridine-3-carbonitrile [0212] Into a 3 L 3-necked round-bottom flask, were added 5-bromo-6-methoxypyridine-3- carbonitrile (70 g, 330 mmol, 1 equiv), toluene (1400 mL) and benzyl mercaptan (43 g, 347 mmol, 1.05 equiv) at room temperature. To this was added Pd ₂ (dba) ₃ .CHCl ₃ (17 g, 16.5 mmol, 0.05 equiv), Xantphos (19 g, 33 mmol, 0.1 equiv) and DIEA (128 g, 990 mmol, 3 equiv) under nitrogen atmosphere. The resulting mixture was stirred for 3 h at 90 °C under nitrogen atmosphere, then was cooled and filtered. The filtrate was concentrated under reduced pressure, and the residue purified by silica gel column chromatography, eluting with PE/THF (10:1).5-(Benzylsulfanyl)-6-methoxypyridine-3-carbonitrile (65 g, 77% yield) was obtained as a light brown solid. Synthesis of Int.3: 5-cyano-2-methoxypyridine-3-sulfonyl chloride [0213] Into a 2 L 3-necked round-bottom flask were added 5-(benzylsulfanyl)-6- methoxypyridine-3-carbonitrile (65 g, 2540 mmol, 1 equiv), MeCN (520 g), H ₂ O (260 g) and HCl (21 mL, 254 mmol, 1 equiv) at room temperature. To this was added NCS (101 g, 762 mmol, 3 equiv) in portions at 0 °C. The resulting mixture was stirred for 0.5 h at room temperature, then was cooled to 0 °C and stirred for 1 h. The precipitated solids were collected by filtration and dried to afford 5-cyano-2-methoxypyridine-3-sulfonyl chloride (25 g, 42% yield) as a white solid. H-NMR: (300 MHz, CDCl3, ppm): δ 8.78 (d, J = 2.2 Hz, 1H), 8.51 (d, J = 2.2 Hz, 1H), 4.31 (s, 3H).

Example 4: Synthesis of 5-fluoro-2-methylpyridine-3-sulfonyl chloride (Intermediate 4) Synthesis of Int.4-a: tert-butyl N-(2-bromo-5-fluoropyridin-3-yl)-N-(tert- butoxycarbonyl)carbamate [0214] Into a 500 mL 3-necked round-bottom flask was placed 2-bromo-5-fluoropyridin-3- amine (20 g, 1 equiv), DCM (220 mL) and TEA (44 mL, 3 equiv). This was followed by the addition of Boc ₂ O (57 g, 2.5 equiv) in several batches at 26 °C. The resulting solution was stirred for 14 h at 26 °C. The reaction mixture was concentrated, and the residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:5). This resulted in tert- butyl N-(2-bromo-5-fluoropyridin-3-yl)-N-(tert-butoxycarbonyl)carb amate (33 g) as a white solid. Synthesis of Int.4-b: tert-butyl N-(tert-butoxycarbonyl)-N-(5-fluoro-2-methylpyridin-3- yl)carbamate [0215] Into a 500 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed tert-butyl N-(2-bromo-5-fluoropyridin-3-yl)-N-(tert- butoxycarbonyl)carbamate (33 g, 84 mmol, 1 equiv), 1,4-dioxane (150 mL), trimethyl- 1,3,5,2,4,6-trioxatriborinane (21.2 g, 169 mmol, 2 equiv), K ₂ CO ₃ (35 g, 253 mmol, 3 equiv) and Pd(dppf)Cl ₂ (3.09 g, 4.2 mmol, 0.05 equiv). The resulting solution was stirred overnight at 110 °C under N ₂ atmosphere. The reaction mixture was cooled to room temperature and filtered. The filtrate was diluted with 200 mL of H ₂ O and extracted with 3 x 100 mL of ethyl acetate. The combined organics were concentrated and the residue applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:10-1:5). Tert-butyl N-(tert- butoxycarbonyl)-N-(5-fluoro-2-methylpyridin-3-yl)carbamate (16 g, 58% yield) was isolated as a yellow solid. Synthesis of Int.4-c: 3-bromo-5-fluoro-2-methylpyridine [0216] Into a 2 L 3-necked round-bottom flask, was placed tert-butyl N-(tert- butoxycarbonyl)-N-(5-fluoro-2-methylpyridin-3-yl)carbamate (50 g, 153 mmol, 1 equiv) and HBr (1 L, 48%) . This was followed by the addition of a solution of NaNO ₂ (11.6 g, 169 mmol, 1.1 equiv) in H ₂ O (100 mL) dropwise with stirring at 0-5 °C. The resulting solution was stirred for 30 min in an ice bath. To this was added CuBr (24.2 g, 169 mmol, 1.1 equiv) at 0 °C. The resulting solution was stirred for 1 h at room temperature, then quenched by the addition of 1 L water/ice. The pH of the solution was adjusted to 8 with Na ₂ CO ₃ and the resulting mixture was extracted with 3x200 mL of ethyl acetate. The combined organics were dried over anhydrous sodium sulfate and concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:50). 3-Bromo-5-fluoro-2- methylpyridine (13 g, 45% yield) was isolated as a white solid. Synthesis of Int.4-d: 3-(benzylsulfanyl)-5-fluoro-2-methylpyridine [0217] Into a 250 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 3-bromo-5-fluoro-2-methylpyridine (13 g, 68 mmol, 1 equiv), toluene (130 mL), benzyl mercaptan (12.8 g, 103 mmol, 1.5 equiv), DIEA (17.7 g, 137 mmol, 2 equiv), XantPhos (3.96 g, 6.8 mmol, 0.1 equiv) and Pd ₂ (dba) ₃ (3.13 g, 3.4 mmol, 0.05 equiv). The resulting solution was stirred for 4 h at 115 °C, then cooled and concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:20) to give 3-(benzylsulfanyl)-5-fluoro-2-methylpyridine (11 g, 69% yield) as a yellow solid. Synthesis of Int.4: 5-fluoro-2-methylpyridine-3-sulfonyl chloride [0218] Into a 2000 mL 3-necked round-bottom flask, was placed 3-(benzylsulfanyl)-5-fluoro- 2-methylpyridine (45 g, 193 mmol, 1 equiv), HOAc (700 mL) and H ₂ O (200 mL). This was followed by the addition of NCS (103 g, 772 mmol, 4 equiv), the temperature being maintained under 20 °C. The resulting solution was stirred for 2 h at room temperature. The reaction was quenched by the addition of 700 mL of water, and the resulting solution was extracted with 3 x 300 mL of dichloromethane. The combined organics were concentrated, and the residue applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:10). 5-Fluoro-2-methylpyridine-3-sulfonyl chloride (25.4 g, 63% yield) was obtained as a yellow oil. LCMS: (ES, m/z): [M+1] ⁺ =210 ¹ H-NMR: (300 MHz, CDCl ₃ , ppm): δ 8.72-8.71 (d, J = 3.0 Hz, 1H), 8.11-8.08 (dd, J = 3.0 Hz, 1H), 3.01 (s, 3H). Example 5: Synthesis of 5-chloro-N-[3,5-difluoro-4-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]pyridin-2-yl]-2-methoxypyridine-3-sulfonamide (Intermediate 5) Synthesis of Intermediate 5: N-(3-bromo-2,4-difluorophenyl)-5-chloro-2-methoxypyridine-3- sulfonamide [0219] To a solution of 3-bromo-2,4-difluoroaniline (5 g, 24 mmol, 1 eq ) in DCM (100 mL) were added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (8.73 g, 36 mmol, 1.5 eq ) and pyridine (5.7 g, 72 mmol, 3 eq ). The resulting solution was stirred for 1 hour at room temperature. The reaction was concentrated and purified by column chromatography over silica gel (eluent: PE:EA =8:1) to afford N-(3-bromo-2,4-difluorophenyl)-5-chloro-2- methoxypyridine-3-sulfonamide (7 g, 70% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 412 ¹ H NMR (300 MHz, Chloroform-d) δ 8.30 (d, J = 2.6 Hz, 1H), 8.05 (d, J = 2.6 Hz, 1H), 7.56 (td, J = 8.9, 5.4 Hz, 1H), 7.28 (d, J = 3.4 Hz, 1H), 6.96 (ddd, J = 9.4, 7.6, 2.1 Hz, 1H), 4.16 (s, 3H). Example 6: Synthesis of ethyl 6-bromoimidazo[1,5-a]pyridine-1-carboxylate (Intermediate 6) Synthesis of Int.6-a ethyl 2-(5-bromopyridin-2-yl)acetate [0220] Into a 250 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed a solution of 5-bromo-2-methylpyridine (3 g, 17 mmol, 1 equiv) in THF (100 mL). This was followed by the addition of LiHMDS in THF (34 mL, 34 mmol, 2 equiv) dropwise with stirring at 0 °C over 30 min. To this was added diethyl carbonate (3.1 g, 26 mmol, 1.5 equiv) at 0 °C and the resulting solution was stirred for 5 h at room temperature. The reaction was quenched by the addition of 30 mL of H ₂ O, and the resulting mixture was concentrated under vacuum. The residue was diluted with 100 mL of EA, and the organics washed with H ₂ O (2 x 100 mL) and brine (100 mL). After drying over anhydrous sodium sulfate, the solution was concentrated under vacuum to give ethyl 2-(5- bromopyridin-2-yl)acetate (3.0 g crude) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 244 Synthesis of Int.6-b: ethyl 2-(5-bromopyridin-2-yl)-2-(N-hydroxyimino)acetate [0221] Into a 25 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed a solution of ethyl 2-(5-bromopyridin-2-yl)acetate (2.9 g, 12 mmol, 1 equiv) in AcOH (5 mL). This was followed by the addition of a solution of NaNO ₂ (823 mg, 12 mmol, 1 equiv) in H ₂ O (2 mL) dropwise with stirring at 0 °C. The resulting solution was stirred for 1 hr at room temperature, then diluted with 20 mL of H ₂ O. The mixture was extracted with 2x20 mL of ethyl acetate and the combined organics washed with 30 ml of brine, then dried over anhydrous sodium sulfate. Concentration gave ethyl 2-(5- bromopyridin-2-yl)-2-(N-hydroxyimino)acetate (2.3 g) as a yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 273 Synthesis of Int.6-c: ethyl 2-amino-2-(5-bromopyridin-2-yl)acetate [0222] Into a 100 mL 3-necked round-bottom flask, was placed a solution of ethyl 2-(5- bromopyridin-2-yl)-2-(N-hydroxyimino)acetate (2.3 g, 8.3 mmol, 1 equiv) in AcOH (20 mL). This was followed by the addition of Zn (1.6 g, 25 mmol, 3 equiv) in portions at 0 °C over 10 min. The resulting solution was stirred for 60 min at room temperature. The solids were removed by filtration and the filtrate concentrated under vacuum to give crude ethyl 2-amino- 2-(5-bromopyridin-2-yl)acetate (1.8 g) as a yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 259 Synthesis of Intermediate 6: ethyl 6-bromoimidazo[1,5-a]pyridine-1-carboxylate [0223] Into a 5 mL microwave tube, was placed ethyl 2-amino-2-(5-bromopyridin-2- yl)acetate (1.8 g, 7 mmol, 1 equiv) and triethyl orthoformate (3 mL). The resulting solution was stirred for 10 min at 130 °C, then was cooled and concentrated. The residue was applied to a silica gel column, eluting with THF/PE (1:1). Ethyl 6-bromoimidazo[1,5-a]pyridine-1- carboxylate (530 mg) was isolated as a purple solid. LCMS (ES, m/z): [M+H] ⁺ : 269

Example 7: Synthesis of 6-bromo-1-iodoimidazo[1,5-a]pyridine (Intermediate 7) Synthesis of Int.7-a (E)-N-[(5-bromopyridin-2-yl)methylidene]hydroxylamine [0224] Into a 500 mL 3-necked round-bottom flask was placed a solution of 5- bromopyridine-2-carbaldehyde (20 g, 0.11 mol, 1 equiv) in MeOH (150 mL), followed by a solution of Na ₂ CO ₃ (23 g, 0.2 mol, 2 equiv) in H ₂ O (100 mL). Hydroxylamine hydrochloride (9.7 g, 0.14 mol, 1.3 equiv) was then added at 0°C. The resulting solution was stirred for 2 hr at 60 °C in an oil bath. The reaction was quenched by the addition of 500 mL of water/ice, and the solids were collected by filtration. Air drying yielded (E)-N-[(5-bromopyridin-2- yl)methylidene]hydroxylamine (21 g, 87% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 201 Synthesis of Int.7-b: 1-(5-bromopyridin-2-yl)methanamine [0225] Into a 500 mL 3-necked round-bottom flask was placed (E)-N-[(5-bromopyridin-2- yl)methylidene]hydroxylamine (21 g, 0.1 mol, 1 equiv) and AcOH (200 mL). Zn (20.5 g, 0.3 mol, 3 equiv) was then added in portions at 0-10 °C. The resulting solution was stirred for 30 min at 0~10 °C in an ice/salt bath. The solids were filtered out and the filtrate concentrated under vacuum. The resulting mixture was diluted with 200 mL of H ₂ O, and the pH adjusted to 10 with ammonia. The resulting solution was extracted with 6 x 150 mL of DCM:MeOH (10:1) and the organic layers combined and dried over anhydrous sodium sulfate. Concentration resulted in 1-(5-bromopyridin-2-yl)methanamine (18 g, 92% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 187 Synthesis of Int.7-c: N-[(5-bromopyridin-2-yl)methyl]formamide [0226] Into a 500 mL 3-necked round-bottom flask was placed 1-(5-bromopyridin-2- yl)methanamine (18 g, 97 mmol, 1 equiv) and formic acid (150 mL). The resulting solution was stirred for 3 h at 100 °C in an oil bath, then cooled and diluted with 500 mL of H ₂ O. The resulting solution was extracted with 2x300 mL of ethyl acetate and the organic layers combined. The resulting solution was washed with 500 ml of brine, dried over anhydrous sodium sulphate and concentrated under vacuum. This resulted in N-[(5-bromopyridin-2- yl)methyl]formamide (13 g) as a crude brown solid. LCMS (ES, m/z): [M+H] ⁺ : 215 Synthesis of Int.7-d: 6-bromoimidazo[1,5-a]pyridine [0227] Into a 500 mL 3-necked round-bottom flask was placed N-[(5-bromopyridin-2- yl)methyl]formamide (13 g, 61 mmol, 1 equiv), toluene (150 mL) and POCl ₃ (46.4 g, 305 mmol, 5 equiv). The resulting solution was stirred for 2 h at 100 °C, then cooled and concentrated under vacuum. The residue was carefully diluted with 150 mL of H ₂ O and the pH adjusted to 10 with ammonia. The resulting solution was extracted with 3 x 150 mL of dichloromethane and the organic layers combined. The solution was washed with 300 ml of brine, dried over anhydrous sodium sulfate and concentrated under vacuum to give 6- bromoimidazo[1,5-a]pyridine (10.5 g, 79% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 197 Synthesis of Intermediate 7: 6-bromo-1-iodoimidazo[1,5-a]pyridine [0228] Into a 250 mL 3-necked round-bottom flask was placed 6-bromoimidazo[1,5- a]pyridine (10.5 g, 53.5 mmol, 1 equiv) in DMF (100 mL). This was followed by the addition of NIS (12 g, 53.5 mmol, 1 equiv) at 0 °C. The resulting solution was stirred for 60 min at 0 °C in an ice/salt bath, then quenched by the addition of 200 mL of saturated Na ₂ S ₂ O ₃ /H ₂ O. The solids were collected by filtration and dried to give 6-bromo-1-iodoimidazo[1,5- a]pyridine (12.8 g, 67% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 323 Example 8: Synthesis of 6-bromo-1-iodoimidazo[1,5-a]pyridine (Intermediate 8) Synthesis of Int.8-a: Ethyl 3-(4-bromo-2-fluorophenyl)propanoate [0229] Into a 500 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 4-bromo-2-fluoro-1-iodobenzene (20 g, 67 mmol, 1 equiv), DMF (200 mL), 3,3-diethoxy-1-propene (11.3 g, 86 mmol, 1.3 equiv), tetrabutylammonium chloride (18.5 g, 67 mmol, 1 equiv), DIEA (23 g, 179 mmol, 2.7 equiv) and Pd(AcO)2 (750 mg, 3 mmol, 0.05 equiv). The resulting solution was stirred for 2 h at 90 °C in an oil bath. The reaction mixture was cooled to 25 °C with a water/ice bath and the solution was diluted with 600 mL of H ₂ O. The resulting mixture was extracted with 2x 200 mL of ethyl acetate and the organic layers combined. The organics were washed with 100 mL of brine. The mixture was dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column, eluting with PE/EA=95/5. Ethyl 3- (4-bromo-2-fluorophenyl)propanoate (14.5 g, 50% yield) was isolated as a light yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 275. Synthesis of Int.8-b: 3-(4-bromo-2-fluorophenyl)propanoic acid [0230] Into a 1000 mL round-bottom flask, was placed ethyl 3-(4-bromo-2- fluorophenyl)propanoate (16.5 g, 60 mmol, 1 equiv), THF (120 mL), MeOH (120 mL) and 4N aqueous NaOH (120 mL, 480 mmol). The resulting solution was stirred for 2 h at 50 °C in an oil bath. The reaction mixture was concentrated under vacuum and the residue extracted with 2x100 mL of ethyl acetate. The pH of the aqueous layer was acidified with 4N HCl. The resulting suspension was extracted with 3x100 mL of ethyl acetate and the organic layers combined. The organics were washed with 100 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column, eluting with 0-40% EA/PE.3-(4-Bromo-2-fluorophenyl) propanoic acid (11.5 g, 78% yield) was isolated as a white solid. Synthesis of Int.8-c: 6-bromo-4-fluoro-2,3-dihydro-1H-inden-1-one [0231] To a stirred mixture of 3-(4-bromo-2-fluorophenyl)propanoic acid (11.5 g, 47 mmol, 1 equiv) in DCM (200mL) was added oxalyl chloride (11.8 g, 93 mmol, 2 equiv) dropwise at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 4 h then concentrated under reduced pressure. The residue was dissolved in DCM (200 mL). To the above mixture was added AlCl ₃ (18.6 g, 140 mmol, 3 equiv) in portions at room temperature. The resulting mixture was stirred for additional 3h at 40 °C. Further AlCl ₃ (18.6 g, 140 mmol, 3 equiv) was added in portions. The resulting mixture was stirred overnight at 40 °C. The reaction mixture was diluted with NH ₄ Cl (300 mL) and extracted with CH ₂ Cl ₂ (3 x 200 mL). The combined organic layers were washed with brine (100 mL) and dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography with EA/PE=1/2 to afford 6-bromo-4- fluoro-2,3-dihydroinden-1-one (6.5 g, 61% yield) as a white solid. Synthesis of Int.8-d: 7-fluoro-3-oxo-2,3-dihydro-1H-indene-5-carbonitrile [0232] Into a 100 mL round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 6-bromo-4-fluoro-2,3-dihydroinden-1-one (4.6 g, 20.1 mmol, 1 equiv), NMP (50 mL) and Cu(CN) ₂ (4.7 g, 40 mmol, 2 equiv). The resulting solution was stirred overnight at 175 °C. The cooled reaction mixture was diluted with 200 mL of H ₂ O and extracted with 3x50 mL of ethyl acetate. The combined extracts were washed with 100 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column, eluting with 50-70% THF/PE.7-Fluoro-3-oxo-1,2- dihydroindene-5-carbonitrile (1.5 g, 43% yield) was isolated as a light yellow solid. Synthesis of Int.8-e: 7-(benzylthio)-3-oxo-2,3-dihydro-1H-indene-5-carbonitrile [0233] Into a 4 mL vial was added 7-fluoro-3-oxo-1,2-dihydroindene-5-carbonitrile (450 mg, 2.6 mmol, 1 equiv) and ACN (15 mL) at room temperature. To the stirred solution was added Cs ₂ CO ₃ (920 mg, 2.8 mmol, 1.1 equiv) and benzyl mercaptan (478 mg, 3.9 mmol, 1.5 equiv) at room temperature. The resulting mixture was stirred overnight at room temperature. The reaction mixture was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with CH ₂ Cl ₂ / MeOH (9:1) to afford 7-(benzylsulfanyl)- 3-oxo-1,2-dihydroindene-5-carbonitrile (550 mg, 77% yield) as a white solid. Synthesis of Int.8-f: 7-(benzylsulfanyl)-3-hydroxy-2,3-dihydro-1H-indene-5-carboni trile [0234] Into a 100 mL round-bottom flask were added 7-(benzylsulfanyl)-3-oxo-1,2- dihydroindene-5-carbonitrile (550 mg, 2 mmol, 1 equiv) and MeOH (15 mL). To the solution was added NaBH ₄ (97 mg, 2.6 mmol, 1.3 equiv) at room temperature. The resulting mixture was stirred for 1 h at room temperature, then diluted with water (50 mL). The resulting mixture was extracted with EtOAc (3x50 mL). The combined organic layers were washed with brine (30 mL) and dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with CH ₂ Cl ₂ / MeOH (9:1) to afford 7-(benzylsulfanyl)-3-hydroxy- 2,3-dihydro-1H-indene-5-carbonitrile (560 mg, crude) as a light grey solid. Synthesis of Int.8-g: 4-(benzylsulfanyl)-6-cyano-2,3-dihydro-1H-inden-1-yl acetate [0235] Into a 2 mL vial were added 7-(benzylsulfanyl)-3-hydroxy-2,3-dihydro-1H-indene-5- carbonitrile (400 mg, 1.4 mmol, 1 equiv) and DCM (10 mL). To the stirred solution was added TEA (288 mg, 2.8 mmol, 2 equiv) and acetyl chloride (167 mg, 2.1 mmol, 1.5 equiv) dropwise at room temperature under nitrogen atmosphere. The reaction mixture was stirred for 1.5 h at room temperature, then quenched by the addition of MeOH (5 mL). The resulting mixture was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (8:1) to afford 4-(benzylsulfanyl)-6-cyano- 2,3-dihydro-1H-inden-1-yl acetate (360 mg, 78% yield) as a white solid. Synthesis of Intermediate 8: 4-(chlorosulfonyl)-6-cyano-2,3-dihydro-1H-inden-1-yl acetate [0236] Into a 20 mL vial were added 4-(benzylsulfanyl)-6-cyano-2,3-dihydro-1H-inden-1-yl acetate (400 mg, 1.2 mmol, 1 equiv) and MeCN (4 mL). To the stirred mixture was added 1M HCl (1.2 mL, 33 mmol, 32 equiv) and NCS (661 mg, 4.8 mmol, 4 equiv) in portions. The resulting mixture was diluted with water (10 mL) when the reaction was shown to be complete. The resulting mixture was extracted with EtOAc (3 x10 mL). The combined organic layers were washed with brine (5 mL) and dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure. The crude product was used in the next step directly without further purification. Example 9: Synthesis of ethyl 2-bromoimidazo[1,5-b]pyridazine-5-carboxylate (Intermediate 9) Synthesis of Int.9: ethyl 2-bromoimidazo[1,5-b]pyridazine-5-carboxylate [0237] Into a 10 L 3-necked round-bottom flask, was placed a solution of ethyl 2- chloroimidazo[1,5- b]pyridazine-5-carboxylate (500 g, 2200 mmol, 1 equiv) in AcOH (5 L) and PBr ₃ (1800 g, 6650 mmol, 3 equiv). The resulting solution was stirred overnight at 100 °C, then quenched by the addition of water/ice. The resulting solution was extracted with ethyl acetate (3x2 L and the combined organic layers were treated with ammonia until the pH was 8. The resulting mixture was washed with brine (5 L), then concentrated to give ethyl 2- bromoimidazo[1,5-b]pyridazine-5-carboxylate (351 g, 59% yield) as a yellow solid. LC-MS: (ES, m/z): [M+H] ⁺ : 270 1H NMR (400 MHz, DMSO-d ₆ , ppm): δ 8.85 (s, 1H), 8.34 (d, J = 9.5 Hz, 1H), 7.36 (d, J = 9.5 Hz, 1H), 4.35 (q, J = 7.1 Hz, 2H), 1.35 (t, J = 7.1 Hz, 3H). Example 10: Synthesis of 3-cyano-5-(trifluoromethyl)benzenesulfonyl chloride (Intermediate 10) CN Synthesis of Int.10-a: 3-(benzylsulfanyl)-5- (trifluoromethyl)benzonitrile [0238] Into a 250 mL round-bottom flask, was placed 3-fluoro-5- (trifluoromethyl)benzonitrile (2 g, 10 mmol, 1 equiv), DMF (50 mL), LiOH (0.5 g, 21 mmol, 2 equiv) and benzyl mercaptan (1.6 g, 13 mmol, 1.2 equiv). The resulting solution was stirred for 1 h at 25 °C, then quenched by the addition of 100 mL of water. The resulting solution was extracted with 2x100 mL of ethyl acetate, and the combined organics washed with 3x100 mL of water. The organics were dried over anhydrous sodium sulfate and concentrated, to give 3-(benzylsulfanyl)-5- (trifluoromethyl)benzonitrile (3 g, 97% yield) as a yellow oil, which was used in next step directly without further purification. Synthesis of Intermediate 10: 3-cyano-5- (trifluoromethyl)benzenesulfonyl chloride [0239] Into a 40 mL vial, was placed MeCN (7.5 mL) and HCl (aqueous, 6M) (1.5 mL). This was followed by the addition of NCS (910 mg, 6.8 mmol, 4 equiv), in portions at 0°C. To this was added 3-(benzylsulfanyl)-5-(trifluoromethyl)benzonitrile (500 mg, 1.7 mmol, 1 equiv), in portions at 0°C. The resulting solution was stirred for 1 h in a water/ice bath. The reaction was quenched by the addition of 20 mL of water/ice and the resulting solution extracted with 2x20 mL of dichloromethane. The combined organics were washed with 2x20 mL of water, dried over anhydrous sodium sulfate and concentrated. This resulted in 3-cyano-5- (trifluoromethyl)benzenesulfonyl chloride (300 mg) as a crude yellow oil which was used in next step directly without further purification. Example 11: Synthesis of 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1- carboxylic acid & 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyrazin-6-yl]aniline (Intermediate 11 and Intermediate 12) Synthesis of Int.11-a: 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1-carbo xylate [0240] To a solution of ethyl 6-bromoimidazo[1,5-a]pyrazine-1-carboxylate (120 g, 444 mmol, 1 equiv) and 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) aniline (170 g, 666 mmol, 1.5 equiv) in dioxane (1 L) and H ₂ O ( 200 mL ) were added K ₃ PO ₄ (189 g, 889 mmol, 2 equiv) and Pd(dtbpf)Cl ₂ (29 g, 44 mmol, 0.1 equiv). After stirring for 3 h at 90°C under nitrogen, the resulting mixture was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (5:1) to afford ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1-carbo xylate (110 g, 78% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 319 Synthesis of Intermediate 11: 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1- carboxylic acid [0241] To a stirred solution of ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine- 1-carboxylate (110 g, 345 mmol, 1 equiv) in MeOH (500 mL), H ₂ O (500 mL) and THF (500 mL), was added LiOH (25 g, 1040 mmol, 3 equiv) in portions at room temperature. The resulting mixture was stirred for 1h then concentrated under vacuum. The resulting mixture was diluted with water (100mL) and acidified to pH 3 with HCl (aq.). The precipitated solids were collected by filtration and washed with water (3x50 mL). Drying gave 6-(3-amino-2,6- difluorophenyl)imidazo[1,5-a]pyrazine-1-carboxylic acid (100 g, 99% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 291 Synthesis of Int.12-a: 2,4-difluoro-3-[imidazo[1,5-a]pyrazin-6-yl]aniline [0242] Into a 2 L sealed tube were added 6-(3-amino-2,6-difluorophenyl)imidazo[1,5- a]pyrazine-1-carboxylic acid (100 g, 344 mmol, 1 equiv) and NMP (1.5 L) at room temperature. The resulting mixture was stirred for 3 h at 200°C. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 2,4-difluoro-3- [imidazo[1,5-a]pyrazin-6-yl]aniline (50 g, 59% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 247 Synthesis of Intermediate 12: 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyrazin-6-yl]aniline [0243] To a stirred solution of 2,4-difluoro-3-[imidazo[1,5-a]pyrazin-6-yl]aniline (50 g, 203 mmol, 1 equiv) in DMF (1 L) was added NIS (54.8 g, 243 mmol, 1.2 equiv) in portions. The reaction was stirred for 3 h then quenched by the addition of water (500 mL). The resulting mixture was extracted with EtOAc (3 x 200 mL). The combined organics were washed with brine (2 x 500 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyrazin-6-yl]aniline (35 g, 46% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 373 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.90 (d, J = 1.6 Hz, 1H), 8.63 (d, J = 0.7 Hz, 1H), 8.55 (s, 1H), 7.00-6.78 (m, 2H), 5.14 (s, 2H). Example 12: Synthesis of methyl 6-bromoimidazo[1,5-a]pyridine-1-carboxylate (Intermediate 13) Synthesis of Intermediate 13: methyl 6-bromoimidazo[1,5-a]pyridine-1-carboxylate [0244] To a stirred mixture of 5-bromo-2-fluoropyridine (130 g, 739 mmol, 1 equiv) and methyl 2-isocyanoacetate (88 g, 886 mmol, 1.2 equiv) in DMF (4 L) was added t-BuOK (887 mL, 1.2 equiv, 1 mol/L in THF ) dropwise at 0°C under nitrogen atmosphere. The mixture was stirred for 3 h, then was poured into water/ice (1L) and the resulting mixture extracted with CH ₂ Cl ₂ (4 x1L). The combined organics were washed with brine (2x1L), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford methyl 6- bromoimidazo[1,5-a]pyridine-1-carboxylate (60 g, 32% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 255, 257 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.90 (dd, J = 1.7, 1.0 Hz, 1H), 8.45- 8.39 (m, 1H), 7.92 (dt, J = 9.6, 0.9 Hz, 1H), 7.33 (dd, J = 9.6, 1.7 Hz, 1H), 3.84 (s, 3H). Example 13: Synthesis of methyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine- 1-carboxylate (Intermediate 14) Synthesis of Intermediate 14: methyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine- 1-carboxylate [0245] Into a 1 L 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed methyl 6-bromoimidazo[1,5-a]pyridine-1-carboxylate (40 g, 157 mmol, 1 equiv), bis(pinacolato)diboron (47.8 g, 188 mmol, 1.2 equiv), dioxane (500 mL), KOAc (31 g, 314 mmol, 2 equiv) and Pd(dppf)Cl ₂ (11.5 g, 16 mmol, 0.1 equiv) at room temperature. The resulting solution was stirred for 1 h at 90°C under nitrogen atmosphere. The reaction mixture was cooled to room temperature and H ₂ O (100 mL), K ₂ CO ₃ (43 g, 311 mmol, 2 equiv), 3-bromo-2,4-difluoroaniline (48.5 g, 233 mmol, 1.5 equiv) and Pd(dppf)Cl ₂ (11.4 g, 15.6 mmol, 0.1 equiv) were added. The resulting mixture was stirred for 1 h at 80°C under nitrogen atmosphere, then concentrated under reduced pressure. The residue was applied onto a silica gel column, eluting with ethyl acetate/petroleum ether (4:1) to afford methyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine-1-carbo xylate (32 g, 68% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 304 Example 14: Synthesis of ethyl 6-bromoimidazo[1,5-a]pyrazine-1-carboxylate (Intermediate 15) Synthesis of Int.15-a: ethyl 2-(5-bromopyrazin-2-yl)-2-[(diphenylmethylidene)amino]acetat e [0246] Into a 50 L 4-necked round-bottom flask was placed a solution of 2,5- dibromopyrazine (1.3 kg, 5465 mmol, 1 equiv) in NMP (25 L), K ₂ CO ₃ (1522 g, 10930 mmol, 2 equiv), ethyl 2-[(diphenylmethylidene)amino]acetate (1534 g, 5738 mmol, 1.05 equiv) and tetrabutylammonium bromide (1762 g, 5465 mmol, 1 equiv). The resulting solution was stirred for 10 h at 100°C. The reaction was cooled and quenched by the addition of 20 L of water/ice. The resulting solution was extracted with 3x15 L of ethyl acetate and the organic layers combined. The resulting mixture was washed with 1x10 L of brine, then concentrated under vacuum. This resulted in crude ethyl 2-(5-bromopyrazin-2-yl)-2- [(diphenylmethylidene)amino]acetate (2710 g) as a brown solid. LC-MS: (ES, m/z): [M+H] 424 Synthesis of Int.15-b: ethyl 2-amino-2-(5-bromopyrazin-2-yl)acetate [0247] Into a 50 L 4-necked round-bottom flask was placed a solution of ethyl 2-(5- bromopyrazin-2-yl)-2-[(diphenylmethylidene)amino]acetate (2500 g, purity 60%) in THF (10 L) and HCl (1 M, 10 L). The resulting solution was stirred for 30 min at 10 °C. The reaction was washed with dichloromethane (2x20 L), and the pH adjusted to 8 with NH ₄ OH. The resulting solution was extracted with 3x15 L of dichloromethane and the organic layers combined. The organics were washed with 10 L of brine and concentrated under vacuum. Crude ethyl 2-amino-2-(5-bromopyrazin-2-yl)acetate (1000 g) was obtained as a yellow solid. LC-MS: (ES, m/z): [M+H] 260 Synthesis of Intermediate 15: ethyl 6-bromoimidazo[1,5-a]pyrazine-1-carboxylate [0248] Into a 10 L 4-necked round-bottom flask was placed ethyl 2-amino-2-(5- bromopyrazin-2-yl)acetate (1 kg, 3076 mmol, 1 equiv, 80%) and triethyl orthoformate (5 L). The resulting solution was stirred for 1 h at 80°C, then cooled to 0°C with a water/ice bath. The solids were collected by filtration and dried to give ethyl 6-bromoimidazo[1,5- a]pyrazine-1-carboxylate (351 g, 42% yield) as a pink solid. LCMS (ES, m/z): [M+H] 270 ¹ H NMR : (300 MHz, DMSO-d ₆ , ppm): δ 9.21 (dd, J = 1.6, 0.6 Hz, 1H), 8.87 (d, J = 1.5 Hz, 1H), 8.57 (d, J = 0.6 Hz, 1H), 4.36 (q, J = 7.1 Hz, 2H), 1.35 (t, J = 7.1 Hz, 3H). Example 15: Synthesis of ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine-1- carboxylate (Intermediate 16) Synthesis of Int.16-a: ethyl 2-(5-bromopyridin-2-yl)acetate [0249] Into a 20 L 4-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed a solution of 5-bromo-2-methylpyridine (300 g, 1744 mmol, 1 equiv) in THF (10.5 L). The solution was cooled to 0°C and 1M in THF solution of LiHMDS (4 L) was added dropwise with stirring at 0°C. The solution was stirred at low temperature for 30 mins, then diethyl carbonate (311 g, 2633 mmol, 1.5 equiv) was added. The resulting solution was stirred for 5 h at room temperature. The reaction solution was extracted with 5 L of ethyl acetate and the organics dried over anhydrous sodium sulfate. Concentration gave ethyl 2-(5-bromopyridin-2-yl)acetate (400 g, 94% yield) as a black oil. Synthesis of Int.16-b: ethyl (2Z)-2-(5-bromopyridin-2-yl)-2-(N-hydroxyimino)acetate [0250] Into a 5 L 4-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed ethyl 2-(5-bromopyridin-2-yl)acetate (400 g, 1639 mmol, 1 equiv) and AcOH (800 mL). After cooling to 0°C a solution of NaNO ₂ (114 g, 1652 mmol, 1.01 equiv) in H ₂ O (280 mL) was added dropwise with stirring. The resulting solution was stirred for 1 h at room temperature. The reaction was quenched by the addition of 1 L of water, and the resulting solution was extracted with 1 L of ethyl acetate. The organics were dried over anhydrous sodium sulfate and concentrated. This gave ethyl (2Z)-2-(5- bromopyridin-2-yl)-2-(N-hydroxyimino)acetate (450 g) as a crude black oil. Synthesis of Int.16-c: ethyl 2-amino-2-(5-bromopyridin-2-yl)acetate [0251] Into a 10 L 4-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed ethyl (2Z)-2-(5-bromopyridin-2-yl)-2-(N- hydroxyimino)acetate (450 g, 1648 mmol, 1 equiv) and AcOH (4.5 L). The mixture was cooled to 0°C and Zn (318 g, 4862 mmol, 2.95 equiv) was added. The resulting mixture was stirred for 1 h at room temperature. The solids were removed by filtration and the filtrate concentrated to give ethyl 2-amino-2-(5-bromopyridin-2-yl)acetate (379 g, 89% yield) as a black oil. Synthesis of Int.16-d: ethyl 6-bromoimidazo[1,5-a]pyridine-1-carboxylate [0252] Into a 2 L 4-necked round-bottom flask, was placed ethyl 2-amino-2-(5- bromopyridin-2-yl)acetate (379 g, 1463 mmol, 1 equiv) and triethyl orthoformate (645 mL). The resulting solution was stirred for 10 min at 130°C, then concentrated. The residue was applied onto a silica gel column, eluting with ethyl acetate/petroleum ether (1:3). The collected fractions were combined and concentrated to give ethyl 6-bromoimidazo[1,5- a]pyridine-1-carboxylate (125 g, 32% yield) as a black oil. Synthesis of Int.16-e: ethyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5- a]pyridine-1-carboxylate [0253] Into a 5 L 4-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed ethyl 6-bromoimidazo[1,5-a]pyridine-1-carboxylate (125 g, 465 mmol, 1 equiv), dioxane (3125 mL), bis(pinacolato)diboron (178 g, 700 mmol, 1.5 equiv), Pd(dppf)Cl ₂ (38 g, 52 mmol, 0.11 equiv) and KOAc (138 g, 1406 mmol, 3.03 equiv). The resulting solution was stirred for 1 h at 85°C, then concentrated. The residue was suspended in 1 L of EA and the solids removed by filtration. The filtrate was concentrated to give ethyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5-a ]pyridine-1- carboxylate (150 g) as a crude black solid. Synthesis of Intermediate 16: ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine-1- carboxylate [0254] Into a 10 L 4-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed ethyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)imidazo[1,5-a]pyridine-1-carboxylate (100 g, 316 mmol, 1 equiv), 3-bromo-2,4- difluoroaniline (65.5 g, 315 mmol, 1 equiv), dioxane (5 L), Pd(dppf)Cl ₂ .CH ₂ Cl ₂ (25.8 g, 35 mmol, 0.11 equiv), K ₂ CO ₃ (131 g, 947 mmol, 2.99 equiv) and H ₂ O (1 L). The resulting solution was stirred for 2 h at 85°C, then concentrated. The resulting mixture was extracted with 1 L of ethyl acetate and the organics concentrated. The residue was applied onto a silica gel column, eluting with ethyl acetate/petroleum ether (1:4). The collected fractions were combined and concentrated to give ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5- a]pyridine-1-carboxylate (53 g, 53% yield) as a brown solid. LCMS (ES, m/z): 318[M+H]+ 1H NMR (300 MHz, Methanol-d4, ppm): δ 8.58 (s, 1H), 8.46 (s, 1H), 8.16 (d, J = 9.4 Hz, 1H), 7.33 (d, J = 9.5 Hz, 1H), 6.96 – 6.83 (m, 2H), 4.45 (q, J = 7.1 Hz, 2H), 3.21 (s, 1H), 1.45 (t, J = 7.1 Hz, 3H), 1.20 (s, 1H). Example 16: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxamide (Compound 1) Synthesis of 1-a: ethyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5- a]pyridine-1-carboxylate [0255] Ethyl 6-bromoimidazo[1,5-a]pyridine-1-carboxylate (200 mg, 0.75 mmol, 1 equiv), bis(pinacolato)diboron (284 mg, 1.1 mmol, 1.5 equiv), Pd(dppf)Cl ₂ (55 mg, 0.075 mmol, 0.1 equiv) and AcOK (219 mg, 2.24 mmol, 3 equiv) were suspended in dioxane (5 mL). The resulting solution was stirred for 1 h at 85 °C in an oil bath, then cooled and concentrated. The residue was applied to a silica gel column and eluted with ethyl acetate/petroleum ether (1:10). Ethyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5-a ]pyridine-1- carboxylate (188 mg) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 317 Synthesis of 1-b: ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyridine-1-carboxylate [0256] Ethyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5-a ]pyridine-1- carboxylate (188 mg, 0.6 mmol, 1 equiv), N-(3-bromo-2,4-difluorophenyl)-5-chloro-2- methoxypyridine-3-sulfonamide (246 mg, 0.6 mmol, 1 equiv), Pd(dppf)Cl ₂ (44 mg, 0.06 mmol, 0.1 equiv) and K ₂ CO ₃ (246 mg, 1.8 mmol, 3 equiv) were suspended in dioxane (10 mL) and H ₂ O (2 mL). The resulting solution was stirred for 2 h at 85 °C in an oil bath. The reaction mixture was cooled to room temperature and concentrated. The residue was applied onto a silica gel column and eluted with ethyl acetate/petroleum ether (1:1). Ethyl 6-[3-(5- chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]i midazo[1,5-a]pyridine-1- carboxylate (155 mg) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 523 Synthesis of 1-c: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyridine-1-carboxylic acid [0257] Ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyridine-1-carboxylate (155 mg, 0.3 mmol, 1 equiv) in MeOH (10 mL) was treated with a solution of LiOH (22 mg, 0.9 mmol, 3 equiv) in H ₂ O (2 mL) dropwise with stirring at room temperature. The resulting solution was stirred for 1 h at room temperature, then concentrated. The residue was diluted with 10 mL of H ₂ O, and the pH adjusted to 5~6 with HCl (2 mol/L). The resulting solution was extracted with 2 x 10 mL of ethyl acetate. The organic solution was washed with 20 ml of brine and dried over anhydrous sodium sulfate. The filtrate was concentrated under vacuum to give 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]imidazo[1, 5-a]pyridine-1-carboxylic acid (103 mg) as a white solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 495 Synthesis of Compound 1: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxamide [0258] 6-[3-(5-Chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]imidazo[1,5- a]pyridine-1-carboxylic acid (103 mg, 0.21 mmol, 1 equiv), CH ₃ NH ₂ .H ₂ O (14 mg, 0.21 mmol, 1 equiv), HATU (116 mg, 0.31 mmol, 1.5 equiv) and DIEA (40 mg, 0.31 mmol, 1.5 equiv) were dissolved in DMF (5 mL). The resulting solution was stirred for 2 h at room temperature. Concentration gave the crude product (150 mg) which was purified by Flash- Prep-HPLC using the following conditions: (IntelFlash-1): welch Ultimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: Water (0.05% NH ₃ .H ₂ O), Mobile Phase B: ACN, Gradient: 10-35% B; Detector, 220 nm.6-[3-(5-Chloro-2-methoxypyridine-3-sulfonamido)- 2,6-difluorophenyl]-N-methylimidazo[1,5-a]pyridine-1- carboxamide (23 mg) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 508 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.46 (s, 1H), 8.60 (s, 1H), 8.54-8.46 (m, 2H), 8.19-8.05 (m, 3H), 7.44-7.30 (m, 1H), 7.24 (t, J = 9.2 Hz, 1H), 7.02 (d, J = 9.5 Hz, 1H), 3.92 (s, 3H), 2.81 (d, J = 4.7 Hz, 3H). Example 17: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 2) Synthesis of 2-a: 2-(5-bromopyridin-2-yl)-2-[(diphenylmethylidene)amino]aceton itrile [0259] A solution of 5-bromo-2-fluoropyridine (50 g, 284 mmol, 1 equiv), Cs ₂ CO ₃ (278 g, 852 mmol, 3 equiv) and 2-[(diphenylmethylidene)amino]acetonitrile (62.6 g, 284 mmol, 1 equiv) in DMF (1000 mL) was stirred overnight at 100 °C. The mixture was allowed to cool to room temperature and diluted with water (3000 mL), before being extracted with EA (3 x 1000 mL). The combined organic layers were washed with brine (2 x 500 mL) and dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (3/1) to afford 2-(5-bromopyridin-2-yl)-2-[(diphenylmethylidene)amino]aceton itrile (75 g, 70% yield) as a pink oil. LCMS (ES, m/z): [M+H] ⁺ : 376 Synthesis of 2-b: 2-amino-2-(5-bromopyridin-2-yl)acetonitrile [0260] To a stirred solution of 2-(5-bromopyridin-2-yl)-2- [(diphenylmethylidene)amino]acetonitrile (75 g, 199 mmol, 1 equiv) in THF (400 mL) was added 2 M hydrochloric acid (300 mL) dropwise at 0 °C. The resulting mixture was stirred for 1 h at room temperature, then concentrated under reduced pressure to remove THF. The mixture was basified to pH 8 with saturated aqueous NaHCO ₃ . The resulting mixture was extracted with EA (3 x 500 mL). The combined organic layers were washed with brine (300 mL) and dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure to give 2-amino-2-(5-bromopyridin-2-yl)acetonitrile (23.9 g, crude) as a yellow oil which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 212 Synthesis of 2-c: 6-bromoimidazo[1,5-a]pyridine-1-carbonitrile [0261] A solution of 2-amino-2-(5-bromopyridin-2-yl)acetonitrile (23.9 g, 113 mmol, 1 equiv) in triethyl orthoformate (100 mL) was stirred for 30 min at 100 °C. The mixture was cooled to 0 °C and the solid formed collected by filtration and dried under vacuum to give 6- bromoimidazo[1,5-a]pyridine-1-carbonitrile (14 g, 56% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 222 Synthesis of 2-d: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1H-imidazole [0262] To a stirred solution of 6-bromoimidazo[1,5-a]pyridine-1-carbonitrile (14 g, 63 mmol, 1 equiv) in CH ₃ OH (100 mL) was added NaOMe (13.6 g, 252 mmol, 4 equiv) in portions at 0 °C. The resulting mixture was stirred for 3 h at 50 °C then cooled to room temperature. To this was added 2,2-dimethoxyethan-1-amine (5 g, 47 mmol, 1.2 equiv) and AcOH (11.8 g, 197 mmol, 5 equiv), and the mixture was stirred for 1 h at 50 °C. After cooling to room temperature, MeOH (168 mL) was added, followed by 6 M hydrochloric acid (84 mL) dropwise at 0 °C. The resulting mixture was stirred for 5 h at 100 °C. The mixture was allowed to cool and was concentrated under vacuum. The resulting mixture was then diluted with H ₂ O (100 mL) and basified to pH 8 with 2 M NaOH. The resulting solids were filtered and dried under vacuum to give 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1H-imidazole (15.1 g) as a black solid which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 263 Synthesis of 2-e: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole [0263] To a stirred solution of 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1H-imidazole (15 g, 57.3 mmol, 1 equiv) in tetrahydrofuran (150 mL) was added NaH (4.8 g, 200 mmol, 3.5 equiv, 60%) in portions at 0 °C. The resulting mixture was stirred for 0.5 h at 0 °C. SEM-Cl (15.3 mL, 91 mmol, 1.5 equiv) was added dropwise over 10 min at 0 °C and the resulting mixture was stirred for 1 h at room temperature. The reaction was quenched by the addition of H ₂ O (500 mL) and was extracted with EA (3 x 200 mL). The combined organics were washed with brine (2 x 100 mL), then dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/1) to afford 2-[6-bromoimidazo[1,5- a]pyridin-1-yl]-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol e (8 g, 36% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 393 Synthesis of 2-f: 2-[6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1, 5-a]pyridin-1- yl]-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole [0264] To a stirred solution of 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (8 g, 20 mmol, 1 equiv), KOAc (4 g, 41 mmol, 2 equiv) and bis(pinacolato)diboron (5.7 g, 22 mmol, 1.1 equiv) in dioxane (100 mL) was added Pd(dppf)Cl ₂ (1.5 g, 2.03 mmol, 0.1 equiv) in portions at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 2 h at 90 °C under nitrogen atmosphere. The mixture was allowed to cool down to room temperature and then diluted with water (500 mL). The resulting mixture was extracted with EA (3 x 100 mL). The combined organic layers were washed with brine (100 mL), then dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure to give 2-[6- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5-a]p yridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl] imidazole (8.1 g, 90% yield) as a yellow oil which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 441 Synthesis of 2-g: 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0265] To a stirred solution of 2-[6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)imidazo[1,5-a]pyridin-1-yl]-1-[[2-(trimethylsilyl)ethoxy] methyl]imidazole (8.1 g, 18.4 mmol, 1 equiv) and N-(3-bromo-2,4-difluorophenyl)-5-chloro-2-methoxypyridine-3- sulfonamide (9.13 g, 22 mmol, 1.2 equiv) in dioxane (80 mL) and H ₂ O (8 mL) were added K ₂ CO ₃ (7.6 g, 55 mmol, 3 equiv) and Pd(dppf)Cl ₂ (1.35 g, 1.8 mmol, 0.1 equiv) in portions. The resulting mixture was stirred for 3 h at 90 °C under nitrogen atmosphere. The mixture was allowed to cool to room temperature and then diluted with water (200 mL). The resulting mixture was extracted with EA (3 x 100 mL). The combined organic layers were washed with brine (100 mL), then dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/1) to afford 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (5.88 g, 49% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 647 Synthesis of Compound 2: 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0266] A solution of 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a] pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (5.9 g, 9.1 mmol, 1 equiv) in TFA (50 mL) was stirred for 1 h at 70 °C. The resulting mixture was concentrated under reduced pressure and then diluted with water (50 mL). The mixture was basified to pH 8 with saturated aqueous NaHCO ₃ . The resulting mixture was extracted with EA (3 x 100 mL). The combined organic layers were washed with brine (100 mL), then dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.1% NH ₃ ·H ₂ O in Water, Mobile Phase B: MeCN (25-65% over 15 min) Detector, 220 nm; to afford 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3- sulfonamide (2.05 g, 44% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 517 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.52 (d, J = 4.5 Hz, 3H), 8.24 (d, J = 9.4 Hz, 1H), 8.09 (d, J = 2.7 Hz, 1H), 7.38 (td, J = 8.9, 6.0 Hz, 1H), 7.25 (t, J = 9.5 Hz, 1H), 7.08 (s, 2H), 6.84 (d, J = 8.0 Hz, 1H), 3.93 (s, 3H). Example 18: Synthesis of 6-[3-(5-chloro-2-methoxypyridine- 3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 3 Synthesis of 3-a: ethyl 2-(5-bromopyrazin-2-yl)-2-[(diphenylmethylidene) amino] acetate [0267] 2,5-Dibromopyrazine (10 g, 42 mmol, 1 equiv), ethyl 2- [(diphenylmethylidene)amino]acetate (11.8 g, 44 mmol, 1.05 equiv), TBAB (13.6 g, 42 mmol, 1 equiv) and K ₂ CO ₃ (17.4 g, 126 mmol, 3 equiv) in NMP (200 mL) were stirred overnight at 100 °C in an oil bath. The reaction mixture was cooled and filtered. The filtrate was diluted with 200 mL of water. The resulting solution was extracted with 2 x 200 mL of ethyl acetate and the organic layers combined. The resulting mixture was washed with 2 x 200 ml of water. The mixture was dried over anhydrous sodium sulfate and concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/PE (1/10). The collected fractions were combined and concentrated to give ethyl 2-(5-bromopyrazin-2-yl) -2- [(diphenylmethylidene)amino]acetate (8 g, 45% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 424 Synthesis of 3-b: ethyl 2-amino-2-(5-bromopyrazin-2-yl) acetate [0268] Into a 250 mL round-bottom flask, was placed ethyl 2-(5-bromopyrazin-2-yl)-2- [(diphenylmethylidene)amino] acetate (8 g, 18.8 mmol, 1 equiv), THF (10 mL) and HCl (aqueous, 1 M) (20 mL). The resulting solution was stirred for 30 min at 25 °C. The solution formed was diluted with 50 mL of water, and extracted with 2 x 50 mL of dichloromethane. The aqueous layers were adjusted to pH 8 with NH ₃ .H ₂ O and further extracted with 3 x 50 mL of dichloromethane. The combined organic layers were dried over anhydrous sodium sulfate and concentrated. Ethyl 2-amino-2-(5-bromopyrazin-2-yl)acetate (4.7 g, 96% yield) was isolated as a yellow solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 260 Synthesis of 3-c: ethyl 6-bromoimidazo [1,5-a]pyrazine-1-carboxylate [0269] Into a 50 mL round-bottom flask, was placed ethyl 2-amino-2-(5-bromopyrazin-2-yl) acetate (4.2 g, 0.02 mol, 1 equiv) and triethyl orthoformate (20 mL). The resulting solution was stirred for 2 h at 80 °C in an oil bath. The reaction mixture was cooled, and the solids collected by filtration. Air drying gave ethyl 6-bromoimidazo [1,5-a]pyrazine-1-carboxylate (2.2 g, 50% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 270 Synthesis of 3-d: 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) aniline [0270] 3-Bromo-2,4-difluoroaniline (10 g, 48 mmol, 1 equiv), Pd(dppf)Cl ₂ (3.5 g, 4.8 mmol, 0.1 equiv), bis(pinacolato)diboron (18.3 g, 72 mmol, 1.5 equiv) and KOAc (14.2 g, 144.2 mmol, 3 equiv) were dissolved in dioxane (240 mL). The resulting solution was stirred overnight at 100 °C in an oil bath. The reaction mixture was cooled and the solids removed by filtration. The filtrate was concentrated and diluted with DCM (100 mL), then washed with 2 x 100 mL of water and 100 mL of brine. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1/10).2,4-Difluoro-3-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (8 g, 65% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 256 Synthesis of 3-e: ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1-carbo xylate [0271] Ethyl 6-bromoimidazo[1,5-a]pyrazine-1-carboxylate (500 mg, 1.9 mmol, 1 equiv), 2,4-difluoro-3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (708 mg, 2.8 mmol, 1.5 equiv), Pd(dppf)Cl ₂ (135 mg, 0.2 mmol, 0.1 equiv), K ₂ CO ₃ (767 mg, 5.6 mmol, 3 equiv) in dioxane (10 mL) and H ₂ O (2 mL) were stirred for 1 h at 60 °C in an oil bath. The reaction mixture was cooled, diluted with water (20 ml) and extracted with 3 x 20 mL of dichloromethane. The organic layers were dried over anhydrous sodium sulfate and concentrated. The residue was applied to a silica gel column, and eluted with ethyl acetate/PE (1/2). Ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1-carbo xylate (200 mg 34% yield) was isolated as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 319 Synthesis of 3-f: ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylate [0272] Ethyl 6-(3-amino-2, 6-difluorophenyl)imidazo[1,5-a]pyrazine-1- carboxylate (150 mg, 0.5 mmol, 1 equiv) in DCM (5 mL) was treated with pyridine (186 mg, 2.3 mmol, 5 equiv), then 5-chloro-2-methoxypyridine-3-sulfonyl chloride (137 mg, 0.6 mmol, 1.2 equiv). The resulting solution was stirred overnight. The resulting mixture was concentrated and purified by Flash-Prep-HPLC with the following conditions: Column, WelFlashTM C18-I, Spherical C1820-40 μm; mobile phase: 0.1% Formic Acid/ 5-70% MeCN over 15 min; Detector, 254 & 220 nm. Ethyl 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylate (320 mg 97% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 524 Synthesis of 3-g: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a] pyrazine-1-carboxylic acid [0273] Ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylate (200 mg, 0.4 mmol, 1 equiv), MeOH (2 mL), THF (2 mL) , H ₂ O (2 mL) and LiOH (27 mg, 1.1 mmol, 3 equiv) were stirred for 1 h at 60 °C in an oil bath. After concentration, the crude product was purified by Flash-Prep- HPLC with the following conditions: Column, WelFlashTM C18-I, Spherical C1820-40 μm; mobile phase: 5-60% MeCN/0.1% ammonia over 15 min; Detector, 254 nm.6-[3-(5-Chloro- 2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a] pyrazine-1-carboxylic acid (170 mg, 90% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 496 Synthesis of Compound 3: 6-[3-(5-chloro-2-methoxypyridine- 3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide [0274] 6-[3-(5-Chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5- a]pyrazine-1-carboxylic acid (170 mg, 0.3 mmol, 1 equiv) in DMF (4 mL) was treated with DIEA (133 mg, 1 mmol, 3 equiv), methylamine hydrochloride (16 mg, 0.5 mmol, 1.5 equiv) and HATU (195 mg, 0.5 mmol, 1.5 equiv). The resulting solution was stirred for 1 hr, then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlashTM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5- 60% MeCN/0.1% formic acid over 20 min.6-[3-(5-Chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-methylimidazo[1,5-a]pyraz ine-1-carboxamide (43 mg, 25% yield) was isolated as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 509 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.46 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.66 (d, J = 5.0 Hz, 2H), 8.51 (d, J = 2.6 Hz, 1H), 8.43 (d, J = 4.9 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.25 (td, J = 9.3, 1.4 Hz, 1H), 3.92 (s, 3H), 2.84 (d, J = 4.7 Hz, 3H).

Example 19: Synthesis of 2-[3-(5-Chloro-2-methoxypyridine- 3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo [1,5-b]pyridazine-5-carboxamide (Compound 4) Synthesis of 4-a: ethyl 2-(6-chloropyridazin-3-yl)-2-[(diphenylmethylidene)amino] acetate [0275] Into a 500 mL round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 3,6-dichloropyridazine (5 g, 33.5 mmol, 1 equiv), dioxane (160 mL), TBAB (10.8 g, 34 mmol, 1 equiv), Cs ₂ CO ₃ (32.8 g, 100 mmol, 3 equiv) and ethyl 2- [(diphenylmethylidene)amino]acetate (9 g, 34 mmol, 1 equiv). The resulting solution was stirred overnight at 80 °C in an oil bath, then cooled. The resulting mixture was concentrated and the residue applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:5). The appropriate fractions were combined and concentrated to give ethyl 2-(6- chloropyridazin-3-yl)-2-[(diphenylmethylidene)amino] acetate (6 g, 47% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 380 Synthesis of 4-b: ethyl 2-amino-2-(6-chloropyridazin-3-yl)acetate [0276] Into a 250 mL round-bottom flask, was placed ethyl 2-(6-chloropyridazin-3-yl)-2- [(diphenylmethylidene)amino]acetate (6.80 g, 17.9 mmol, 1 equiv), THF (20 mL) and HCl (6 M in water) (20 mL). The resulting solution was stirred for 30 min at 25 °C. The resulting solution was diluted with 50 mL of water, and extracted with 2 x 50 mL of dichloromethane. The aqueous layer was adjusted to pH 8 with NH ₃ .H ₂ O and extracted with further 2 x 50 mL of dichloromethane. The combined organic layers were dried over anhydrous sodium sulfate and concentrated to give ethyl 2-amino-2-(6-chloropyridazin-3-yl)acetate (3.2 g) as a yellow solid, which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 216 Synthesis of 4-c: ethyl 2-chloroimidazo[1,5-b]pyridazine-5-carboxylate [0277] Into a 250 mL round-bottom flask, was placed ethyl 2-amino-2-(6-chloropyridazin-3- yl)acetate (3.1 g, 14.4 mmol, 1 equiv) and triethoxymethane (50 mL). The resulting solution was stirred for 1 h at 80 °C in an oil bath. After concentration, the residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1/1). The appropriate fractions were combined and concentrated to give ethyl 2-chloroimidazo[1,5-b]pyridazine-5- carboxylate (2.4 g, 74% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 226 Synthesis of 4-d: ethyl 2-(3-amino-2,6-difluorophenyl)imidazo[1,5-b]pyridazine-5- carboxylate [0278] Into a 40 mL vial, was placed ethyl 2-chloroimidazo[1,5-b]pyridazine-5-carboxylate (500 mg, 2.2 mmol, 1 equiv), H ₂ O (2 mL), dioxane (10 mL), Sphos (182 mg, 0.4 mmol, 0.2 equiv), SPhosPdGen.3 (173 mg, 0.2 mmol, 0.1 equiv), 2,4-difluoro-3-(4,4,5,5- tetramethyl- 1,3,2-dioxaborolan-2-yl)aniline (1.1 g, 4.4 mmol, 2 equiv) and K ₂ CO ₃ (766 mg, 5.5 mmol, 2.5 equiv). The resulting solution was stirred for 1 h at 80 °C in an oil bath. The reaction mixture was cooled and concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1/1). The appropriate fractions were combined and concentrated to give ethyl 2-(3-amino-2,6-difluorophenyl)imidazo[1,5-b]pyridazine-5- carboxylate (340 mg, 48% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 319 Synthesis of 4-e: 2-(3-amino-2,6-difluorophenyl)- N-methylimidazo[1,5-b]pyridazine-5- carboxamide [0279] Into a 50 mL round-bottom flask, was placed ethyl 2-(3-amino-2,6- difluorophenyl)imidazo[1,5-b]pyridazine-5- carboxylate (330 mg, 1 mmol, 1 equiv) and methylamine (5 mL, 33% in alcohol). The resulting solution was stirred overnight at 60 °C in an oil bath. The reaction mixture was cooled and concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-60% MeCN/0.1% Formic Acid over 20 min; Detector, UV 254 nm.2-(3-Amino-2,6-difluorophenyl)- N-methylimidazo[1,5- b]pyridazine-5-carboxamide (240 mg, 76% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 304 Synthesis of Compound 4: 2-[3-(5-Chloro-2-methoxypyridine- 3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo [1,5-b]pyridazine-5-carboxamide [0280] Into an 8 mL vial, was placed 2-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- b]pyridazine-5-carboxamide (70 mg, 0.2 mmol, 1 equiv), DCM (2 mL), pyridine (91 mg, 1.1 mmol, 5 equiv) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (84 mg, 0.3 mmol, 1.5 equiv). The resulting solution was stirred overnight at 36 °C in an oil bath. The resulting mixture was concentrated. The crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.1% FA in Water, Mobile Phase B: ACN (44% Phase B up to 58% in 8 min); Detector, 220 nm.2-[3-(5-Chloro-2-methoxypyridine- 3-sulfonamido)-2,6-difluorophenyl]- N-methylimidazo[1,5-b]pyridazine-5-carboxamide (69 mg, 59% yield) was isolated as an off- white solid. LCMS (ES, m/z): [M+H] ⁺ : 509 [M+H] ^{+ 1} H NMR (300 MHz, DMSO-d ₆ ) δ 10.53 (s, 1H), 8.87 (s, 1H), 8.58 (d, J = 9.5 Hz, 1H), 8.51 (d, J = 2.6 Hz, 1H), 8.33 (d, J = 4.8 Hz, 1H), 8.10 (d, J = 2.6 Hz, 1H), 7.50 (td, J = 9.0, 5.9 Hz, 1H), 7.30 (td, J = 9.1, 1.6 Hz, 1H), 7.13 (dt, J = 9.4, 1.3 Hz, 1H), 3.91 (s, 3H), 2.82 (d, J = 4.7 Hz, 3H). Example 20: Synthesis of 2-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-b]pyridazine-5-carboxami de (Compound 5) Compound 5 Synthesis of 5-a: 3-bromo-5-chloro-2-methylpyridine [0281] Into a round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed 2,3-dibromo-5-chloropyridine (5 g, 18 mmol, 1 equiv), dioxane (90 mL), K ₂ CO ₃ (7.6 g, 55 mmol, 3 equiv), Pd(PPh ₃ ) ₄ (2.1 g, 1.8 mmol, 0.1 equiv) and a 50% yield solution of trimethyl-1,3,5,2,4,6-trioxatriborinane (2.3 g, 18.3 mmol, 1 equiv) in THF. The resulting solution was stirred at 110 °C in an oil bath for three days, adding a 50% solution of trimethyl-1,3,5,2,4,6-trioxatriborinane (2.3 g, 18.3 mmol, 1 equiv) in THF each day. The reaction mixture was cooled, and the resulting mixture was concentrated at low temperature (the product has a low bp., it can easily be removed with solvent). The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:10).3- Bromo-5-chloro-2-methylpyridine (2 g, 53% yield) was obtained as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 205 Synthesis of 5-b: 3-(benzylsulfanyl)-5-chloro-2-methylpyridine [0282] Into a 50 mL round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 3-bromo-5-chloro-2-methylpyridine (850 mg, 4 mmol, 1 equiv), dioxane (20 mL), DIEA (1.06 g, 8.2 mmol, 2 equiv), Xantphos (476 mg, 0.8 mmol, 0.2 equiv), Pd ₂ (dba) ₃ (377 mg, 0.4 mmol, 0.1 equiv) and benzyl mercaptan (767 mg, 6.1 mmol, 1.5 equiv). The resulting solution was stirred for 2 h at 100 °C in an oil bath. The reaction mixture was cooled, and concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:20).3-(Benzylsulfanyl)-5-chloro-2-methylpyridine (500 mg, 49% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 250 Synthesis of 5-c: 5-chloro-2- methylpyridine-3-sulfonyl chloride [0283] Into a 20 mL vial was placed MeCN (6 mL) and HCl (6 M in water, 1.2 mL). This was followed by the addition of NCS (428 mg, 3.2 mmol, 4 equiv) in portions at 0 °C. The mixture was stirred for 10 mins, then 3-(benzylsulfanyl)-5-chloro-2-methylpyridine (200 mg, 0.8 mmol, 1 equiv) was added in portions at 0 °C. The resulting solution was stirred for 30 min at 0 °C in a water/ice bath. The reaction was quenched by the addition of 20 mL of water. The resulting solution was extracted with 2 x 20 mL of dichloromethane and the organic layers combined. The organics were washed with 2 x 20 mL of water and the mixture dried over anhydrous sodium sulfate before being concentrated.5-Chloro-2- methylpyridine- 3-sulfonyl chloride (300 mg crude) was isolated as a yellow oil, which was used in next step directly without further purification. Synthesis of Compound 5: 2-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-b]pyridazine-5-carboxami de [0284] Into an 8 mL vial, was placed 2-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- b]pyridazine-5-carboxamide (60 mg, 0.2 mmol, 1 equiv), DCM (2 mL), pyridine (313 mg, 4 mmol, 20 equiv) and 5-chloro-2-methylpyridine-3-sulfonyl chloride (268 mg, 1.2 mmol, 6 equiv). The resulting solution was stirred overnight at 36 °C in an oil bath. The reaction mixture was concentrated, and the crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, 30-60% MeCN over 20 mins/0.1% aqueous formic acid; Detector, UV 254 nm.2-[3-(5- Chloro-2-methylpyridine-3-sulfonamido)-2,6-difluorophenyl]-N -methylimidazo[1,5- b]pyridazine-5-carboxamide (68 mg, 69% yield) was obtained as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 493 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.87 (s, 1H), 8.86 (s, 1H), 8.78 (d, J = 2.4 Hz, 1H), 8.58 (d, J = 9.5 Hz, 1H), 8.32 (q, J = 4.6 Hz, 1H), 8.08 (d, J = 2.4 Hz, 1H), 7.50 (td, J = 8.9, 5.8 Hz, 1H), 7.32 (td, J = 9.1, 1.6 Hz, 1H), 7.10 (dt, J = 9.4, 1.3 Hz, 1H), 2.82 (d, J = 4.8 Hz, 3H), 2.77 (s, 3H). Example 21: Synthesis of 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxa mide (Compound 6) Synthesis of 6-a: N-(3-bromo-2,4-difluorophenyl)-5-fluoro-2-methylpyridine-3-s ulfonamide [0285] Into a 25 mL 3-necked round-bottom flask, was placed 3-bromo-2,4-difluoroaniline (596 mg, 2.9 mmol, 1 equiv), DCM (10 mL), pyridine (679 mg, 8.6 mmol, 3 equiv) and 5- fluoro-2-methylpyridine-3-sulfonyl chloride (600 mg, 2.9 mmol, 1 equiv). The resulting solution was stirred for 30 min at room temperature. The mixture was concentrated under reduced pressure, and the residue purified by silica gel column chromatography, eluting with PE:EA (2:1) to afford N-(3-bromo-2,4-difluorophenyl)-5-fluoro-2-methylpyridine-3- sulfonamide (760 mg, 70% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 381 Synthesis of 6-b: ethyl 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido)p henyl] imidazo[1,5-a]pyridine-1-carboxylate [0286] Into a 25 mL 3-necked round-bottom flask, was placed ethyl 6-(4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl)imidazo[1,5-a]pyridine-1-carboxylate (200 mg, 0.6 mmol, 1 equiv), dioxane (10 mL), N-(3-bromo-2,4-difluorophenyl)-5-fluoro-2-methylpyridine-3-s ulfonamide (241 mg, 0.6 mmol, 1 equiv), K ₂ CO ₃ (262 mg, 1.9 mmol, 3 equiv), H ₂ O (0.8 mL) and Pd(dppf)Cl ₂ (46 mg, 0.06 mmol, 0.1 equiv) in one portion at room temperature under N ₂ atmosphere. The resulting solution was stirred for 2 h at 85 °C in an oil bath under N ₂ atmosphere. The mixture was allowed to cool to room temperature and was filtered. The filtrate was concentrated under reduced pressure and the residue purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford ethyl 6-[2,6-difluoro-3-(5-fluoro-2- methylpyridine-3-sulfonamido)phenyl]imidazo[1,5-a]pyridine-1 -carboxylate (200 mg, 64% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 491 Synthesis of 6-c: 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]imidazo[1,5-a]pyridine-1-carboxylic acid [0287] Into a 25 mL round-bottom flask, was placed ethyl 6-[2,6-difluoro-3-(5-fluoro-2- methylpyridine-3-sulfonamido)phenyl]imidazo[1,5-a]pyridine-1 -carboxylate (200 mg, 0.4 mmol, 1 equiv), MeOH (10 mL), H ₂ O (2 mL) and LiOH (30 mg, 1.3 mmol, 3 equiv). The resulting solution was stirred for 1 h at room temperature. The reaction mixture was concentrated under vacuum, and the residue suspended in water (20 mL) and EA (10 mL). The aqueous was extracted with 2 x 10 mL of ethyl acetate, then the pH was adjusted to 2 with HCl (4 M). This was extracted with 3 x 10 mL of ethyl acetate and the organic layers were combined. The resulting mixture was washed with 10 mL of brine. The mixture was dried over anhydrous sodium sulfate and concentrated under reduced pressure to give crude 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido)p henyl]imidazo[1,5-a]pyridine- 1-carboxylic acid (153 mg) as a white solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 463 Synthesis of Compound 6: 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxa mide [0288] Into a 25 mL round-bottom flask, was placed 6-[2,6-difluoro-3-(5-fluoro-2- methylpyridine-3-sulfonamido)phenyl]imidazo[1,5-a]pyridine-1 -carboxylic acid (153 mg, 0.3 mmol, 1 equiv), DMF (5 mL), CH ₃ NH ₂ .HCl (22 mg, 0.3 mmol, 1 equiv), HATU (184 mg, 0.5 mmol, 1.5 equiv) and DIEA (60 mg, 0.5 mmol, 1.5 equiv). The resulting solution was stirred for 2 h at room temperature. The reaction mixture was quenched with H ₂ O (20 mL) and the aqueous layer extracted with 2 x 20 mL of dichloromethane. The organics were combined and washed with water (20 mL x 3) and brine (20 mL), then dried over anhydrous sodium sulfate. After concentration, the residue was purified by prep-HPLC with the following conditions Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.05% NH ₄ HCO ₃ in Water, Mobile Phase B: MeCN (15-40% over 15 min) to afford 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido)p henyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide (22.6 mg, 14% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 476 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.79 (s, 1H), 8.70 (d, J = 2.8 Hz, 1H), 8.58 (s, 1H), 8.48 (s, 1H), 8.18-8.06 (m, 2H), 7.95 (dd, J = 8.3, 2.8 Hz, 1H), 7.40-7.27 (m, 1H), 7.20 (t, J = 9.3 Hz, 1H), 6.98 (d, J = 9.4 Hz, 1H), 2.80 (d, J = 4.5 Hz, 3H), 2.77 (d, J = 1.2 Hz, 3H). Example 22: Synthesis of 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxa mide (Compound 7) Synthesis of 7-a: ethyl 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]imidazo[1,5-a]pyridine-1-carboxylate [0289] Into a 25 mL round-bottom flask, was placed DCM (5 mL), ethyl 6-(3-amino-2,6- difluorophenyl)imidazo[1,5-a]pyridine-1-carboxylate (150 mg, 0.5 mmol, 1 equiv), pyridine (112 mg, 1.5 mmol, 3 equiv) and 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (120 mg, 0.5 mmol, 1 equiv). The resulting solution was stirred for 30 min at room temperature. The mixture was concentrated under reduced pressure to give crude ethyl 6-[2,6-difluoro-3-(5- fluoro-2-methoxypyridine-3-sulfonamido)phenyl]imidazo[1,5-a] pyridine-1-carboxylate (200 mg) as a yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 507 Synthesis of 7-b: 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]imidazo[1,5-a]pyridine-1-carboxylic acid [0290] Into a 50 mL round-bottom flask, was placed MeOH (10 mL), ethyl 6-[2,6-difluoro-3- (5-fluoro-2-methoxypyridine-3-sulfonamido)phenyl]imidazo[1,5 -a]pyridine-1-carboxylate (200 mg, 0.4 mmol, 1 equiv), H ₂ O (2 mL) and LiOH (29 mg, 1.2 mmol, 3 equiv). The resulting solution was stirred for 1 h at room temperature, then concentrated under vacuum. The residue was diluted with water (20 mL) and EA (10 mL). The water layer was extracted with 2 x 10 mL of ethyl acetate. The aqueous layers were adjusted to pH 2 with HCl (4 M) and then extracted with 3 x 10 mL of ethyl acetate. The organic layers were combined, washed with 10 mL of brine and dried over anhydrous sodium sulfate. Concentration under reduced pressure gave crude 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]imidazo[1,5-a]pyridine-1-carboxylic acid (120 mg) as a light yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 479 Synthesis of Compound 7: 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxa mide [0291] Into a 25 mL round-bottom flask, was placed DMF (5 mL), 6-[2,6-difluoro-3-(5- fluoro-2-methoxypyridine-3-sulfonamido)phenyl]imidazo[1,5-a] pyridine-1-carboxylic acid (120 mg, 0.3 mmol, 1 equiv), CH ₃ NH ₂ .HCl (17 mg, 0.3 mmol, 1 equiv), HATU (143 mg, 0.4 mmol, 1.5 equiv) and DIEA (49 mg, 0.4 mmol, 1.5 equiv). The resulting solution was stirred for 2 h at room temperature. The resulting mixture was concentrated and the residue purified by prep-HPLC with the following conditions Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.05% NH ₄ HCO ₃ in Water, Mobile Phase B: MeCN (20% to 50% over 15 min) to afford 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxa mide (50 mg, 39% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 491 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 8.60 (s, 1H), 8.52-8.44 (m, 2H), 8.19-8.08 (m, 2H), 8.04 (dd, J = 7.3, 3.0 Hz, 1H), 7.37 (td, J = 8.9, 5.8 Hz, 1H), 7.31-7.19 (m, 1H), 7.01 (dd, J = 9.5, 1.5 Hz, 1H), 3.91 (s, 3H), 2.84-2.77 (m, 3H). Example 23: Synthesis of 6-[3-(5-cyano-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxamide (Compound 8) Synthesis of 8-a: ethyl 6-[3-(5-cyano-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyridine-1-carboxylate [0292] Into a 25 mL round-bottom flask, was placed DCM (5 mL), ethyl 6-(3-amino-2,6- difluorophenyl)imidazo[1,5-a]pyridine-1-carboxylate (150 mg, 0.5 mmol, 1 equiv), pyridine (112 mg, 1.4 mmol, 3 equiv) and 5-cyano-2-methoxypyridine-3-sulfonyl chloride (110 mg, 0.5 mmol, 1 equiv). The resulting solution was stirred for 30 min at room temperature. The mixture was concentrated under reduced pressure to give crude ethyl 6-[3-(5-cyano-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]imidazo[1, 5-a]pyridine-1-carboxylate (200 mg) as a yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 514 Synthesis of 8-b: 6-[3-(5-cyano-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyridine-1-carboxylic acid [0293] Into a 50 mL round-bottom flask, was placed MeOH (10 mL), ethyl 6-[3-(5-cyano-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]imidazo[1, 5-a]pyridine-1-carboxylate (200 mg, 0.4 mmol, 1 equiv), H ₂ O (2 mL) and LiOH (28 mg, 1.2 mmol, 3 equiv). The resulting solution was stirred for 1 h at room temperature, then concentrated under vacuum. The residue was diluted with water (20 mL). The water layer was extracted with ethyl acetate (3 x 10 mL). The aqueous layers were adjusted to pH 2 with HCl (4 M), and then extracted with ethyl acetate (3 x 10 mL). The organics were combined, washed with brine (10 mL) and dried over anhydrous sodium sulfate. Concentration gave crude 6-[3-(5-cyano-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]imidazo[1, 5-a]pyridine-1-carboxylic acid (120 mg) as a yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 486 Synthesis of Compound 8: 6-[3-(5-cyano-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxamide [0294] Into a 25 mL round-bottom flask, was placed DMF (5 mL), 6-[3-(5-cyano-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]imidazo[1, 5-a]pyridine-1-carboxylic acid (120 mg, 0.3 mmol, 1 equiv), CH ₃ NH ₂ .HCl (16 mg, 0.3 mmol, 1 equiv), HATU (141 mg, 0.4 mmol, 1.5 equiv) and DIEA (48 mg, 0.4 mmol, 1.5 equiv). The resulting solution was stirred for 2 h at room temperature, then diluted with H ₂ O (50 ml). The resulting solution was extracted with 2 x 50 mL of dichloromethane and the organic layers combined and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.05% NH ₄ HCO ₃ in Water, Mobile Phase B: MeCN (20% to 40% over 10 min) to afford 6-[3-(5- cyano-2-methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N -methylimidazo[1,5- a]pyridine-1-carboxamide (13 mg, 10%) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 498 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.83 (s, 1H), 8.58 (s, 1H), 8.47 (s, 1H), 8.41 (s, 1H), 8.17- 8.05 (m, 2H), 7.30 (d, J = 6.8 Hz, 1H), 7.10 (s, 1H), 7.03 (d, J = 9.5 Hz, 1H), 3.96 (s, 3H), 2.80 (d, J = 4.7 Hz, 3H).

Example 24: Synthesis of 6-[3-(5-cyano-2-methylpyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo [1,5-a]pyridine-1-carboxamide (Compound 9) Synthesis of 9-a: methyl 5-bromo-6-iodopyridine-3-carboxylate [0295] To a stirred solution of methyl 5-bromo-6-chloropyridine-3-carboxylate (40 g, 0.16 mol, 1 equiv) in MeCN (1.2 L) was added TMSI (33 g, 0.17 mol, 1.05 equiv) and NaI (72 g, 0.48 mol, 3 equiv). The mixture was stirred at room temperature overnight, then concentrated. H ₂ O (0.8 L) was added, and the solution made basic with 2 M aqueous NaOH. The mixture was extracted with DCM (800 mL x 3) and the organic layer dried over Na ₂ SO ₄ . After concentration, the residue was purified by silica gel column chromatography, eluting with PE:EA (10:1) to afford methyl 5-bromo-6-iodopyridine-3- carboxylate (40 g, 73% yield) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 342 Synthesis of 9-b: methyl 5-bromo-6-methylpyridine-3-carboxylate [0296] To a stirred solution of methyl 5-bromo-6-iodopyridine-3-carboxylate (10 g, 29 mmol, 1 equiv) in dioxane (293 mL) was added K ₂ CO ₃ (12 g, 88 mmol, 3 equiv), trimethyl- 1,3,5,2,4,6-trioxatriborinane (3.7 g, 29 mmol, 1 equiv) and Pd(PPh ₃ ) ₄ (3.4 g, 2.9 mmol, 0.1 equiv). After stirring overnight at 110 °C under a nitrogen atmosphere, LCMS showed 50% desired product and 50% starting material remained, so another batch of trimethyl- 1,3,5,2,4,6-trioxatriborinane (3.7 g, 29 mmol, 1 equiv) was added, and the resulting mixture was stirred at 110 °C overnight. After cooling, the resulting mixture was filtered, and the filter cake was washed with EA (100 mL). The filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA(10:1) to afford methyl 5-bromo-6-methylpyridine-3-carboxylate (5 g, 74% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 230 Synthesis of 9-c: 5-bromo-6-methylpyridine-3-carboxamide [0297] Methyl-5-bromo-6-methylpyridine-3-carboxylate (3.5 g) was added to 7 M NH ₃ in MeOH (70 mL) and stirred at 90 °C in a sealed tube overnight. The reaction solution was concentrated directly to give 5-bromo-6-methylpyridine-3-carboxamide (4 g, crude) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 215 Synthesis of 9-d: 5-bromo-6-methylpyridine-3-carbonitrile [0298] To a stirred solution of 5-bromo-6-methylpyridine-3-carboxamide (3 g, 14 mmol, 1 equiv) in THF (60 mL) was added TEA (3.5 g, 35 mmol, 2.5 equiv) and TFAA (6 g, 28 mmol, 2 equiv). The reaction was stirred at room temperature for 2 hours, then concentrated. The residue was purified by silica gel column chromatography, eluting with PE:EA (20:1) to afford 5-bromo-6-methylpyridine-3-carbonitrile (2 g, 74% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 197 Synthesis of 9-e: 5-(benzylsulfanyl)-6-methylpyridine-3-carbonitrile [0299] To a stirred solution of 5-bromo-6-methylpyridine-3-carbonitrile (2 g, 10 mmol, 1 equiv) in dioxane (26 mL) was added benzyl mercaptan (1.9 g, 15 mmol, 1.5 equiv), DIEA (2.6 g, 20 mmol, 2 equiv), XantPhos (1.2 g, 2 mmol, 0.2 equiv) and Pd ₂ (dba) ₃ .CHCl ₃ (1 g, 1 mmol, 0.1 equiv) under N ₂ atmosphere. The resulting solution was stirred at 120 °C for 2 h, then concentrated directly. The residue was purified by silica gel column chromatography, eluting with PE:EA (10:1) to afford 5-(benzylsulfanyl)-6-methylpyridine-3-carbonitrile (2 g, 82% yield) as a red solid. LCMS (ES, m/z): [M+H] ⁺ : 241 Synthesis of 9-f: 5-cyano-2-methylpyridine-3-sulfonyl chloride [0300] To a stirred solution of 5-(benzylsulfanyl)-6-methylpyridine-3-carbonitrile (0.5 g, 2.1 mmol, 1 equiv) in MeCN (10 mL) was added 6 M HCl (5 mL) dropwise at 0 °C and then NCS (1.1 g, 8.4 mmol, 4 equiv) was added. The reaction was stirred at 0 °C for 10 min. The resulting mixture was diluted with H ₂ O (10 mL) and the aqueous layer extracted with DCM (20 mL x 3). The combined organics were dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (5:1) to afford 5-cyano-2-methylpyridine-3-sulfonyl chloride (0.24 g, 53% yield) as a yellow oil. Synthesis of Compound 9: 6-[3-(5-cyano-2-methylpyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo [1,5-a]pyridine-1-carboxamide [0301] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyridine-1-carboxamide (180 mg, 0.6 mmol, 1 equiv) in DCM (3 mL) was added 5-cyano- 2-methylpyridine-3-sulfonyl chloride (206 mg, 0.95 mmol, 1.6 equiv) and pyridine (141 mg, 1.8 mmol, 3 equiv) at 0 °C. The reaction was stirred at room temperature for 30 min, then concentrated. The residue was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.1% aqueous formic acid, Mobile Phase B: MeCN (10% to 50% over 15 min) to give 6-[3-(5- cyano-2-methylpyridine-3-sulfonamido)-2,6-difluorophenyl]-N- methylimidazo[1,5- a]pyridine-1-carboxamide (121 mg, 42% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 483. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.88 (s, 1H), 9.14 (d, J = 2.0 Hz, 1H), 8.58 (s, 1H), 8.53 (d, J = 2.0 Hz, 1H), 8.49 (s, 1H), 8.20 -8.05 (m, 2H), 7.42-7.34 (m, 1H), 7.26 (td, J = 9.1, 1.5 Hz, 1H), 7.03-6.92 (m, 1H), 2.89 (s, 3H), 2.83-2.79 (m, 3H). Example 25: Synthesis of 6-[2,6-difluoro-3-(6-fluoro-1-hydroxy-2,3-dihydro-1H-indene- 4-sulfonamido)phenyl]-N-methylimidazo[1,5-a]pyridine-1-carbo xamide (Compound 10) Synthesis of 10-a1: 1,3-diethyl 2-[(2-bromo-4-fluorophenyl)methyl]propanedioate [0302] Into a 50 mL round-bottom flask was placed NaH (1.1 g, 46 mmol, 2.5 equiv) and 1,2-dimethoxyethane (5 mL). This was followed by the addition of diethyl malonate (4.3 mL) in 1,2-dimethoxyethane (10 mL) dropwise at 0 °C. The resulting solution was stirred for 1.5 hr at room temperature. To this was added 2-bromo-1-(bromomethyl)-4-fluorobenzene (5.0 g, 18.7 mmol, 1 equiv) in 1,2-dimethoxyethane (10 mL) dropwise at 0 °C. The resulting solution was stirred for 1.5 hr at 85 °C. The reaction was quenched with 100 mL of water/ice, and extracted with 3x30 mL of ethyl acetate. The combined organics were dried over anhydrous sodium sulfate and concentrated. The crude product was purified by Flash- Prep-HPLC with the following conditions: Column, silica gel; mobile phase, 0-20% ethyl acetate in petroleum ether; Detector, 254/280 nm.1,3-Diethyl 2-[(2-bromo-4- fluorophenyl)methyl]propanedioate (6 g, 93% yield) was isolated as a solid. Synthesis of 10-a2: 3-(2-bromo-4-fluorophenyl)propanoic acid [0303] Into a 100 mL round-bottom flask was placed 1,3-diethyl 2-[(2-bromo-4- fluorophenyl)methyl]propanedioate (6.0 g, 17 mmol, 1 equiv) and H ₂ O (40 mL). This was followed by the addition of KOH (2.0 g, 36 mmol, 2.1 equiv). The resulting solution was stirred for 4.5 h at 100 °C then was cooled to 0 °C. H ₂ SO ₄ (4.0 mL, 75 mmol, 4.3 equiv) was added and the resulting solution was stirred overnight at 120 °C. The solids were removed by filtration and dried to give 3-(2-bromo-4-fluorophenyl)propanoic acid (1.6 g, 37% yield) as a solid. Synthesis of 10-a3: 4-bromo-6-fluoro-2,3-dihydroinden-1-one [0304] Into a 100 mL round-bottom flask was placed 3-(2-bromo-4-fluorophenyl)propanoic acid (1.6 g, 6.5 mmol, 1 equiv) in DCM (16 ml). Oxalyl chloride (0.6 ml, 7.2 mmol) was added dropwise at 0 °C and the resulting solution was stirred for 18 hr at RT. The mixture was concentrated. The acid chloride was dissolved in DCM (30 ml), and AlCl ₃ (1 g, 1.20 equiv) was added at 0 °C, and the resulting solution was stirred for 2 hr at 40 °C. The reaction was quenched by the addition of 100 mL of water and extracted with 3x20 mL of dichloromethane. The combined organics were washed with 50 ml of 1 M NaOH, dried over anhydrous sodium sulfate and concentrated. 4-Bromo-6-fluoro-2,3-dihydroinden-1-one (314 mg, 21% yield) was isolated as a solid. Synthesis of 10-a4: 4-(benzylsulfanyl)-6-fluoro-2,3-dihydroinden-1-one [0305] Into a 50 mL round-bottom flask purged and maintained with an inert atmosphere of nitrogen was placed 4-bromo-6-fluoro-2,3-dihydroinden-1-one (1.8 g, 7.6 mmol, 1 equiv), benzyl mercaptan (1.1 mL, 1.6 mmol, 1.2 equiv), toluene (20 mL), DIEA (2.5 mL, 15 mmol, 2 equiv) and Xantphos (444 mg, 0.77 mmol, 0.1 equiv). The resulting solution was stirred for 2 hr at 90 °C and then concentrated. The crude product was purified by silica gel chromatography, eluting with 0-10% ethyl acetate/petroleum ether to give 4-(benzylsulfanyl)- 6-fluoro-2,3-dihydroinden-1-one (1.1 g, 53% yield) as a solid. Synthesis of 10-a: 4-(benzylsulfanyl)-6-fluoro-2,3-dihydro-1H-inden-1-ol [0306] To a stirred solution of 4-(benzylsulfanyl)-6-fluoro-2,3-dihydroinden-1-one (600 mg, 2.2 mmol, 1 equiv) in MeOH (12 mL) was added NaBH ₄ (416 mg, 11 mmol, 5 equiv) at 0 °C and the reaction was stirred at room temperature for 30 min. The solution was concentrated and diluted with DCM (5 mL), then washed with H ₂ O (5 mL x 3). The organic layer was dried (MgSO ₄ ) and concentrated, and the residue was purified by silica gel column chromatography, eluting with PE:EA (3:1) to afford 4-(benzylsulfanyl)-6-fluoro-2,3-dihydro- 1H-inden-1-ol (0.6 g, 99%) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 275 Synthesis of 10-b: 4-(benzylsulfanyl)-6-fluoro-2,3-dihydro-1H-inden-1-yl acetate [0307] Into a 50 mL 3-necked round-bottom flask, was placed 4-(benzylsulfanyl)-6-fluoro- 2,3-dihydro-1H-inden-1-ol (680 mg, 2.5 mmol, 1 equiv), DCM (20 mL), TEA (301 mg, 3.0 mmol, 1.2 equiv) and DMAP (30 mg, 0.25 mmol, 0.1 equiv). This was followed by the addition of acetic anhydride (380 mg, 3.7 mmol, 1.5 equiv) dropwise with stirring at 0 °C. The resulting solution was stirred for 2 h at 25 °C. The reaction was then quenched by the addition of 50 mL of water. The resulting solution was extracted with 3 x 30 mL of dichloromethane and the combined organics were washed with 50 ml of brine. The mixture was dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE:EA (3:1) to afford 4- (benzylsulfanyl)-6-fluoro-2,3-dihydro-1H-inden-1-yl acetate (580 mg, 74% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 317 Synthesis of 10-c: 4-(chlorosulfonyl)-6-fluoro-2,3-dihydro-1H-inden-1-yl acetate [0308] Into a 50 mL 3-necked round-bottom flask, was placed 4-(benzylsulfanyl)-6-fluoro- 2,3-dihydro-1H-inden-1-yl acetate (520 mg, 1.6 mmol, 1 equiv), CH ₃ CN (10 mL) and HCl (6 mol/L, 5 mL). This was followed by the addition of NCS (878 mg, 6.6 mmol, 4 equiv) in portions at 0 °C. The resulting solution was stirred for 30 min at 0 °C. The reaction was quenched by the addition of 50 mL of water and extracted with 3 x 30 mL of ethyl acetate. The combined organics were washed with 50 ml of water and 50 mL of brine, then dried over anhydrous sodium sulfate. Concentration gave crude 4-(chlorosulfonyl)-6-fluoro-2,3-dihydro- 1H-inden-1-yl acetate (450 mg) which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 293 Synthesis of 10-d: 6-[2,6-difluoro-3-(6-fluoro-1-hydroxy-2,3-dihydro-1H-indene- 4- sulfonamido)phenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxa mide [0309] Into a 40 mL vial, was placed 4-(chlorosulfonyl)-6-fluoro-2,3-dihydro-1H-inden-1-yl acetate (116 mg, 0.4 mmol, 1.2 equiv), DCM (10 mL), pyridine (79 mg, 0.1 mmol, 3 equiv) and 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5-a]pyridin e-1-carboxamide (100 mg, 0.3 mmol, 1 equiv). The resulting solution was stirred for 2 days at 25 °C. The mixture was concentrated under vacuum and purified by Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; Mobile Phase A: 0.1% aqueous formic acid, Mobile Phase B: MeCN (10-80% over 15 min) to give 6-[2,6-difluoro- 3-(6-fluoro-1-hydroxy-2,3-dihydro-1H-indene-4-sulfonamido)ph enyl]-N-methylimidazo[1,5- a]pyridine-1-carboxamide (103 mg, 62% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 559 Synthesis of Compound 10: 6-[2,6-difluoro-3-(6-fluoro-1-hydroxy-2,3-dihydro-1H-indene- 4- sulfonamido)phenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxa mide [0310] Into a 40 mL vial, was placed 6-[2,6-difluoro-3-(6-fluoro-1-hydroxy-2,3-dihydro-1H- indene-4-sulfonamido)phenyl]-N-methylimidazo[1,5-a]pyridine- 1-carboxamide (100 mg, 0.18 mmol, 1 equiv), THF (10 mL), H ₂ O (1 mL) and NaOH (14 mg, 0.36 mmol, 2 equiv). The resulting solution was stirred for 24 h at 60 °C. The reaction mixture was cooled and concentrated under vacuum and the pH of the solution was adjusted to 7 with HCl. After further concentration, the crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.1% aqueous formic acid, Mobile Phase B: MeCN (10-15% over 15 min) to give 6-[2,6-difluoro-3-(6-fluoro-1-hydroxy-2,3-dihydro-1H-indene- 4-sulfonamido)phenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide (35 mg, 38% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 517 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.40 (s, 1H), 8.54 (s, 1H), 8.47 (d, J = 0.6 Hz, 1H), 8.18- 8.04 (m, 2H), 7.48-7.18 (m, 4H), 6.96 (dd, J = 9.4, 1.5 Hz, 1H), 5.60 (d, J = 5.6 Hz, 1H), 5.12-5.00 (m, 1H), 3.13-2.99 (m, 1H), 2.84-2.72 (m, 3H), 2.44-2.27 (m, 1H), 1.84-1.66 (m, 1H).

Example 26: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,5-dimethyl imidazo[1,5-a]pyridine-1-carboxamide (Compound 11) Compound 11 Synthesis of 11-a: ethyl 2-(5-bromo-6-methylpyridin-2-yl)-2- [(diphenylmethylidene)amino]acetate [0311] To a solution of 3-bromo-6-fluoro-2-methylpyridine (5 g, 26 mmol, 1 equiv) in MeCN (100 mL) were added ethyl 2-[(diphenylmethylidene)amino]acetate (8.44 g, 31.2 mmol, 1.2 equiv), Cs ₂ CO ₃ (12.86 g, 40 mmol, 1.5 equiv) and TBAB (4.24 g, 13 mmol, 0.5 equiv) at room temperature. The resulting mixture was stirred at 80 °C for 12 h. After cooling to room temperature, water (500 mL) was added and the mixture extracted with ethyl acetate (3 x 200 mL). The combined organics were washed with brine (2 x 50 mL), dried over anhydrous Na ₂ SO ₄ and filtered. The filtrate was concentrated under reduced pressure to give the crude product, which was purified by silica gel chromatography (eluent: PE:EA 8:1) to afford ethyl 2-(5-bromo-6-methylpyridin-2-yl) -2-[(diphenylmethylidene)amino]acetate (3.2 g, 28% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 437 Synthesis of 11-b: ethyl 2-amino-2-(5-bromo-6-methylpyridin-2-yl)acetate hydrochloride [0312] A solution of ethyl 2-(5-bromo-6-methylpyridin-2-yl)-2- [(diphenylmethylidene)amino]acetate (3.1 g, 7 mmol, 1 equiv) in 4 M HCl solution in ethyl acetate (50 mL) was stirred at room temperature for 4 h. The resulting solids were collected by filtration and dried to afford ethyl 2-amino-2-(5-bromo-6-methylpyridin-2-yl)acetate hydrochloride (1.6 g, 73%) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 273 Synthesis of 11-c: ethyl 6-bromo-5-methylimidazo[1,5-a]pyridine-1-carboxylate [0313] A solution of ethyl 2-amino-2-(5-bromo-6-methylpyridin-2-yl)acetate (1 g , 3.6 mmol, 1 equiv) in triethyl orthoformate (10 mL) was stirred at 90 °C for 2 h. After cooling to room temperature, water (100 mL) was added and the mixture extracted with ethyl acetate (3 x 50 mL). The combined organics were washed with brine (2 x 20 mL) and dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure to give the crude product, which was purified by silica gel chromatography (eluent: PE:EA 1:1) to afford ethyl 6-bromo-5-methylimidazo[1,5-a]pyridine-1-carboxylate (400 mg, 39% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 283 Synthesis of 11-d: ethyl 5-methyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)imidazo[1,5-a] pyridine-1-carboxylate [0314] To a solution of ethyl 6-bromo-5-methylimidazo[1,5-a]pyridine-1-carboxylate (500 mg, 1.7 mmol, 1 equiv) in dioxane (20 mL) were added bis(pinacolato)diboron (896 mg, 3.5 mmol, 2 equiv), KOAc (346 mg, 3.5 mmol, 2 equiv) and Pd(dppf)Cl ₂ (129 mg, 0.17 mmol, 0.1 equiv) at room temperature under nitrogen atmosphere. The resulting mixture was stirred at 100 °C under nitrogen atmosphere for 16 h. After cooling to room temperature, water (100 mL) was added and the mixture extracted with ethyl acetate (3 x 50 mL). The combined organics were washed with brine (2 x 50 mL) and dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure to afford ethyl 5-methyl-6- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5-a]p yridine-1-carboxylate (400 mg, crude) as a brown solid which was used in the next step without further purification. LCMS (ES, m/z): [M+H] ⁺ : 331 Synthesis of 11-e: ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5- [1,5-a]pyridine-1-carboxylate [0315] To a stirred solution of ethyl 5-methyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)imidazo[1,5-a]pyridine-1-carboxylate (300 mg , 0.9 mmol, 1 equiv) in dioxane/H ₂ O (5:1, 12 mL) were added N-(3-bromo-2,4-difluorophenyl)-5-chloro-2-methoxypyridine-3- sulfonamide (450 mg, 1 mmol, 1.2 equiv), K ₂ CO ₃ (314 mg, 2.2 mmol, 2.5 equiv) and SPhos (74 mg, 182 µmol, 0.2 equiv) followed by addition of SPhos Pd G3 (70 mg, 91 µmol, 0.1 equiv) at room temperature under nitrogen atmosphere. The reaction mixture was stirred at 100 °C under nitrogen atmosphere for 16 h. After the mixture was cooled to room temperature, water (100 mL) was added and the mixture extracted with ethyl acetate (3 x 50 mL). The combined organic layers were washed with brine (2 x 50 mL) and dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure to give the crude product, which was purified by silica gel chromatography (eluent: PE:EA 1:1) to afford ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-5- methylimidazo[1,5-a]pyridine-1-carboxylate (200 mg, 41% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 537 Synthesis of Compound 11: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,5-dimethyl imidazo[1,5-a]pyridine-1-carboxamide [0316] To a stirred solution of CH ₃ NH ₂ in MeOH (30%, 5 mL) was added ethyl 6-[3-(5- chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]- 5-methylimidazo[1,5- a]pyridine-1-carboxylate (60 mg, 112 µmol, 1 equiv) at room temperature. The resulting solution was stirred at 80 °C for 16 h. The mixture was concentrated under reduced pressure to give a residue, which was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.1% aqueous formic acid, Mobile Phase B: MeCN (30% - 60% over 15 min) Detector, 220 nm; to afford 6- [3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoroph enyl]-N,5- dimethylimidazo[1,5-a]pyridine-1-carboxamide (50 mg, 64% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 522 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 8.50 (d, J = 2.3 Hz, 2H), 8.21-7.99 (m, 3H), 7.52-7.37 (m, 1H), 7.26 (t, J = 8.9 Hz, 1H), 6.93 (d, J = 9.3 Hz, 1H), 3.94 (s, 3H), 2.84-2.78 (m, 3H), 2.28 (s, 3H). Example 27: Synthesis of 2-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-N-methylimidazo[1,5-b]pyridazine-5-carbo xamide (Compound 12) Synthesis of Compound 12: 2-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-N-methylimidazo[1,5-b]pyridazine-5-carbo xamide [0317] To a stirred mixture of 2-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- b]pyridazine-5-carboxamide (90 mg, 0.3 mmol, 1 equiv) and pyridine (140 mg, 1.8 mmol, 6 equiv) in DCM (3 mL) was added a solution of 5-fluoro-2-methylpyridine-3-sulfonyl chloride (186 mg, 0.9 mmol, 3 equiv) in DCM (1 mL) dropwise at 0 °C. The mixture was stirred overnight at room temperature, then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.1% aqueous formic acid, Mobile Phase B: MeCN (23-43% over 10 min) to afford 2-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-N-methylimidazo[1,5-b]pyridazine-5-carbo xamide (40 mg, 28% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 477 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.86 (s, 1H), 8.86 (s, 1H), 8.74 (d, J = 2.8 Hz, 1H), 8.58 (d, J = 9.4 Hz, 1H), 8.31 (d, J = 5.0 Hz, 1H), 7.96 (dd, J = 8.2, 2.9 Hz, 1H), 7.56-7.42 (m, 1H), 7.31 (t, J = 8.7 Hz, 1H), 7.10 (d, J = 9.4 Hz, 1H), 2.86-2.81 (m, 3H), 2.78 (d, J = 1.2 Hz, 3H). Example 28: Synthesis of 6-[2,6-difluoro-3-[2-methoxy-5-(trifluoromethyl)pyridine-3- sulfonamido]phenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxa mide (Compound 13) Compound 13 Synthesis of 13-a: 3-bromo-2-methoxy-5-(trifluoromethyl)pyridine [0318] Into a 25-mL round-bottom flask, was placed 25% NaOMe in MeOH (10 mL), 3- bromo-2-chloro-5-(trifluoromethyl)pyridine (3 g, 11 mmol, 1 equiv). The resulting solution was stirred for 1 h at 70 °C in an oil bath. The resulting solution was diluted with 10 mL of H ₂ O and extracted with 2x10 mL of dichloromethane. After drying over anhydrous sodium sulfate, the solution was concentrated under reduced pressure to give crude 3-bromo-2- methoxy-5-(trifluoromethyl)pyridine (1.6 g) as yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 256 Synthesis of 130-b: 3-(benzylsulfanyl)-2-methoxy-5-(trifluoromethyl)pyridine [0319] Into a 50 mL round-bottom flask, was placed toluene (32 mL), 3-bromo-2-methoxy-5- (trifluoromethyl)pyridine (1.6 g, 6.3 mmol, 1 equiv), benzyl mercaptan (776 mg, 6.3 mmol, 1 equiv), Pd ₂ (dba) ₃ (286 mg, 0.3 mmol, 0.05 equiv), XantPhos (253 mg, 0.4 mmol, 0.07 equiv) and DIEA (2.4 g, 18.8 mmol, 3 equiv). The resulting solution was stirred for 2 h at 80 °C in an oil bath. The reaction mixture was concentrated under vacuum, and the residue purified by silica gel column chromatography, eluting with PE:EA (10:1) to afford 3-(benzylsulfanyl)-2- methoxy-5-(trifluoromethyl)pyridine (1.5 g, 80% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 300 Synthesis of 13-c: 2-methoxy-5-(trifluoromethyl)pyridine-3-sulfonyl chloride [0320] Into a 50 mL round-bottom flask, was placed CH ₃ CN (30 mL), NCS (2.6 g, 20 mmol, 3 equiv), HCl (1 M) (7 mL) and 3-(benzylsulfanyl)-2-methoxy-5-(trifluoromethyl)pyridine (2 g, 6.7 mmol, 1 equiv). The resulting solution was stirred for 30 min at room temperature, then concentrated under vacuum. The resulting mixture was diluted with 25 mL of H ₂ O and extracted with 2 x 25 mL of ethyl acetate. The combined organics were washed with 20 mL of brine and dried over anhydrous sodium sulfate. Concentration under reduced pressure gave crude 2-methoxy-5-(trifluoromethyl)pyridine-3-sulfonyl chloride (1.4 g) as colorless oil which was used in next step directly without further purification. Synthesis of 13-d: ethyl 6-[2,6-difluoro-3-[2-methoxy-5-(trifluoromethyl)pyridine-3- sulfonamido]phenyl]imidazo[1,5-a]pyridine-1-carboxylate [0321] Into a 25-mL round-bottom flask, was placed ethyl 6-(3-amino-2,6- difluorophenyl)imidazo[1,5-a]pyridine-1-carboxylate (450 mg, 1.4 mmol, 1 equiv), DCM (15 mL), Pyridine (336 mg, 4.3 mmol, 3 equiv) and 2-methoxy-5-(trifluoromethyl)pyridine-3- sulfonyl chloride (391 mg, 1.4 mmol, 1 equiv). The resulting solution was stirred for 30 min at room temperature, then concentrated under vacuum. The residue was diluted with 20 mL of EA and washed with 2 x 20 mL of H ₂ O, then 20 mL of brine. After drying over anhydrous sodium sulfate the solution was concentrated under reduced pressure to give crude ethyl 6- [2,6-difluoro-3-[2-methoxy-5-(trifluoromethyl)pyridine-3-sul fonamido]phenyl]imidazo[1,5- a]pyridine-1-carboxylate (600 mg) as a colorless oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 557 Synthesis of Compound 13: 6-[2,6-difluoro-3-[2-methoxy-5-(trifluoromethyl)pyridine-3- sulfonamido]phenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxa mide [0322] Into a 25-mL round-bottom flask, was placed ethyl 6-[2,6-difluoro-3-[2-methoxy-5- (trifluoromethyl)pyridine-3-sulfonamido]phenyl]imidazo[1,5-a ]pyridine-1-carboxylate (600 mg, 1.1 mmol, 1 equiv) and 33% CH ₃ NH ₂ /EtOH (10 mL). The resulting solution was stirred for 1 h at room temperature. The reaction mixture was concentrated under reduced pressure and the residue was purified by Prep-HPLC with the following conditions: Column: welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.1% aqueous formic acid, Mobile Phase B: MeCN (20-50% over 20 min) to afford 6-[2,6-difluoro-3-[2-methoxy- 5-(trifluoromethyl)pyridine-3-sulfonamido]phenyl]-N-methylim idazo[1,5-a]pyridine-1- carboxamide (39 mg, 7% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 542 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.56 (s, 1H), 8.88 (s, 1H), 8.60 (s, 1H), 8.49 (s, 1H), 8.27 (d, J = 2.4 Hz, 1H), 8.19-8.07 (m, 2H), 7.44-7.33 (m, 1H), 7.27 (d, J = 8.9 Hz, 1H), 6.99 (d, J = 9.4 Hz, 1H), 3.99 (s, 3H), 2.84-2.77 (m, 3H) Example 29: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-fluoro-N- methylimidazo[1,5-a]pyridine-1-carboxamide (Compound 14) Synthesis of 14-a: ethyl 2-(5-bromo-6-fluoropyridin-2-yl)acetate [0323] To a stirred solution of 3-bromo-2-fluoro-6-methylpyridine (6 g, 31.5 mmol, 1 equiv) in THF (79 mL) was added 1 M LiHMDS solution in THF (63 mL, 63 mmol, 2 equiv) dropwise at -78 °C under N ₂ atmosphere. The reaction was stirred at low temperature for 30 min and then diethyl carbonate (5.6 g, 47.4 mmol, 1.5 equiv) was added. The resulting solution was allowed to stir to room temperature for 1 h, then quenched by the addition of H ₂ O (60 mL) at 0 °C. The mixture was extracted with EA (50 mL x 3) and the combined organic layers were dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure and the residue purified by silica gel column chromatography, eluting with PE:EA (20:1) to afford ethyl 2-(5-bromo-6-fluoropyridin-2- yl)acetate (6.6 g, 80% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 262 Synthesis of 14-b: ethyl 2-(5-bromo-6-fluoropyridin-2-yl)-2-diazoacetate [0324] To a stirred solution of ethyl 2-(5-bromo-6-fluoropyridin-2-yl)acetate (4.6 g, 17.5 mmol, 1 equiv) in MeCN (60 mL) was added 4-acetamidobenzenesulfonyl azide (4.4 g, 18.4 mmol, 1.05 equiv) and DBU (2.9 g, 19.3 mmol, 1.1 equiv) at 0 °C. The reaction was stirred at this temperature for 1 h, then diluted with H ₂ O (50 mL), and extracted with EA (50 mL x 3). The combined organics were dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure, and the residue purified by silica gel column chromatography, eluting with PE:EA (10:1) to afford ethyl 2-(5-bromo-6-fluoropyridin-2-yl)- 2-diazoacetate (5 g, 99% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 288 Synthesis of 14-c: ethyl 2-(5-bromo-6-fluoropyridin-2-yl)-2-[(tert- butoxycarbonyl)amino]acetate [0325] To a stirred solution of ethyl 2-(5-bromo-6-fluoropyridin-2-yl)-2-diazoacetate (4.5 g, 15.6 mmol, 1 equiv) in DCE (156 mL) was added tert-butyl carbamate (2.7 g, 23.4 mmol, 1.5 equiv) and Rh ₂ (OAc) ₄ (690 mg, 1.56 mmol, 0.1 equiv) at 0 °C. The reaction was stirred at room temperature for 3 h. The resulting solution was concentrated and the residue was purified by silica gel column chromatography, eluting with PE:EA (10:1) to afford ethyl 2-(5- bromo-6-fluoropyridin-2-yl)-2-[(tert-butoxycarbonyl)amino]ac etate (5.5 g, 93% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 377 Synthesis of 14-d: ethyl 2-amino-2-(5-bromo-6-fluoropyridin-2-yl)acetate [0326] Ethyl 2-(5-bromo-6-fluoropyridin-2-yl)-2-[(tert-butoxycarbonyl)ami no]acetate (7 g) was dissolved in 4 M HCl in 1,4-dioxane (35 mL) and stirred at room temperature for 1 h. The mixture was basified to pH 8 with saturated aqueous NaHCO ₃ , and extracted with DCM (50 mL x 3). The combined organic layers were washed with brine (20 mL) and dried over anhydrous Na ₂ SO ₄ . After filtration, the filtrate was concentrated under reduced pressure to give ethyl 2-amino-2-(5-bromo-6-fluoropyridin-2-yl)acetate (5.4 g, crude) as a red oil which was used in the next step without further purification. LCMS (ES, m/z): [M+H] ⁺ : 277 Synthesis of 14-e: ethyl 2-(5-bromo-6-fluoropyridin-2-yl)-2-formamidoacetate [0327] To a stirred solution of ethyl 2-amino-2-(5-bromo-6-fluoropyridin-2-yl)acetate (3 g, 10.8 mmol, 1 equiv) in THF (54 mL) was added acetic formic anhydride (1.4 g, 16.2 mmol, 1.5 equiv). The reaction was stirred at 60 °C for 1 h, then concentrated. The residue was suspended in DCM (50 mL) and washed with H ₂ O (30 mL x 3). The organic layer was dried over anhydrous Na ₂ SO ₄ , and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (3:1) to afford ethyl 2-(5-bromo-6- fluoropyridin-2-yl)-2-formamidoacetate (2 g, 61% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 305 Synthesis of 14-f: ethyl 6-bromo-5-fluoroimidazo[1,5-a]pyridine-1-carboxylate [0328] Ethyl 2-(5-bromo-6-fluoropyridin-2-yl)-2-formamidoacetate (1 g, 3.3 mmol, 1 equiv) was dissolved in POCl ₃ (10 mL) in a 40 mL vial and stirred at 60 °C for 1 h. The resulting solution was cooled to room temperature and poured onto ice, then extracted with EA (20 mL x 3). The organic layer was dried over anhydrous Na ₂ SO ₄ , and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (5:1) to afford ethyl 6-bromo-5-fluoroimidazo[1,5-a]pyridine-1-carboxylate (0.8 g, 85% yield) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 287 Synthesis of 14-g: 6-bromo-5-fluoroimidazo[1,5-a]pyridine-1-carboxylic acid [0329] To a stirred solution of ethyl 6-bromo-5-fluoroimidazo[1,5-a]pyridine-1-carboxylate (200 mg, 0.77 mmol, 1 equiv) in DMSO (2 mL) and pH 7 buffer (4 mL) was added enzyme catalyst Novozym 435 B (100 mg). The reaction was stirred at 36 °C for 48 h, then filtered. The filtrate was concentrated and the residue purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase, 40-80% MeCN over 20 min / 0.1% aqueous formic acid; Detector, 220 nm; to give 6- bromo-5-fluoroimidazo[1,5-a]pyridine-1-carboxylic acid (86 mg, 48% yield) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 259. Synthesis of 14-h: 6-bromo-5-fluoro-N-methylimidazo[1,5-a]pyridine-1-carboxamid e [0330] To a stirred solution of 6-bromo-5-fluoroimidazo[1,5-a]pyridine-1-carboxylic acid (70 mg, 0.27 mmol, 1 equiv) in DMF (2 mL) was added HATU (123 mg, 0.32 mmol, 1.2 equiv) and DIEA (105 mg, 0.81 mmol, 3 equiv). The reaction was stirred at room temperature for 30 min and then cooled to 0 °C in an ice bath. Methylamine hydrochloride (18 mg, 0.27 mmol, 1 equiv) was added and the resulting solution was stirred at rt for another 30 min. The resulting mixture was diluted with H ₂ O (3 mL), and the aqueous layer extracted with EA (5 mL x 3). The combined organics were concentrated and purified by silica gel column chromatography, eluting with PE:EA (1:2) to afford 6-bromo-5-fluoro-N-methylimidazo[1,5-a]pyridine-1- carboxamide (70 mg, 95% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 272. Synthesis of 14-i: 6-(3-amino-2,6-difluorophenyl)-5-fluoro-N-methylimidazo[1,5- a]pyridine- 1- carboxamide [0331] To a solution of 6-bromo-5-fluoro-N-methylimidazo[1,5-a]pyridine-1-carboxamid e (100 mg, 0.37 mmol, 1 equiv) and 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)aniline (188 mg, 0.74 mmol, 2 equiv) in dioxane (2 mL) and H ₂ O (0.2 mL) were added K ₂ CO ₃ (127 mg, 0.92 mmol, 2.5 equiv), S-Phos (30 mg, 0.074 mmol, 0.2 equiv) and SPhos Pd Gen.3 (29 mg, 0.037 mmol, 0.1 equiv). The reaction was stirred at 100 °C for 2 h under nitrogen atmosphere. The resulting mixture was filtered and the filter cake was washed with dioxane (5 mL). The filtrate was concentrated under reduced pressure and the residue purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C18 10-40 μm, 120 g; mobile phase, 40-80% MeCN over 20 min / 0.1% aqueous formic acid; Detector, 220 nm; to give 6-(3-amino-2,6-difluorophenyl)-5-fluoro-N- methylimidazo[1,5-a]pyridine-1-carboxamide (90 mg, 76% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 321. Synthesis of Compound 14: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-fluoro-N- methylimidazo[1,5-a]pyridine-1-carboxamide [0332] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-5-fluoro-N- methylimidazo[1,5-a]pyridine-1-carboxamide (60 mg, 0.19 mmol, 1 equiv) in DCM (3 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (54 mg, 0.23 mmol, 1.2 equiv) and pyridine (29 mg, 0.38 mmol, 2 equiv). The mixture was stirred at room temperature for 2 days. The solution was concentrated directly and the residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase; Mobile Phase: 30-70% MeCN over 15 min / 0.1% aqueous formic acid; Detector, 220 nm; to give 6-[3-(5-chloro- 2-methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-5-fluor o- N-methylimidazo[1,5-a]pyridine-1-carboxamide (40 mg, 41% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 526. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.51 (s, 1H), 8.67 (d, J = 0.7 Hz, 1H), 8.52 (d, J = 2.6 Hz, 1H), 8.24 (d, J = 4.8 Hz, 1H), 8.08 (d, J = 2.6 Hz, 1H), 8.01 (d, 1H), 7.50-7.44 (m, 1H), 7.36 – 7.26 (m, 1H), 7.18 – 7.07 (m, 1H), 3.91 (s, 3H), 2.82 (d, J = 4.7 Hz, 3H).

Example 30: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-methoxy- N-methylimidazo[1,5-a]pyridine-1-carboxamide (Compound 15) Compound 15 Synthesis of 15-a: 1-(ethoxycarbonyl)-5-fluoroimidazo[1,5-a]pyridin-6-ylboronic acid [0333] To a stirred solution of 6-bromo-5-fluoroimidazo[1,5-a]pyridine-1- carboxylate (1 g, 3.5 mmol, 1 equiv) and bis(pinacolato)diboron (1.8 g, 7 mmol, 2 equiv) in dioxane (18 mL) was added KOAc (684 mg, 7 mmol, 2 equiv) an d Pd(dppf)Cl ₂ (255 mg, 0.35 mmol, 0.1 equiv). After stirring for 1 h at 100 °C under nitrogen atmosphere, the mixture was concentrated, and the residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C18 20-40 μm, 120 g; mobile phase, 5-45% MeCN / 0.1% aqueous formic acid, over 25 min; Detector, 220 nm; to give 1-(ethoxycarbonyl)-5-fluoroimidazo[1,5-a]pyridin-6- ylboronic acid (400 mg, 45% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 253 Synthesis of 15-b: ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5- fluoroimidazo[1,5-a]pyridine-1-carboxylate [0334] To a stirred solution of 1-(ethoxycarbonyl)-5-fluoroimidazo[1,5-a]pyridin-6- ylboronic acid (400 mg, 1.6 mmol, 1 equiv) and N-(3-bromo-2,4-difluorophenyl)-5-chloro-2- methoxypyridine-3-sulfonamide (788 mg, 1.9 mmol, 1.2 equiv) in dioxane (7 mL) and H ₂ O (1.4 mL) were added K ₂ CO ₃ (548 mg, 4 mmol, 2.5 equiv), SPhos Pd Gen.3 (124 mg, 0.16 mmol, 0.1 equiv) and S-Phos (130 mg, 0.32 mmol, 0.2 equiv). After stirring for 2 h at 100 °C under a nitrogen atmosphere, the resulting mixture was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford ethyl 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-5-fluoroi midazo[1,5-a]pyridine-1- carboxylate (80 mg, 9% yield) as a red solid. LCMS (ES, m/z): [M+H] ⁺ : 541 Synthesis of 15-c: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-5- methoxyimidazo[1,5-a]pyridine-1-carboxylic acid [0335] To a stirred solution of ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-fluoroimidazo [1,5-a]pyridine-1-carboxylate (60 mg, 0.11 mmol, 1 equiv) in a mixture of THF (2 mL), MeOH (2 mL) and H ₂ O (1 mL) was added LiOH (8 mg, 0.33 mmol, 3 equiv). The reaction was then stirred at 60 °C for 30 min. The mixture was concentrated under vacuum, and the residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase, 40-70% MeCN / 0.1% aqueous formic acid over 15 min; Detector, 220 nm; to give 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-5- methoxyimidazo[1,5-a]pyridine-1-carboxylic acid (40 mg, 69% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 525 Synthesis of Compound 15: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-methoxy- N-methylimidazo[1,5-a]pyridine-1-carboxamide [0336] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-methoxyimidazo [1,5-a]pyridine-1-carboxylic acid (70 mg, 0.13 mmol, 1 equiv) in MeCN (2 mL) was added TCFH (41 mg, 0.15 mmol, 1.1 equiv), NMI (33 mg, 0.4 mmol, 3 equiv) and CH ₃ NH ₂ .HCl (9 mg, 0.13 mmol, 1 equiv). The reaction was stirred at room temperature for 1 h. The resulting mixture was diluted with H ₂ O (3 mL) and extracted with EA (5 mL x 3). The combined organic layers were dried over anhydrous sodium sulphate and concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.1% aqueous formic acid, Mobile Phase B: MeCN (30-70% over 15 min) Detector, 220 nm; to give 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-methoxy-N-methylimidazo[1,5-a]pyridine-1-c arboxamide (10 mg, 14% yield) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 538. ¹ H NMR (300 MHz, Methanol-d ₄ ) δ 8.39 (s, 1H), 8.37 (d, J = 2.6 Hz, 1H), 8.06 (d, J = 2.6 Hz, 1H), 7.96 (d, J = 9.3 Hz, 1H), 7.66-7.58 (m, 1H), 7.15 (t, J = 8.6 Hz, 1H), 6.94 (d, J = 9.3 Hz, 1H), 4.06 (s, 3H), 3.65 (s, 3H), 2.99 (s, 3H).

Example 31: Synthesis of 3-[3-(5-Chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrimidine-8-carboxami de (Compound 16) Synthesis of 16-a: 2-(5-bromopyrimidin-2-yl)-2-[(diphenylmethylidene)amino]acet ate [0338] Into a 250 mL 3-necked round-bottom flask, was placed 5-bromo-2-chloropyrimidine (10 g, 52 mmol, 1 equiv), ethyl 2-[(diphenylmethylidene)amino]acetate (13.8 g, 52 mmol, 1 equiv), K ₂ CO ₃ (21.4 g, 155 mmol, 3 equiv), Bu ₄ NBr (16.6 g, 52 mmol, 1 equiv) and NMP (100 mL). The resulting solution was stirred for 16 h at 80 °C in an oil bath. The reaction was then quenched by the addition of 100 mL of water/ice. The resulting solution was extracted with 3 x 200 mL of dichloromethane and the organics were washed with 2 x 100 ml of brine. The mixture was dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column, eluting with ethyl acetate/petroleum ether (1:5) to give ethyl 2-(5-bromopyrimidin-2-yl)-2-[(diphenylmethylidene)amino]acet ate (5.5 g, 25% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 424 Synthesis of 16-b: ethyl 2-amino-2-(5-bromopyrimidin-2-yl)acetate [0339] Into a 250 mL 3-necked round-bottom flask, was placed ethyl 2-(5-bromopyrimidin- 2-yl)-2-[(diphenylmethylidene)amino]acetate (5.5 g, 13 mmol, 1 equiv) in DCM (55 mL). This was followed by the addition of HCl (1 M) (10 mL) dropwise with stirring at room temperature. The resulting solution was stirred for 1 hr, then diluted with 100 mL of water. The pH of the solution was adjusted to 8 with NaHCO ₃ (1M), then was extracted with 3 x 50 mL of dichloromethane. The combined organic layers were dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column, eluting with ethyl acetate/petroleum ether (1:5) to give ethyl 2-amino-2-(5-bromopyrimidin- 2-yl)acetate (2.2 g, 65% yield) as a yellow solid. LCMS (ES, m/z): [M+H]+: 260 Synthesis of 16-c: ethyl 3-bromoimidazo[1,5-a]pyrimidine-8-carboxylate [0340] Into a 100 mL 3-necked round-bottom flask, was placed ethyl 2-amino-2-(5- bromopyrimidin-2-yl)acetate (2 g, 7.6 mmol, 1 equiv) and triethyl orthoformate (20 mL). The resulting solution was stirred for 16 h at 110 °C in an oil bath. The mixture was cooled to room temperature and diluted with 10 mL of PE. The solids were collected by filtration and dried to give ethyl 3-bromoimidazo[1,5-a]pyrimidine-8-carboxylate (2.0 g, 96% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 270 Synthesis of 16-d: 8-(ethoxycarbonyl)imidazo[1,5-a]pyrimidin-3-ylboronic acid [0341] Into a 100 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed ethyl 3-bromoimidazo[1,5-a]pyrimidine-8-carboxylate (2 g, 7.4 mmol, 1 equiv), bis(pinacolato)diboron (2.8 g, 11 mmol, 1.5 equiv), dioxane (20 mL), KOAc (1.45 g, 15 mmol, 2 equiv) and Pd(dppf)Cl ₂ (1.08 g, 1.5 mmol, 0.2 equiv). The resulting solution was stirred for 3 hr at 80 °C in an oil bath. The solids were removed by filtration and the filtrate concentrated under vacuum. The crude product was purified by prep- HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 330 g; Mobile Phase: 5% MeCN/0.1% aqueous formic acid; Detector, 220 nm; to give 8- (ethoxycarbonyl)imidazo[1,5-a]pyrimidin-3-ylboronic acid (1.6 g, 92% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 236 Synthesis of 16-e: ethyl 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrimidine-8-carboxylate [0342] Into a 25 mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed 8-(ethoxycarbonyl)imidazo[1,5-a]pyrimidin-3-ylboronic acid (255 mg, 1.9 mmol, 1.5 equiv), N-(3-bromo-2,4-difluorophenyl)-5-chloro-2- methoxypyridine-3-sulfonamide (300 mg, 1.3 mmol, 1 equiv), dioxane (10 mL), H ₂ O (1 mL), K ₂ CO ₃ (200 mg, 2.6 mmol, 2 equiv) and Pd(dppf)Cl ₂ (53 mg, 0.07 mol, 0.1 equiv). The resulting solution was stirred for 3 hr at 80 °C in an oil bath. The reaction mixture was cooled to room temperature and filtered. The filtrate was concentrated under vacuum and the residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; Mobile Phase: 70-95% MeCN over 12 mins / 0.1% aqueous formic acid; Detector, 220 nm. Ethyl 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrimidine-8-carboxylate (150 mg, 39% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 524 Synthesis of 16-f: 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrimidine-8-carboxylic acid [0343] Into an 8 mL round-bottom flask, was placed ethyl 3-[3-(5-chloro-2-methoxypyridine- 3-sulfonamido)-2,6-difluorophenyl]imidazo[1,5-a]pyrimidine-8 -carboxylate (600 mg, 1.1 mmol, 1 equiv), Novozym 435 A(200% SM) and pH 7 buffer (10 mL). The resulting solution was stirred for 24 h at 36 °C. The mixture was filtered and the filtrate concentrated. The residue was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase: Mobile Phase 10-65% MeCN over 12 mins / 0.1% aqueous formic acid; to yield 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrimidine-8-carboxylic acid (200 mg, 35% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 496 Synthesis of Compound 16: 3-[3-(5-Chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrimidine-8-carboxami de [0344] Into a 25 mL round-bottom flask, was placed 3-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]imidazo[1,5-a]pyrimidine-8-c arboxylic acid (200 mg, 0.4 mmol, 1 equiv), DMF (5 mL), HATU (199 mg, 0.5 mmol, 1.3 equiv), DIEA (104 mg, 0.8 mmol, 2 equiv) and methylamine (25.05 mg, 0.8 mmol, 2 equiv). The resulting solution was stirred for 3 hr at room temperature. The reaction was quenched by the addition of 10 mL of water and extracted with 3 x 10 mL of dichloromethane. The combined organics were washed with 1 x 10 ml of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; mobile phase 30-60% MeCN over 15 mins / 0.1% aqueous formic acid; Detector, UV.3-[3-(5-Chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-methylimidazo[1,5-a]pyrim idine-8-carboxamide (105 mg, 51% yield) was obtained as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 509 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.52 (s, 1H), 9.05 (d, J = 2.2 Hz, 1H), 8.52 (d, J = 2.6 Hz, 1H), 8.49-8.39 (m, 2H), 8.10 (d, J = 2.6 Hz, 1H), 8.03 (d, J = 4.9 Hz, 1H), 7.44-7.39 (m, 1H), 7.36-7.27 (m, 1H), 3.94 (s, 3H), 2.85 (d, J = 4.7 Hz, 3H). Example 32: Synthesis of 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-2- methoxy-N-methylimidazo[1,5-a] pyrimidine-8-carboxamide (Compound 17) Synthesis of 17-a: methyl 3-(3-amino-2,6-difluorophenyl)-2- methoxyimidazo[1,5- a]pyrimidine-8-carboxylate [0345] Into a 40 mL vial, purged and maintained with an inert atmosphere of nitrogen, was placed methyl 3-bromo-2-methoxyimidazo[1,5-a]pyrimidine-8-carboxylate (500 mg, 1.7 mmol, 1 equiv), 2,4-difluoro-3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (891 mg, 3.5 mmol, 2 equiv), SphosPdG3 (136 mg, 0.2 mmol, 0.1 equiv), Sphos (143 mg, 0.3 mmol, 0.2 equiv), dioxane (8 mL), H ₂ O (1.6 mL) and K ₂ CO ₃ (724 mg, 5.2 mmol, 3 equiv). The resulting solution was stirred for 2 h at 80 °C in an oil bath. The reaction mixture was cooled and concentrated. The residue was dissolved in 50 mL of DCM and the mixture filtered. The filtrate was dried over anhydrous sodium sulfate and concentrated. The residue was applied onto a silica gel column, eluting with ethyl acetate/petroleum ether (1:1) to give methyl 3-(3-amino-2,6-difluorophenyl)-2-methoxyimidazo[1,5-a]pyrimi dine-8-carboxylate (100 mg, 17% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 335 Synthesis of 17-b: methyl 3-[3-(5-chloro-2-methoxypyridine- 3-sulfonamido)-2,6- difluorophenyl]-2-methoxyimidazo[1,5-a]pyrimidine-8-carboxyl ate [0346] Into an 8 mL vial, was placed methyl 3-(3-amino-2,6-difluorophenyl)-2- methoxyimidazo[1,5-a]pyrimidine-8-carboxylate (70 mg, 0.2 mmol, 1 equiv), DCM (2 mL), pyridine (83 mg, 1 mmol, 5 equiv) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (61 mg, 0.3 mmol, 1.2 equiv). The resulting solution was stirred for overnight at 25 °C. The resulting mixture was concentrated and the crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase 5-60% MeCN over 20 min/0.1% aqueous formic acid; Detector, 220 nm. Methyl 3-[3-(5-chloro-2-methoxypyridine- 3-sulfonamido)-2,6-difluorophenyl]-2- methoxyimidazo[1,5-a]pyrimidine-8-carboxylate (95 mg, 84% yield) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 540 Synthesis of Compound 17: 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-2- methoxy-N-methylimidazo[1,5-a] pyrimidine-8-carboxamide [0347] Into a 50 mL round-bottom flask, was placed methyl 3-[3-(5-chloro-2- methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-2-methoxyimidazo[1,5-a]pyri midine- 8-carboxylate (80 mg, 0.15 mmol, 1 equiv) and 40% aqueous methylamine solution (5 mL). The resulting solution was stirred for overnight at 25 °C and then concentrated. The crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase 33-53% MeCN over 20 min/0.1% aqueous formic acid; Detector, 220 nm; to give 3-[3-(5-chloro-2-methoxypyridine- 3-sulfonamido)-2,6-difluorophenyl]-2-methoxy-N-methylimidazo [1,5-a]pyrimidine-8- carboxamide (38 mg, 48% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 539 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 8.90 (s, 1H), 8.52 (d, J = 2.6 Hz, 1H), 8.18 (s, 1H), 8.08 (d, J = 2.6 Hz, 1H), 7.77 (d, J = 4.9 Hz, 1H), 7.45 (td, J = 8.9, 5.9 Hz, 1H), 7.24 (t, J = 8.9 Hz, 1H), 3.92 (d, J = 2.1 Hz, 6H), 2.83 (d, J = 4.7 Hz, 3H).

Example 33: Synthesis of N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin - 6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (Compound 18) Compound 18 Synthesis of 18-a: N-(2-aminoethyl)-6-bromoimidazo[1,5-a]pyridine-1-carboxamide [0348] Into a 30 mL microwave vial was placed ethyl 6-bromoimidazo[1,5-a]pyridine-1- carboxylate (5 g, 19 mmol, 1 equiv) and ethylenediamine (10 mL). The resulting solution was stirred for 1 h at 130 °C. The resulting mixture was concentrated under vacuum to give N-(2- aminoethyl)-6-bromoimidazo[1,5-a]pyridine-1-carboxamide (2.07 g, crude) as a brown solid, which was used in next step without any purification. LCMS (ES, m/z): [M+H] ⁺ : 283 Synthesis of 18-b: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-4,5-dihydro-1H-imidazo le [0349] Into a 25 mL 3-necked round-bottom flask, was placed N-(2-aminoethyl)-6- bromoimidazo[1,5-a]pyridine-1-carboxamide (2.07 g, 7.3 mmol, 1 equiv) and POCl ₃ (5 mL). The resulting solution was stirred for 30 min at 100 °C, then cooled and concentrated under vacuum. The residue was carefully diluted with 50 mL of H ₂ O and the pH adjusted 8 with saturated aqueous NaHCO ₃ solution. This was extracted with 5 x 100 mL of dichloromethane. The combined organics were dried over anhydrous sodium sulfate and concentrated to give 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-4,5-dihydro-1H-imidazo le (1.0 g, crude) as a brown solid, which was used in next step without any purification. LCMS (ES, m/z): [M+H] ⁺ : 265 Synthesis of 18-c: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1H-imidazole [0350] Into a 25 mL 3-necked round-bottom flask, was placed 2-[6-bromoimidazo[1,5- a]pyridin-1-yl]-4,5-dihydro-1H-imidazole (1 g, 3.8 mmol, 1 equiv), K ₂ CO ₃ (784 mg, 5.7 mmol, 1.5 equiv), PhI(OAc) ₂ (1.83 g, 5.7 mmol, 1.5 equiv) and DMSO (10 mL). The resulting solution was stirred for 3 h at 50 °C in an oil bath, then cooled and diluted with 50 mL of H ₂ O. The resulting solution was extracted with 5 x 50 mL of dichloromethane. The combined organics were dried over anhydrous sodium sulfate and concentrated under vacuum to give 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1H-imidazole (400 mg, crude) as a brown solid, which was used in next step without any purification. LCMS (ES, m/z): [M+H] ⁺ : 263 Synthesis of 18-d: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole [0351] Into a 25 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1H-imidazole (400 mg, 1.52 mmol, 1 equiv) in THF (5 mL). This was followed by the addition of NaH (73 mg, 3 mmol, 2 equiv, 60% in oil) at 0 °C. The suspension was stirred for 15 mins, then SEMCl (380 mg, 2.3 mmol, 1.5 equiv) was added at 0 °C. The resulting solution was stirred for 1 h in an ice/salt bath. The reaction was quenched with 5 mL of H ₂ O and concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE:EA (2:1). Concentration of the relevant fractions afforded 2-[6-bromoimidazo[1,5- a]pyridin-1-yl]-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol e (403 mg, 67% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 393 Synthesis of 18-e: 2-[6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1, 5-a]pyridin- 1-yl]-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole [0352] Into a 25 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (403 mg, 1 mmol, 1 equiv), bis(pinacolato)diboron (390 mg, 1.5 mmol, 1.5 equiv), Pd(dppf)Cl ₂ (75 mg, 0.102 mmol, 0.1 equiv), KOAc (302 mg, 3.1 mmol, 3 equiv) and dioxane (5 mL). The resulting solution was stirred for 2 h at 85 °C in an oil bath. The reaction was quenched by the addition of 50 mL of water, and extracted with 2 x 50 mL of dichloromethane. The combined organics were dried over anhydrous sodium sulfate and concentrated under vacuum to give 2-[6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)imidazo[1,5-a]pyridin-1-yl]-1-[[2-(trimethylsilyl)ethox y]methyl]imidazole (532 mg, crude) as brown oil. LCMS (ES, m/z): [M+H] ⁺ : 441 Synthesis of 18-f: 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imida zol-2- yl)imidazo[1,5-a]pyridin-6-yl]aniline [0353] Into a 25 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 2-[6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)imidazo[1,5-a]pyridin-1-yl]-1-[[2-(trimethylsilyl)ethoxy] methyl]imidazole (380 mg, 0.9 mmol, 1 equiv), 3-bromo-2,4-difluoroaniline (179 mg, 0.9 mmol, 1 equiv), Pd(dppf)Cl ₂ (63 mg, 0.09 mmol, 0.1 equiv), K ₂ CO ₃ (358 mg, 2.6 mmol, 3 equiv), dioxane (10 mL) and H ₂ O (2 mL). The resulting solution was stirred for 2 h at 85 °C in an oil bath then cooled and concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (313 mg, 82% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 442 Synthesis of 18-g: N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide [0354] Into a 25 mL 3-necked round-bottom flask, was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (100 mg, 0.23 mmol, 1 equiv), pyridine (54 mg, 0.68 mmol, 3 equiv) and 5-fluoro-2-methoxypyridine- 3-sulfonyl chloride (51 mg, 0.23 mmol, 1 equiv) in DCM (5 mL). The resulting solution was stirred for 2 h at room temperature, then concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE:EA) to afford N-[2,4-difluoro- 3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imid azo[1,5-a]pyridin-6-yl]phenyl]- 5-fluoro-2-methoxypyridine-3-sulfonamide (83 mg, 58% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 631 Synthesis of Compound 18: N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide [0355] Into a 25 mL 3-necked round-bottom flask, was placed N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (83 mg, 0.13 mmol, 1 equiv) and TFA (3 mL). The resulting solution was stirred for 1 h at 70 °C in an oil bath, then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 25-40% MeCN over 8 min / 0.05% aqueous ammonia; detector, 220 nm. N-[2,4-Difluoro-3-[1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide (29 mg, 42% yield) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 501 1H NMR (300 MHz, DMSO-d6) δ 8.51 (s, 2H), 8.40 (d, J = 3.1 Hz, 1H), 8.22 (d, J = 9.4 Hz, 1H), 7.99 (dd, J = 7.5, 3.1 Hz, 1H), 7.32 (td, J = 8.9, 5.8 Hz, 1H), 7.15 (t, J = 9.3 Hz, 1H), 7.06 (s, 2H), 6.85 (d, J = 9.4 Hz, 1H), 3.89 (s, 3H).

Example 34: Synthesis of N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin - 6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide (Compound 19) Compound 19 Synthesis of 19-a: N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulf onamide [0356] Into a 25 mL round-bottom flask, was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (100 mg, 0.2 mmol, 1 equiv), DCM (10 mL), pyridine (54 mg, 0.7 mmol, 3 equiv) and 5-fluoro-2- methylpyridine-3-sulfonyl chloride (47 mg, 0.2 mmol, 1 equiv). The resulting solution was stirred for 30 min at room temperature, then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE: EA (3:1) to afford N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonami de (93 mg , 67% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 615 Synthesis of Compound 19: N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide [0357] Into a 25 mL round-bottom flask, was placed N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide (93 mg, 0.2 mmol, 1 equiv) and TFA (3 mL). The resulting solution was stirred for 1 h at 70 °C in an oil bath then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 10-50% MeCN over 15 min/ 0.1% aqueous formic acid. N-[2,4-Difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6-yl]phenyl]-5- fluoro-2-methylpyridine-3-sulfonamide (6.6 mg, 9% yield) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 485. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.72 (d, J = 2.9 Hz, 1H), 8.52 (d, J = 4.6 Hz, 2H), 8.22 (d, J = 9.5 Hz, 1H), 8.00-7.91 (m, 1H), 7.41-7.28 (m, 1H), 7.23 (t, J = 9.1 Hz, 1H), 7.10 (s, 2H), 6.82 (d, J = 9.4 Hz, 1H), 2.77 (s, 3H). Example 35: Synthesis of 5-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 20) Compound 20 Synthesis of 20-a: 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0358] Into a 25 mL 3-necked round-bottom flask, was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (100 mg, 0.23 mmol, 1 equiv), DCM (5 mL), pyridine (54 mg, 0.68 mmol, 3 equiv) and 5-cyano-2- methoxypyridine-3-sulfonyl chloride (53 mg, 0.23 mmol, 1 equiv). The resulting solution was stirred for 30 min at room temperature then concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE:EA (20:1) to afford 5-cyano- N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (77 mg, 53% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 638 Synthesis of Compound 20: 5-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0359] Into a 25 mL 3-necked round-bottom flask, was placed 5-cyano-N-[2,4-difluoro-3-[1- (1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1 ,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (77 mg, 0.12 mmol, 1 equiv) and TFA (3 mL). The resulting solution was stirred for 60 min at 70 °C in an oil bath, then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 10-50% MeCN over 15 min / 0.1% aqueous formic acid; Detector 220 nm.5-Cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (24 mg, 37% yield) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 508 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.90 (d, J = 2.2 Hz, 1H), 8.54-8.44 (m, 3H), 8.22 (d, J = 9.4 Hz, 1H), 7.35 (td, J = 9.0, 5.9 Hz, 1H), 7.24-7.12 (m, 1H), 7.07 (s, 2H), 6.84 (dd, J = 9.6, 1.6 Hz, 1H), 4.00 (s, 3H).

Example 36: Synthesis of 7-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-8-fluoro-N-methylimidazo[1,5-a]pyridine-3-ca rboxamide (Compound 21) Compound 21 Synthesis of 21-a: 4-chloro-3-fluoropicolinaldehyde [0360] To a stirred solution of n-BuLi (38 mL, 92 mmol, 1.2 equiv) in THF (100 mL) was added 2,2,6,6-tetramethylpiperidine (13 g, 92 mmol, 1.2 equiv) dropwise at -78 °C under nitrogen atmosphere. The resulting mixture was stirred for 10 min at -78 °C, then 4-chloro-3- fluoropyridine (10 g, 76 mmol, 1 equiv) was added dropwise over 10 min. The resulting mixture was stirred for additional 0.5 h at -78 °C, before DMF (6.1 g, 84 mmol, 1.1 equiv) was added dropwise over 10 min. The resulting mixture was stirred for 0.5 h at -78 °C then quenched by the addition of saturated aqueous NaHCO ₃ solution (50 mL). The resulting mixture was extracted with EA (3 x 100 mL) and the combined organics were washed with brine (1 x 100 mL), then dried over anhydrous sodium sulfate. The solution was concentrated under reduced pressure to give crude 4-chloro-3-fluoropicolinaldehyde (10 g) as a yellow oil, which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 160 Synthesis of 21-b: 4-chloro-3-fluoropicolinaldehydeoxime [0361] A solution of 4-chloro-3-fluoropicolinaldehyde (2.7 g, 17 mmol, 1 equiv), NH ₂ OH.HCl (1.8 g, 25 mmol, 1.5 equiv) and NH ₄ OAc (3.9 g, 50 mmol, 3 equiv) in methanol (20 mL) was stirred for 2 h at room temperature. The reaction mixture was concentrated under reduced pressure. The residue was diluted in water (30 mL) and extracted with EA (3 x 50 mL). The combined organics were washed with brine (50 mL), then dried over anhydrous sodium sulfate before being concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (4:1) to afford 4-chloro-3- fluoropicolinaldehydeoxime (2 g, 67% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 175 Synthesis of 21-c: (4-chloro-3-fluoropyridin-2-yl)methanamine [0362] To a stirred solution of 4-chloro-3-fluoropicolinaldehydeoxime (1.2 g, 6.66 mmol, 1 equiv) and HCOOH (2 g, 33.33 mmol, 5 equiv) in MeOH (10 mL) and H ₂ O (10 mL) was added Zn powder (2.13 g, 33.33 mmol, 5 equiv) in portions at 0 °C. The resulting mixture was stirred for 10 min at 0 °C, then filtered. The filtrate was concentrated under reduced pressure to afford (4-chloro-3-fluoropyridin-2-yl)methanamine (0.91 g) as a brown oil which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 161 Synthesis of 21-d: methyl 2-(((4-chloro-3-fluoropyridin-2-yl)methyl)amino)-2-oxoacetat e [0363] To a stirred solution of (4-chloro-3-fluoropyridin-2-yl)methanamine (911 mg, 5.7 mmol, 1 equiv) and TEA (2.88 g, 28.5 mmol, 5 equiv) in DCM (10 mL) was added methyl oxalochloridate (694 mg, 5.7 mmol, 1 equiv) dropwise at 0 °C. The resulting mixture was stirred for 0.5 h at room temperature, then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (10:1) to afford methyl 2-(((4-chloro-3-fluoropyridin-2-yl)methyl)amino)-2-oxoacetat e (355 mg, 25% yield) as a yellow oil. LCMS (ES, m/z): [M+H]+ : 247 Synthesis of 21-e: methyl 7-chloro-8-fluoroimidazo[1,5-a]pyridine-3-carboxylate [0364] A mixture of methyl 2-(((4-chloro-3-fluoropyridin-2-yl)methyl)amino)-2-oxoacetat e (350 mg, 1.2 mmol, 1 equiv) and POCl ₃ (4 mL) was stirred overnight at 110 °C. The reaction mixture was allowed to cool and was concentrated under reduced pressure. The residue was basified to pH 8 with saturated aqueous NaHCO ₃ and extracted with EA (3 x 5 mL). The combined organics were washed with brine (5 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1:1) to afford methyl 7-chloro-8-fluoroimidazo[1,5- a]pyridine-3-carboxylate (105 mg, 32% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 229 Synthesis of 21-f: methyl 7-(3-amino-2,6-difluorophenyl)-8-fluoroimidazo[1,5-a]pyridin e-3- carboxylate [0365] To a stirred solution of methyl 7-chloro-8-fluoroimidazo[1,5-a]pyridine-3-carboxylate (100 mg, 0.44 mmol, 1 equiv), K ₂ CO ₃ (121 mg, 0.88 mmol, 2 equiv) and 2,4-difluoro-3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (223 mg, 0.88 mmol, 2 equiv) in dioxane (5 mL) were added XPhos (42 mg, 0.088 mmol, 0.2 equiv) and XPhos Pd G3 (37 mg, 0.044 mmol, 0.1 equiv) at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 3 h at 80 °C, then was cooled and quenched with water (10 mL). The resulting solution was extracted with EA (3 x 5 mL). The combined organics were washed with brine (5 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase, 20-70% MeCN over 12 min/0.1% aqueous formic acid; to afford methyl 7-(3-amino-2,6-difluorophenyl)-8-fluoroimidazo[1,5- a]pyridine-3-carboxylate (100 mg, 71% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 322 Synthesis of 21-g: 7-(3-amino-2,6-difluorophenyl)-8-fluoro-N-methylimidazo[1,5- a]pyridine- 3-carboxamide [0366] A mixture of methyl 7-(3-amino-2,6-difluorophenyl)-8-fluoroimidazo[1,5-a]pyridin e- 3-carboxylate (100 mg, 0.31 mmol, 1 equiv), tetrahydrofuran (1 mL) and methylamine solution in water (33%, 4 mL) was stirred for 0.5 h at room temperature. The resulting mixture was extracted with EA (3 x 5 mL). The combined organics were washed with brine (5 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure to give 7-(3-amino-2,6-difluorophenyl)-8-fluoro-N-methylimidazo[1,5- a]pyridine-3-carboxamide (90 mg, crude) as a yellow oil which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 321 Synthesis of Compound 21: 7-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-8-fluoro-N-methylimidazo[1,5-a]pyridine-3-ca rboxamide [0367] To a stirred solution of 7-(3-amino-2,6-difluorophenyl)-8-fluoro-N- methylimidazo[1,5-a]pyridine-3-carboxamide (90 mg, 0.28 mmol, 1 equiv) in pyridine (5 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (102 mg, 0.42 mmol, 1.5 equiv) in portions at room temperature. The resulting mixture was stirred for 0.5 h at room temperature, then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 10-45% MeCN over 10 min/0.1% aqueous formic acid; to afford 7-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-8-fluoro- N-methylimidazo[1,5- a]pyridine-3-carboxamide (40 mg, 27% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 526 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.49 (s, 1H), 9.27 (dd, J = 7.4, 0.9 Hz, 1H), 8.73 (d, J = 4.9 Hz, 1H), 8.48 (s, 1H), 8.07 (d, J = 2.7 Hz, 1H), 7.87 (d, J = 0.8 Hz, 1H), 7.52-7.38 (m, 1H), 7.25 (s, 1H), 6.94 (t, J = 6.9 Hz, 1H), 3.90 (s, 3H), 2.85 (d, J = 4.9 Hz, 3H). Example 37: Synthesis of 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,1-dimethyl-2-oxoimidazo[1,5-a] pyrimidine-8-carboxamide (Compound 22) Synthesis of 22-a: methyl 3-bromo-2-methoxyimidazo [1,5-a]pyrimidine-8-carboxylate [0368] Into a 250 mL 3-necked round-bottom flask, was placed DMF (110 mL). This was followed by the addition of NaH (1.8 g, 44.7 mmol, 2 equiv, 60% in oil), in one portion at -20 °C. To this was added methyl 2-isocyanoacetate (3.3 g, 33.6 mmol, 1.5 equiv) dropwise with stirring at -20 °C. To the mixture was added a solution of 5-bromo-2-chloro-4- methoxypyrimidine (5 g, 22.4 mmol, 1 equiv) in DMF (30 mL) dropwise with stirring at -20 °C. The resulting solution was stirred for 1 h at -20 °C, then quenched with 200 mL of water/ice. The solids formed were collected by filtration and air dried to give methyl 3- bromo-2-methoxyimidazo[1,5-a]pyrimidine-8-carboxylate (2.6 g) as a yellow solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 286 Synthesis of 22-b: 3-bromo-2-hydroxyimidazo[1, 5-a] pyrimidine-8-carboxylic acid [0369] Into a 40 mL vial, was placed methyl 3-bromo-2-methoxyimidazo [1, 5-a] pyrimidine-8- carboxylate (500 mg, 1.75 mmol, 1 equiv), and BBr ₃ (8 mL, 1 M in DCM). The resulting solution was stirred for 1 h at 25 °C before being concentrated. The residue was suspended in 10 mL of water, and the solids collected by filtration and air dried, to give 3- bromo-2-hydroxyimidazo[1, 5-a]pyrimidine-8-carboxylic acid (300 mg) as a brown solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 258 Synthesis of 22-c: methyl 3-bromo-1-methyl-2-oxoimidazo[1,5-a]pyrimidine-8-carboxylate [0370] To a stirred solution of 3-bromo-2-hydroxyimidazo[1,5-a]pyrimidine-8-carboxylic acid (800 mg, 3.1 mmol, 1 equiv) and Cs ₂ CO ₃ (3 g, 9.3 mmol, 3 equiv) in DMF (32 mL) was added CH ₃ I (1.3 g, 9.3 mmol, 3 equiv) dropwise at 0 °C. The resulting mixture was stirred for 3 h at room temperature. The reaction was quenched with water and the precipitated solids were collected by filtration and washed with water (3 x 5 mL), before being dried. Methyl 3- bromo-1-methyl-2-oxoimidazo[1,5-a]pyrimidine-8-carboxylate (490 mg) was isolated as a yellow solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 286 Synthesis of 22-d: methyl 3-(3-amino-2,6-difluorophenyl)-1-methyl-2-oxoimidazo[1,5- a]pyrimidine-8-carboxylate [0371] To a stirred mixture of methyl 3-bromo-1-methyl-2-oxoimidazo[1,5-a]pyrimidine-8- carboxylate (490 mg, 1.7 mmol, 1 equiv) and 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)aniline (874 mg, 3.4 mmol, 2 equiv) in dioxane (10 mL) and H ₂ O (2 mL) were added SphosPdGen.3 (134 mg, 0.17 mmol, 0.1 equiv), Sphos (141 mg, 0.34 mmol, 0.2 equiv) and K ₂ CO ₃ (710 mg, 5.1 mmol, 3 equiv) at room temperature under N ₂ atmosphere. The resulting mixture was stirred for 2 h at 80 °C under N ₂ atmosphere. The mixture was allowed to cool and was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/1) to afford methyl 3-(3-amino-2,6- difluorophenyl)-1-methyl-2-oxoimidazo[1,5-a]pyrimidine-8-car boxylate (300 mg) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 335 Synthesis of 22-e: 3-(3-amino-2,6-difluorophenyl)-1-methyl-2-oxoimidazo[1,5-a]p yrimidine- 8-carboxylic acid [0372] To a stirred solution of methyl 3-(3-amino-2,6-difluorophenyl)-1-methyl-2- oxoimidazo[1,5-a] pyrimidine-8-carboxylate (190 mg, 0.6 mmol, 1 equiv) in DCM (6 mL) was added BBr ₃ (1.2 mL, 1 M in DCM) at room temperature. The resulting mixture was stirred overnight at room temperature, then concentrated under vacuum. The product was precipitated by the addition of water (5 mL) and this was collected by filtration and washed with water (2 x 5 mL). Drying afforded 3-(3-amino-2,6-difluorophenyl)-1-methyl-2- oxoimidazo[1,5-a]pyrimidine-8-carboxylic acid (110 mg) as a yellow solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 321 Synthesis of 22-f: 3-(3-amino-2,6-difluorophenyl)-N,1-dimethyl-2-oxoimidazo[1,5 - a]pyrimidine- 8-carboxamide [0373] Into an 8 mL vial, was placed 3-(3-amino-2,6-difluorophenyl)-1-methyl-2- oxoimidazo[1,5-a]pyrimidine-8-carboxylic acid (100 mg, 0.3 mmol, 1 equiv), DMF (4 mL), HATU (178 mg, 0.5 mmol, 1.5 equiv), DIEA (121 mg, 0.9 mmol, 3 equiv) and methylamine hydrochloride (42 mg, 0.6 mmol, 2 equiv). The resulting solution was stirred for 3 h at 25 °C, then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; mobile phase, 5-60% MeCN over 20 mins / 0.1% aqueous formic acid; Detector, 254 nm.3-(3-Amino-2,6- difluorophenyl)-N,1-dimethyl-2-oxoimidazo[1,5-a]pyrimidine- 8-carboxamide (60 mg) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ :334 Synthesis of Compound 22: 3-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,1-dimethyl-2-oxoimidazo[1,5-a] pyrimidine-8-carboxamide [0374] Into an 8 mL vial, was placed 3-(3-amino-2,6-difluorophenyl)-N,1-dimethyl-2- oxoimidazo[1,5-a] pyrimidine-8-carboxamide (30 mg, 0.1 mmol, 1 equiv), DCM (2 mL), pyridine (36 mg, 0.45 mmol, 5 equiv) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (26 mg, 0.1 mmol, 1.2 equiv). The resulting solution was stirred overnight at 25 °C, then concentrated. The crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; mobile phase, 33-53% MeCN over 8 mins / 0.1% aqueous formic acid; Detector, 254 nm.3-[3-(5-Chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N,1-dimethyl-2-oxoimidazo[1 ,5-a] pyrimidine-8- carboxamide (15.6 mg) was isolated as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 539 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.48 (s, 1H), 8.65 (s, 1H), 8.48 (d, J = 2.6 Hz, 1H), 8.22- 8.11 (m, 1H), 8.07 (d, J = 2.6 Hz, 1H), 8.00 (s, 1H), 7.37 (td, J = 8.9, 5.9 Hz, 1H), 7.16 (t, J = 8.9 Hz, 1H), 3.88 (d, J = 9.3 Hz, 6H), 2.77 (d, J = 4.8 Hz, 3H). Example 38: Synthesis of 6-[3-[3-cyano-5-(trifluoromethyl)benzenesulfonamido]-2,6- difluorophenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide (Compound 23) Compound 23 Synthesis of Compound 23: 6-[3-[3-cyano-5-(trifluoromethyl)benzenesulfonamido]-2,6- difluorophenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide [0375] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyridine-1-carboxamide (100 mg, 0.33 mmol, 1 equiv) and 3-cyano-5- (trifluoromethyl)benzenesulfonyl chloride (178 mg, 0.66 mmol, 2 equiv) in DCM (5 ml) was added pyridine (52 mg, 0.66 mmol, 2 equiv) at 0 °C, and the reaction was stirred at room temperature overnight. The reaction was concentrated and the residue purified by prep- HPLC using the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 20-60% MeCN over 15 min/ 0.1% aqueous formic acid; to give 6-[3-[3- cyano-5-(trifluoromethyl)benzenesulfonamido]-2,6-difluorophe nyl]-N-methylimidazo[1,5- a]pyridine-1-carboxamide (30 mg, 17% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 536 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.69 (s, 1H), 8.72 (s, 1H), 8.58 (s, 1H), 8.49 (d, J = 4.5 Hz, 2H), 8.28 (s, 1H), 8.15-8.08 (m, 2H), 7.34-7.22 (m, 2H), 6.97 (d, J = 9.4 Hz, 1H), 2.81 (d, J = 4.3 Hz, 3H). Example 39: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methyl-5- (methylamino)imidazo[1,5-a]pyridine-1-carboxamide (Compound 24) Synthesis of Compound 24: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methyl-5- (methylamino)imidazo[1,5-a]pyridine-1-carboxamide [0376] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-fluoro-N-methylimidazo[1,5-a]pyridine-1-ca rboxamide (80 mg, 0.15 mmol, 1 equiv) in THF (1 mL) was added 40% aqueous CH ₃ NH ₂ (14 mg, 0.45 mmol, 3 equiv), and the reaction was stirred at room temperature overnight. The solution was concentrated directly and the residue was purified by prep-HPLC using the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 30-70% MeCN over 15 mins / 0.1% aqueous formic acid; Detector, 220 nm.6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-methyl- 5- (methylamino)imidazo[1,5-a]pyridine-1-carboxamide (40 mg, 49% yield) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 537 1H NMR (300 MHz, Methanol-d4) δ 8.41-8.32 (m, 2H), 8.03 (d, J = 2.6 Hz, 1H), 7.64 (dd, J = 9.2, 0.8 Hz, 1H), 7.55 (td, J = 8.9, 5.8 Hz, 1H), 7.08 (td, J = 8.8, 1.9 Hz, 1H), 6.79 (d, J = 9.2 Hz, 1H), 4.07 (s, 3H), 2.98 (s, 3H), 2.37 (s, 3H). Example 40: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide (Compound 25) Compound 25 Synthesis of 25-a: 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide [0377] Into a 25 mL 3-necked round-bottom flask, was placed DCM (5 mL), 2,4-difluoro-3- [1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidaz o[1,5-a]pyridin-6-yl]aniline (100 mg, 0.2 mmol, 1 equiv), pyridine (54 mg, 0.6 mmol, 3 equiv) and 5-chloro-2- methylpyridine-3-sulfonyl chloride (51 mg, 0.2 mmol, 1 equiv). The resulting solution was stirred for 2 h at room temperature. The mixture was concentrated under reduced pressure and the residue purified by silica gel column chromatography, eluting with PE:EA (3:2) to afford 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy] methyl]imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sul fonamide (83 mg, 58% yield) as yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 631 Synthesis of Compound 25: 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide [0378] Into a 25 mL 3-necked round-bottom flask, was placed 5-chloro-N-[2,4-difluoro-3-[1- (1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1 ,5-a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (83 mg, 0.1 mmol, 1 equiv) and TFA (3 mL). The resulting solution was stirred for 1 h at 70 °C in an oil bath, then cooled and concentrated. The residue was purified by prep-HPLC with the following conditions Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 5-40% MeCN over 15 min/ 0.1% aqueous formic acid; 5-Chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (15 mg, 21% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 501 ¹ H NMR (300 MHz, Methanol-d ₄ ) δ 8.65 (d, J = 2.4 Hz, 1H), 8.46 (d, J = 11.3 Hz, 2H), 8.20-8.09 (m, 2H), 7.54 (td, J = 8.9, 5.6 Hz, 1H), 7.32 (s, 2H), 7.24-7.11 (m, 1H), 6.98 (d, J = 9.4 Hz, 1H), 2.85 (s, 3H). Example 41: Synthesis of 5-chloro-N-[3,5-difluoro-4-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]pyridin-2-yl]-2-methoxypyridine-3-sulfonamide (Compound 26) Compound 26 Synthesis of 26-a: 3,5-difluoro-4-iodopyridin-2-amine [0379] To a stirred solution of 3,5-difluoropyridin-2-amine (5 g, 38 mmol, 1 equiv) in THF (200 mL) was added LDA (61 mL, 123 mmol, 3 equiv) dropwise at -78 °C under N ₂ atmosphere. The solution was stirred for 1.5 h at -78 °C. To the resulting mixture was added a solution of I ₂ (34 g, 135 mmol, 3.5 equiv) in THF (50 mL) dropwise at -78 °C. This mixture was stirred for additional 0.5 h at -78 °C, then was quenched with saturated aqueous Na ₂ S ₂ O ₃ (100 mL). The reaction was extracted with EA (3 x 50 mL), and the combined organics were washed with brine (2 x 50 mL) and dried over anhydrous sodium sulfate before being concentrated. The residue was purified by silica gel column chromatography, eluting with PE:EA (3:1) to afford 3,5-difluoro-4-iodopyridin-2- amine (7.8 g, 79% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 257 Synthesis of 26-b: 5-chloro-N-(3,5-difluoro-4-iodopyridin-2-yl)-2-methoxypyridi ne-3- sulfonamide [0380] Into a 50 mL round-bottom flask was placed 3,5-difluoro-4-iodopyridin-2-amine (100 mg, 0.4 mmol, 1 equiv), pyridine (2 mL) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (142 mg, 0.6 mmol, 1.5 equiv). The resulting solution was stirred for 12 h at 50 °C in an oil bath. The resulting mixture was washed with 3 x 6 mL of H ₂ O, then was extracted with 2 x 6 mL of dichloromethane. The combined organics were dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE:EA (3:1) to afford 5-chloro-N-(3,5-difluoro-4-iodopyridin- 2-yl)-2-methoxypyridine-3-sulfonamide (90 mg, 50% yield) as light yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 462 Synthesis of 26-c: 5-chloro-N-[3,5-difluoro-4-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]pyridin-2-yl]-2- methoxypyridine-3-sulfonamide [0381] Into a 50 mL round-bottom flask was placed 2-[6-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)imidazo[1,5-a]pyridin-1-yl]-1-[[2-(trimeth ylsilyl)ethoxy]methyl]imidazole (45 mg, 0.1 mmol, 1 equiv), dioxane (2 mL), 5-chloro-N-(3,5-difluoro-4-iodopyridin-2-yl)-2- methoxypyridine-3-sulfonamide (47 mg, 0.1 mmol, 1 equiv), Pd(dppf)Cl ₂ (5 mg, 0.007 mmol, 0.07 equiv), K ₂ CO ₃ (42 mg, 0.3 mmol, 3 equiv) and H ₂ O (0.5 mL). The resulting solution was stirred for 2 h at 85 °C in an oil bath. The resulting mixture was washed with 2 x 6 mL of H ₂ O, then extracted with 2 x 6 mL of dichloromethane. The combined organics were dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE:EA (3:1) to afford 5-chloro-N- [3,5-difluoro-4-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imid azol-2-yl)imidazo[1,5-a]pyridin- 6-yl]pyridin-2-yl]-2-methoxypyridine-3-sulfonamide (60 mg, 91% yield) as a light yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 648 Synthesis of Compound 26: 5-chloro-N-[3,5-difluoro-4-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]pyridin-2-yl]-2-methoxypyridine-3-sulfonamide [0382] Into a 50 mL round-bottom flask was placed 5-chloro-N-[3,5-difluoro-4-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]pyridin-2-yl]-2- methoxypyridine-3-sulfonamide (50 mg, 0.1 mmol, 1 equiv) and TFA (2 mL). The resulting solution was stirred for 1 h at 70 °C in an oil bath, then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 5-35% MeCN over 15 mins/0.1% aqueous formic acid; to afford 5-chloro-N-[3,5-difluoro-4-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]pyridin-2-yl]-2-methoxypyridine-3-sulfonamide (3 mg, 6.8% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 518 ¹ H NMR (300 MHz, Methanol-d ₄ ) δ 8.80 (s, 1H), 8.65 (s, 1H), 8.44-8.36 (m, 1H), 8.35-8.28 (m, 1H), 8.24-8.11 (m, 2H), 7.58 (s, 2H), 7.40 (d, J = 9.3 Hz, 1H), 4.06 (d, J = 1.3 Hz, 3H).

Example 42: Synthesis of (6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine- 1-carboxamide & (6S)- 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (Compound 27-1 and 27-2) Synthesis of 27-a: 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5-a]pyridin e-1- carboxamide [0383] To a stirred mixture of ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine- 1-carboxylate (2 g, 6.3 mmol, 1 equiv) in THF (10 mL) was added 40% methylamine solution in water (20 mL) at room temperature. The resulting solution was stirred for 12 hours at 80 °C. The mixture was allowed to cool to room temperature and concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20- 70% MeCN/0.1% NH ₄ HCO ₃ and 0.05% NH ₃ ·H ₂ O; to give 6-(3-amino-2,6-difluorophenyl)- N-methylimidazo[1,5-a]pyridine-1-carboxamide (1.6 g, 83% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 303 Synthesis of 27-b: 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,7H,8H-imidazo[ 1,5- a]pyridine-1-carboxamide [0384] To a solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5-a]pyridin e-1- carboxamide (750 mg, 2.5 mmol, 1 equiv) in EtOH (25 mL) was added Pd/C (10%, 0.8 g) in a pressure tank. The mixture was hydrogenated at 80 °C under 20 atm of hydrogen pressure for 5 hours, then filtered through a Celite pad and concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g, mobile phase: 20-70% MeCN/0.1% NH ₄ HCO ₃ & 0.05% NH ₃ ·H ₂ O; to give 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (280 mg, 36% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 307 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 7.75 (d, J = 5.0 Hz, 1H), 7.56 (s, 1H), 6.81 (ddd, J = 10.3, 8.9, 1.4 Hz, 1H), 6.70 (td, J = 9.3, 5.7 Hz, 1H), 5.03 (s, 2H), 4.32 (dd, J = 12.2, 5.3 Hz, 1H), 4.08 (t, J = 12.0 Hz, 1H), 3.44-3.27 (m, 1H), 3.32 (s, 1H), 2.88 (ddd, J = 17.8, 11.8, 6.2 Hz, 1H), 2.72 (d, J = 4.7 Hz, 3H), 2.19 (s, 1H), 2.05 (s, 1H). Synthesis of Compounds 27-1 and 27-2: (6R)-6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-methyl-5H,6H,7H,8H-imidaz o[1,5-a]pyridine-1- carboxamide & (6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]- N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide [0385] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (200 mg, 0.65 mmol, 1 equiv) and pyridine (310 mg, 3.92 mmol, 6 equiv) in DCM (6 mL) was added a solution of 5-chloro-2-methoxypyridine-3- sulfonyl chloride (238 mg, 0.98 mmol, 1.5 equiv) in DCM (2 mL) dropwise at 0 °C. The resulting solution was stirred for 2.5 hours, then concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm mobile phase, Mobile Phase A: 0.1% FA in Water, Mobile Phase B: MeCN (10% up to 30% in 10 min) and chiral separation with the following conditions: Column, CHIRALPAK IF, 20 x 250 mm, 5 µm, Mobile Phase A: Hexane: DCM (3:1). Mobile phase B: EtOH (10% up to 30% in 15 min) to give (6R)-6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5- a]pyridine-1-carboxamide (25 mg, 7.5% yield) as a white solid and (6S)-6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5- a]pyridine-1-carboxamide (21 mg, 6% yield) as a white solid. Stereochemistry was randomly assigned. Compound 27-1 LCMS (ES, m/z): [M+H] ⁺ : 512 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.33 (s, 1H), 8.52 (d, J = 2.6 Hz, 1H), 8.02 (d, J = 2.6 Hz, 1H), 7.74 (d, J = 5.0 Hz, 1H), 7.55 (s, 1H), 7.26 (td, J = 8.8, 5.7 Hz, 1H), 7.11 (t, J = 9.5 Hz, 1H), 4.26 (dd, J = 12.3, 5.2 Hz, 1H), 4.00 (d, J = 11.9 Hz, 1H), 3.92 (s, 3H), 3.49 (s, 1H), 2.87 (ddd, J = 17.8, 11.6, 6.3 Hz, 1H), 2.72 (d, J = 4.8 Hz, 3H), 2.07 (d, J = 9.0 Hz, 1H), 1.97 (s, 2H). Compound 27-2 LCMS (ES, m/z): [M+H] ⁺ : 512 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.33 (s, 1H), 8.52 (d, J = 2.6 Hz, 1H), 8.02 (d, J = 2.6 Hz, 1H), 7.74 (d, J = 5.0 Hz, 1H), 7.55 (s, 1H), 7.33-7.19 (m, 1H), 7.11 (t, J = 9.5 Hz, 1H), 4.26 (dd, J = 12.3, 5.2 Hz, 1H), 4.00 (d, J = 11.9 Hz, 1H), 3.93 (s, 3H), 3.49 (s, 1H), 2.87 (ddd, J = 17.9, 11.8, 6.3 Hz, 1H), 2.72 (d, J = 4.7 Hz, 3H), 2.07 (d, J = 12.3 Hz, 1H), 1.97 (s, 2H). Example 43: Synthesis of N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin - 6-yl]phenyl]-6-fluoro-1-hydroxy-2,3-dihydro-1H-indene-4-sulf onamide (Compound 28) Compound 28 Synthesis of 28-a: 4-([2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridi n-6- yl]phenyl]sulfamoyl)-6-fluoro-2,3-dihydro-1H-inden-1-yl acetate [0386] Into a 50 mL round-bottom flask was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (90 mg, 0.2 mmol, 1 equiv), pyridine (4 mL) and 4-(chlorosulfonyl)-6-fluoro-2,3-dihydro-1H-inden-1-yl acetate (71 mg, 0.2 mmol, 1 equiv). The resulting solution was stirred for 1 h at room temperature. The resulting mixture was diluted with H ₂ O (10 mL) and was extracted with dichloromethane (2 x 6 mL). The combined organics were washed with H ₂ O (2 x 6 mL), then dried over anhydrous sodium sulfate. Concentration gave the crude product, which was purified by silica gel column chromatography, eluting with PE:EA (3:2) to afford 4-([2,4- difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]p henyl]sulfamoyl)-6-fluoro-2,3- dihydro-1H-inden-1-yl acetate (80 mg, 69% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 568. Synthesis of Compound 28: N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6- yl]phenyl]-6-fluoro-1-hydroxy-2,3-dihydro-1H-indene-4-sulfon amide [0387] Into a 50 mL round-bottom flask was placed 4-([2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]sulfamoyl)- 6-fluoro-2,3-dihydro-1H-inden-1-yl acetate (70 mg, 0.1 mmol, 1 equiv) and TBAF (1 mol/L in THF, 1 mL). The resulting solution was stirred for 12 h at 65 °C in an oil bath, then cooled and diluted with H ₂ O (10 mL). The resulting mixture was extracted with dichloromethane (2 x 10 mL). The combined organics were washed with H ₂ O (2 x 6 mL), then dried over anhydrous sodium sulfate. Concentration gave the crude product which was purified by prep- HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 20-40% MeCN/ 0.1% aqueous formic acid; to afford N-[2,4-difluoro-3-[1- (1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-6-fluor o-1-hydroxy-2,3-dihydro-1H- indene-4-sulfonamide (5.5 mg, 10% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 526. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.37 (br s, 1H), 8.48 (m, 2H), 8.25-8.13 (m, 2H), 7.34 (d, J = 8.8 Hz, 2H), 7.30-7.19 (m, 1H), 7.0-7.14 (m, 3H), 6.81 (d, J = 9.4 Hz, 1H), 5.53 (d, J = 4.9 Hz, 1H), 5.04 (d, J = 6.0 Hz, 1H), 3.09 (m, 1H), 2.81 (m, 1H), 2.33 (m, 1H), 1.73 (dt, J = 14.9, 7.5 Hz, 1H). Example 44: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 29) Compound 29 Synthesis of 29-a: 6-bromoimidazo[1,5-a]pyridine-1-carboxamide [0388] Into a 30 mL sealed tube was placed ethyl 6-bromoimidazo[1,5-a]pyridine-1- carboxylate (500 mg, 1.9 mmol, 1 equiv), MeOH (5 mL) and NH ₃ .H ₂ O (5 mL). The resulting solution was stirred for 36 h at 100 °C in an oil bath, then concentrated under vacuum to give 6-bromoimidazo[1,5-a]pyridine-1-carboxamide (360 mg, 61% yield) as a brown solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 240 Synthesis of 29-b: 6-bromo-N-[(1Z)-(dimethylamino)methylidene]imidazo[1,5-a]pyr idine-1- carboxamide [0389] Into a 25 mL 3-necked round-bottom flask was placed 6-bromoimidazo[1,5- a]pyridine-1-carboxamide (360 mg, 1.5 mmol, 1 equiv) and DMF-DMA (4 mL). The resulting solution was stirred for 1 h at 80 °C in an oil bath. After cooling, the solids were collected by filtration and dried to give 6-bromo-N-[(1Z)- (dimethylamino)methylidene]imidazo[1,5-a]pyridine-1-carboxam ide(167 mg, 33% yield) as a grey solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 295 Synthesis of 29-c: 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-4H-1,2,4-triazole [0390] Into a 25 mL 3-necked round-bottom flask was placed 6-bromo-N- [(dimethylamino)methylidene]imidazo[1,5-a]pyridine-1-carboxa mide (167 mg, 0.56 mmol, 1 equiv), AcOH (2 mL) and NH ₂ NH ₂ .H ₂ O (2 mL). The resulting solution was stirred for 1 h at 90 °C in an oil bath, then concentrated under vacuum. The resulting solution was diluted with H ₂ O (15 mL). The solution was adjusted to pH 7~8 with saturated NaHCO ₃ and was then extracted with dichloromethane (3 x 15 mL). The combined organics were dried over anhydrous sodium sulfate and concentrated under vacuum to give 3-[6-bromoimidazo[1,5- a]pyridin-1-yl]-4H-1,2,4-triazole(120 mg, crude) as a yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 264 Synthesis of 29-d: 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazole [0391] Into a 25 mL 3-necked round-bottom flask was placed 3-[6-bromoimidazo[1,5- a]pyridin-1-yl]-4H-1,2,4-triazole (120 mg, 0.45 mmol, 1 equiv) in THF (5 mL). This was followed by the addition of 60% NaH (37 mg, 0.9 mmol, 2 eq), in portions at 0 °C. To this was added SEM-Cl (114 mg, 0.68 mmol, 1.5 equiv) dropwise with stirring at 0 °C. The resulting solution was stirred for 1 h at 0 °C in an ice/salt bath. The reaction was then quenched by the addition of water (20 mL) and the resulting solution was extracted with dichloromethane (3 x 20 mL). The combined organics were washed with brine (50 ml), dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied to a silica gel column, eluting with THF:PE (1:1) to give 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]- 4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazole (125 mg, 59% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 394 Synthesis of 29-e: 3-[6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1, 5-a]pyridin- 1-yl]-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazole [0392] Into a 25 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazole (125 mg, 0.32 mmol, 1 equiv), bis(pinacolato)diboron (121 mg, 0.5 mmol, 1.5 equiv), Pd(dppf)Cl ₂ (23 mg, 0.03 mmol, 0.1 equiv), KOAc (93 mg, 0.95 mmol, 3 equiv) and dioxane (5 mL). The resulting solution was stirred for 2 h at 85 °C in an oil bath, then cooled and diluted with DCM (20 mL). The mixture was washed with H ₂ O (2 x 20 ml) and brine (20 mL), then dried over anhydrous sodium sulfate and concentrated under vacuum.3-[6-(4,4,5,5-Tetramethyl-1,3,2- dioxaborolan-2-yl)imidazo[1,5-a]pyridin-1-yl]-4-[[2-(trimeth ylsilyl)ethoxy]methyl]-1,2,4- triazole (200 mg, crude) was isolated as a brown oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 442 Synthesis of 29-f: 2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2, 4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]aniline [0393] Into a 25 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 3-[6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)imidazo[1,5-a]pyridin-1-yl]-4-[[2-(trimethylsilyl)ethoxy] methyl]-1,2,4-triazole (200 mg, 0.45 mmol, 1 equiv), 3-bromo-2,4-difluoroaniline (94 mg, 0.45 mmol, 1 equiv), Pd(dppf)Cl ₂ (33 mg, 0.045 mmol, 0.1 equiv), K ₂ CO ₃ (188 mg, 1.4 mmol, 3 equiv), H ₂ O (2 mL) and dioxane (10 mL). The resulting solution was stirred for 2 h at 85 °C in an oil bath, then concentrated under vacuum. The residue was applied to a silica gel column, eluting with THF:PE (35:65).2,4-Difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]meth yl]-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]aniline (100 mg, 50% yield) was obtained as yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 443 Synthesis of 29-g: 5-chloro-N-[2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy] methyl]-1,2,4- triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyr idine-3-sulfonamide [0394] Into a 25 mL 3-necked round-bottom flask was placed 2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]aniline (100 mg, 0.23 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (55 mg, 0.23 mmol, 1 equiv) and pyridine (3 mL). The resulting solution was stirred for 1 h at 50 °C in an oil bath, then cooled and concentrated under vacuum. The residue was applied to a silica gel column, eluting with THF:PE (3:7).5-Chloro-N-[2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide(87 mg, 80% yield) was obtained as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 648 Synthesis of Compound 29: 5-chloro-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0395] Into a 25 mL 3-necked round-bottom flask was placed 5-chloro-N-[2,4-difluoro-3-[1- (4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imi dazo[1,5-a]pyridin-6-yl]phenyl]- 2-methoxypyridine-3-sulfonamide (87 mg, 0.14 mmol, 1 equiv) and TFA (2 mL). The resulting solution was stirred for 30 min at 50 °C in an oil bath, then was cooled and concentrated under vacuum. The resulting solution was diluted with EA (15 mL), and the pH adjusted to 7~8 with saturated NaHCO ₃ /H ₂ O. The resulting solution was extracted with ethyl acetate (10 mL) and the combined organics dried over anhydrous sodium sulfate, then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; mobile phase: 35-70% MeCN/ 0.1% aqueous formic acid; Detector, 220 nm.5-Chloro-N-[2,4-difluoro-3-[1- (4H-1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (14.2 mg, 19% yield) was isolated as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 518 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 14.33 (s, 1H), 10.49 (s, 1H), 8.56 (d, J = 35.8 Hz, 3H), 8.22 (d, J = 9.5 Hz, 1H), 8.09 (s, 1H), 8.02 (s, 1H), 7.37 (q, J = 7.7 Hz, 1H), 7.26 (d, J = 9.2 Hz, 1H), 7.01 (t, J = 5.7 Hz, 1H), 3.92 (s, 3H).

Example 45: Synthesis of 7-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyridine-3-carboxamide (Compound 30) Compound 30 Synthesis of 30-a: N-[(4-chloropyridin-2-yl)methylidene]hydroxylamine [0396] A solution of 4-chloropyridine-2-carbaldehyde (5 g, 35 mmol, 1 equiv), NH ₂ OH·HCl (3.7 g, 53 mmol, 1.5 equiv) and NH ₄ OAc (8.2 g, 106 mmol, 3 equiv) in CH ₃ OH (50 mL) was stirred for 2 h at room temperature. The resulting mixture was concentrated under reduced pressure. The residue was suspended in H ₂ O (50 mL), and the mixture basified to pH 8 with saturated aqueous NaHCO ₃ . The resulting mixture was extracted with EA (3 x 50 mL). The combined organics were washed with brine (100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure to afford N-[(4-chloropyridin-2- yl)methylidene]hydroxylamine (5.3 g, 94% yield) as a white solid which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 157 Synthesis of 30-b: 1-(4-chloropyridin-2-yl)methanamine [0397] To a stirred solution of N-[(4-chloropyridin-2-yl)methylidene]hydroxylamine (5.3 g, 34 mmol, 1 equiv) and HCOOH (7.7 g, 168 mmol, 5 equiv) in CH ₃ OH (25 mL) and H ₂ O (25 mL) were added Zn powder (11 g, 168 mmol, 5 equiv) in portions at 0 °C. The resulting mixture was stirred for 1 h at 0 °C, then filtered. The filtrate was concentrated under reduced pressure to afford 1-(4-chloropyridin-2-yl)methanamine (5.7 g, crude) as a brownish yellow oil which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 143 Synthesis of 30-c: methyl [[(4-chloropyridin-2-yl)methyl]carbamoyl]formate [0398] To a stirred solution of 1-(4-chloropyridin-2-yl)methanamine (5.2 g, 36 mmol, 1 equiv) and TEA (18.5 g, 182 mmol, 5 equiv) in DCM (50 mL) was added methyl oxalochloridate (4.5 g, 36 mmol, 1 equiv) dropwise at 0 °C. The resulting mixture was stirred for 0.5 h at room temperature, then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (10:1) to afford methyl [[(4-chloropyridin-2-yl)methyl]carbamoyl]formate (2.9 g, 35% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 229 Synthesis of 30-d: methyl 7-chloroimidazo[1,5-a]pyridine-3-carboxylate [0399] A solution of methyl [[(4-chloropyridin-2-yl)methyl]carbamoyl]formate (2.9 g, 13 mmol, 1 equiv) in POCl ₃ (10 mL) was stirred overnight at 120 °C. The mixture was allowed to cool to room temperature and was concentrated under reduced pressure. The residue was quenched by the addition of H ₂ O (50 mL) at 5 °C. The resulting mixture was extracted with EA (3 x 20 mL), and the combined organics were washed with brine (1 x 30 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford methyl 7- chloroimidazo[1,5-a]pyridine-3-carboxylate (0.7 g, 26% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 211 Synthesis of 30-e: methyl 7-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine-3- carboxylate [0400] To a stirred solution of methyl 7-chloroimidazo[1,5-a]pyridine-3-carboxylate (190 mg, 0.9 mmol, 1 equiv) and 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)aniline (460 mg, 1.8 mmol, 2 equiv) in dioxane (2 mL) and H ₂ O (0.2 mL) were added K ₂ CO ₃ (187 mg, 1.4 mmol, 1.5 equiv), Sphos (74 mg, 0.18 mmol, 0.2 equiv) and SPhos Pd G3 (70 mg, 0.09 mmol, 0.1 equiv) in portions at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 3 h at 90 °C, then cooled and quenched with water (10 mL). The resulting mixture was extracted with EA (3 x 20 mL), and the combined organics washed with brine (10 mL), then dried over anhydrous Na ₂ SO ₄ . Concentration afforded a residue which was purified by silica gel column chromatography, eluting with PE: EA (3:1) to afford methyl 7-(3-amino-2,6-difluorophenyl)imidazo[1,5- a]pyridine-3-carboxylate (210 mg, 77% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 304 Synthesis of 30-f: 7-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5-a]pyridin e-3- carboxamide [0401] A solution of methyl 7-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine-3- carboxylate (100 mg, 0.33 mmol, 1 equiv) in tetrahydrofuran (1.0 mL) and 30% aqueous CH ₃ NH ₂ (1.0 mL) was stirred for 0.5 h at room temperature. The reaction mixture was concentrated under reduced pressure to afford 7-(3-amino-2,6-difluorophenyl)-N- methylimidazo[1,5-a]pyridine-3-carboxamide (100 mg, crude) as a yellow oil which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 303 Synthesis of Compound 30: 7-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyridine-3-carboxamide [0402] To a stirred solution of 7-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyridine-3-carboxamide (100 mg, 0.33 mmol, 1 equiv) in pyridine (2 mL) was added a solution of 5-chloro-2-methoxypyridine-3-sulfonyl chloride (96 mg, 0.4 mmol, 1.2 equiv) in DCM (1 mL) dropwise at 0 °C. The resulting mixture was stirred for 2 h at room temperature, then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 20-65% MeCN/0.1% aqueous formic acid; detector, 220 nm; to afford 7-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-methyli midazo[1,5-a]pyridine-3- carboxamide (100 mg, 60% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 508 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.47 (s, 1H), 9.43 (dd, J = 7.5, 1.1 Hz, 1H), 8.60 (d, J = 4.8 Hz, 1H), 8.49 (d, J = 2.6 Hz, 1H), 8.08 (d, J = 2.7 Hz, 1H), 7.83 (s, 1H), 7.69 (d, J = 0.9 Hz, 1H), 7.35 (td, J = 9.1, 6.0 Hz, 1H), 7.21 (t, J = 9.4 Hz, 1H), 6.91 (dd, J = 7.5, 1.6 Hz, 1H), 3.91 (s, 3H), 2.84 (d, J = 4.8 Hz, 3H). Example 46: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 31) Synthesis of 31-a: 2-(5-bromopyrazin-2-yl)-2-[(diphenylmethylidene)amino] acetonitrile [0403] Into a 1000 mL 3-necked round-bottom flask was placed DMSO (400 mL) and NaH (6.7 g, 168 mmol, 2 equiv, 60% in oil). This was followed by the addition of a solution of 2- [(diphenylmethylidene)amino]acetonitrile (22 g, 100 mmol, 1.2 equiv) in DMSO (20 mL) dropwise with stirring at 0 °C. After 20 mins, a solution of 2,5-dibromopyrazine (20 g, 84 mmol, 1 equiv) in DMSO (20 mL) was added dropwise at 0 °C. The resulting solution was stirred for 2 h at room temperature, then quenched by the addition of 400 mL of saturated NH ₄ Cl. The resulting solution was extracted with 2 x 400 mL of ethyl acetate and the combined organics washed with 3 x 400 ml of water. The organics were dried over anhydrous sodium sulfate and concentrated. The residue was applied to a silica gel column eluting with ethyl acetate/petroleum ether (1/10) to give 2-(5-bromopyrazin-2-yl)-2- [(diphenylmethylidene)amino] acetonitrile (32 g, 81% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 377 Synthesis of 31-b: 2-amino-2-(5-bromopyrazin-2-yl)acetonitrile [0404] Into a 250 mL round-bottom flask was placed 2-(5-bromopyrazin-2-yl)-2- [(diphenylmethylidene)amino]acetonitrile (13 g, 34 mmol, 1 equiv), THF (20 mL) and 6 M aqueous HCl (100 mL). The resulting solution was stirred for 5 h at 25 °C, then extracted with 2 x 100 mL of dichloromethane. The pH of the aqueous was adjusted to 8 with NH ₃ .H ₂ O and this was extracted with 3 x 100 mL of dichloromethane. The combined organics were dried over anhydrous sodium sulfate and concentrated to give 2-amino-2-(5-bromopyrazin-2- yl)acetonitrile (5.3 g, 72% yield) as a brown solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 213 Synthesis of 31-c: 6-bromoimidazo[1,5-a]pyrazine-1-carbonitrile [0405] Into a 50 mL round-bottom flask was placed 2-amino-2-(5-bromopyrazin-2- yl)acetonitrile (4.2 g, 20 mmol, 1 equiv) and triethyl orthoformate (10 mL). The resulting solution was stirred for 2 h at 100 °C in an oil bath then cooled and filtered. The solids were dried to give 6-bromoimidazo[1,5-a]pyrazine-1-carbonitrile (1.2 g, 27% yield) as a yellow/brown solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 223 Synthesis of 31-d: 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1-carbo nitrile [0406] Into a 50 mL round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 6-bromoimidazo[1,5-a]pyrazine-1-carbonitrile (930 mg, 4 mmol, 1 equiv), 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)aniline (2.1 g, 8 mmol, 2 equiv), Sphos (342 mg, 0.8 mmol, 0.2 equiv), Sphos Pd Gen.3 (325 mg, 0.4 mmol, 0.1 equiv), dioxane (20 mL), H ₂ O (4 mL) and K ₂ CO ₃ (1.7 g, 12 mmol, 3 equiv). The resulting solution was stirred for 2 h at 80 °C in an oil bath, then cooled and filtered. The filtrate was diluted with water (10 ml) and extracted with DCM (3 x 10 ml). The combined organics were dried over anhydrous sodium sulfate and concentrated.6-(3-Amino-2,6- difluorophenyl)imidazo[1,5-a]pyrazine-1-carbonitrile (800 mg, 70% yield) was obtained as a brown solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 272 Synthesis of 31-e: 2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]aniline [0407] Into a 50 mL round-bottom flask was placed 6-(3-amino-2,6- difluorophenyl)imidazo[1,5-a]pyrazine-1-carbonitrile (680 mg, 2.5 mmol, 1 equiv), MeOH (25 mL) and MeONa (451 mg, 2.5 mmol, 1 equiv, 30% in MeOH). The resulting solution was stirred for 3 h at 50 °C, then cooled to room temperature. 2,2-Dimethoxyethanamine (395 mg, 3.7 mmol, 1.5 equiv) and AcOH (301 mg, 2 mmol, 2 equiv) were added sequentially, and the resulting solution stirred for 1 h at 50 °C. After cooling to room temperature, HCl (6 M) (2 mL) and MeOH (5 mL) were added. The resulting solution was stirred for 5 h at 100 °C, then concentrated. The residue was suspended in water (20 ml), and the pH adjusted to 8 with 30% aqueous NaOH. The solid formed was collected by filtration and dried to give 2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]aniline (660 mg, 84% yield) as a yellow solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 313 Synthesis of 31-f: 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imida zol-2- yl)imidazo[1,5-a]pyrazin-6-yl]aniline [0408] Into a 50 mL 3-necked round-bottom flask was placed 2,4-difluoro-3-[1-(1H- imidazol-2-yl)imidazo[1,5-a]pyrazin-6-yl]aniline (660 mg, 2 mmol, 1 equiv) and DMF (20 mL). NaH (127 mg, 3 mmol, 1.5 equiv, 60% in oil) was added in portions at 0 °C. To this was added SEM-Cl (528 mg, 3 mmol, 1.5 equiv) dropwise with stirring at 0 °C and the mixture was stirred in an ice bath for 3 h. The reaction was quenched by the addition of 30 mL of water, and extracted with 3 x 30 mL of ethyl acetate. The combined organics were washed with water (30 ml) and dried over anhydrous sodium sulfate, before being concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1/2), to give 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]aniline (400 mg, 43% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 443 Synthesis of 31-g: 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0409] Into an 8 mL vial, was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]aniline (200 mg, 0.4 mmol, 1 equiv), DCM (4 mL), pyridine (357 mg, 4.5 mmol, 10 equiv) and 5-chloro-2- methoxypyridine-3-sulfonyl chloride (164 mg, 0.6 mmol, 1.5 equiv). The resulting solution was stirred for 1 h at 25 °C, then concentrated. The crude product was purified by Flash- Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820- 40 μm, 120 g; mobile phase: 5-60% MeCN/ 0.1% aqueous formic acid; Detector, 220 nm.5- Chloro-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]me thyl]imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (130 mg, 44% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 648 Synthesis of Compound 31: 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0410] Into a 50 mL round-bottom flask was placed 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (160 mg, 0.2 mmol, 1 equiv), DCM (6 mL) and TFA (2 mL). The resulting solution was stirred for 1 h at 25 °C, then concentrated. The residue was purified by HPLC using the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 35-70% MeCN/0.1% aqueous formic acid; Detector, 220 nm. 5-Chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (70 mg 62% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 518 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.72 (s, 1H), 10.44 (s, 1H), 9.55 (d, J = 1.6 Hz, 1H), 8.66 (s, 1H), 8.56 (s, 1H), 8.49 (d, J = 2.6 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.40 (td, J = 8.8, 5.8 Hz, 1H), 7.22 (t, J = 9.0 Hz, 1H), 7.18 (s, 2H), 3.92 (s, 3H). Example 47: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(2H-pyrazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 32) Synthesis of 32-a: 2,4-difluoro-3-[1-[2-(oxan-2-yl)pyrazol-3-yl]imidazo[1,5-a]p yridin-6- yl]aniline [0411] To a stirred solution of 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyridin-6-yl]aniline (100 mg, 0.27 mmol, 1 equiv) and 1-(oxan-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)pyrazole (150 mg, 0.539 mmol, 2 equiv) in dioxane (5 mL) and H ₂ O (1 mL) were added Pd(dppf)Cl ₂ (20 mg, 0.027 mmol, 0.1 equiv) and K ₂ CO ₃ (75 mg, 0.539 mmol, 2 equiv) under N ₂ atmosphere. The reaction was then stirred at 80 °C for 5 h. The reaction was cooled to room temperature and H ₂ O (3 mL) was added. The mixture was extracted with EA (3 x 5 mL), and the combined organic layers were washed with brine (2 x 5 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford 2,4-difluoro-3-[1-[2- (oxan-2-yl)pyrazol-3-yl]imidazo[1,5-a]pyridin-6-yl]aniline (90 mg, 84% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 396 Synthesis of 32-b: 5-chloro-N-(2,4-difluoro-3-[1-[2-(oxan-2-yl)pyrazol-3-yl]imi dazo[1,5- a]pyridin-6-yl]phenyl)-2-methoxypyridine-3-sulfonamide [0412] A solution of 2,4-difluoro-3-[1-[2-(oxan-2-yl)pyrazol-3-yl]imidazo[1,5-a]p yridin-6- yl]aniline (90 mg, 0.228 mmol, 1 equiv) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (166 mg, 0.683 mmol, 3 equiv) in pyridine (4 mL) was stirred for 2 h at room temperature. The resulting mixture was concentrated under reduced pressure to give 5-chloro-N-(2,4- difluoro-3-[1-[2-(oxan-2-yl)pyrazol-3-yl]imidazo[1,5-a]pyrid in-6-yl]phenyl)-2- methoxypyridine-3-sulfonamide (60 mg, crude) as a yellow oil which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 601 Synthesis of Compound 32: 5-chloro-N-[2,4-difluoro-3-[1-(2H-pyrazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0413] A solution of 5-chloro-N-(2,4-difluoro-3-[1-[2-(oxan-2-yl)pyrazol-3-yl]imi dazo[1,5- a]pyridin-6-yl]phenyl)-2-methoxypyridine-3-sulfonamide (60 mg, 0.1 mmol, 1 equiv) in TFA (1 mL) and DCM (3 mL) was stirred for 1 h at room temperature. The reaction mixture was concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 30-80% MeCN/0.1% aqueous formic acid; Detector, 220 nm; to afford 5-chloro-N-[2,4- difluoro-3-[1-(2H-pyrazol-3-yl)imidazo[1,5-a]pyridin-6-yl]ph enyl]-2-methoxypyridine-3- sulfonamide (18 mg, 35% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 517 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.81 (s, 1H), 10.47 (s,1H), 8.53 – 8.42 (m, 3H), 8.11 (s, 1H), 8.08 (d, J = 2.6 Hz, 1H), 7.74 (s, 1H), 7.36 (td, J = 8.8, 5.9 Hz, 1H), 7.28-7.16 (m, 1H), 6.78 (d, J = 9.4 Hz, 1H), 6.67 (d, J = 2.2 Hz, 1H), 3.92 (s, 3H).

Example 48: Synthesis of (6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,7-dimethyl-5H,6H,8H-imidazo[1,5-a]pyrazine -1-carboxamide and (6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N,7- dimethyl-5H,6H,8H-imidazo[1,5-a]pyrazine-1-carboxamide (Compounds 33-1 & 33-2) Synthesis of 33-a: ethyl 6-(3-amino-2,6-difluorophenyl)-5H,6H,7H,8H-imidazo[1,5- a]pyrazine-1- carboxylate [0414] Into a 50 mL pressure tank reactor purged and maintained with an inert atmosphere of nitrogen, was placed ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1- carboxylate (500 mg), 10% Pd/C (500 mg), MeOH (10 mL) and HCl (1 mL, 12 M). The reactor was charged with H ₂ (g) at 20 atm and the reaction stirred for 1 h at 80 °C in an oil bath. The reaction mixture was cooled to room temperature and filtered. The filtrate was concentrated, and the residue purified by prep-HPLC with the following conditions: Column, WelFlash TMC18-I, Spherical C1820-40 um, 120 g; mobile phase: 20-75% MeCN/0.1% aqueous formic acid; Detector, 220 nm. Ethyl 6-(3-amino-2,6-difluorophenyl)-5H,6H,7H,8H- imidazo[1,5-a]pyrazine-1-carboxylate (400 mg ) was isolated as a white solid. LCMS (ES, m/z): [M+H]+: 323 Synthesis of 33-b: ethyl 6-(3-amino-2,6-difluorophenyl)-7-methyl-5H,6H,8H-imidazo[1,5 - a]pyrazine-1- carboxylate [0415] Into a 50 mL 3-necked round-bottom flask was placed ethyl 6-(3-amino-2,6- difluorophenyl)-5H,6H,7H,8H-imidazo[1,5-a]pyrazine-1-carboxy late (400 mg, 1.2 mmol, 1 equiv), MeOH (10 mL) and HCHO (1.07 g, 12.4 mmol, 10 equiv, 37% in water). This was followed by the addition of NaBH(AcO) ₃ (526 mg, 2.5 mmol, 2 equiv) in portions at room temperature. The resulting solution was stirred overnight, then filtered. The filtrate was concentrated and the residue purified by Prep-HPLC with the following conditions: Column, WelFlash TMC18-I, Spherical C1820-40 um, 120 g; mobile phase: 15-75% MeCN / 0.1% aqueous formic acid; Detector, 220 nm. Ethyl 6-(3-amino-2,6-difluorophenyl)-7-methyl- 5H,6H,8H-imidazo[1,5-a]pyrazine-1-carboxylate (300 mg, 72% yield) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 337 Synthesis of 33-c: 6-(3-amino-2,6-difluorophenyl)-N,7-dimethyl-5H,6H,8H-imidazo [1,5- a]pyrazine-1- carboxamide [0416] Into a 50 mL 3-necked round-bottom flask was placed ethyl 6-(3-amino-2,6- difluorophenyl)-7-methyl-5H,6H,8H-imidazo[1,5-a]pyrazine-1-c arboxylate (300 mg, 0.9 mmol, 1 equiv). This was followed by the addition of 2 M methylamine in methanol (5 mL) dropwise with stirring at room temperature. The resulting solution was stirred for 24 h at room temperature, then concentrated. The reaction mixture was purified by Prep-HPLC with the following conditions: Column, WelFlash TMC18-I, Spherical C1820-40 um, 120 g; mobile phase: 25-95% MeCN / 0.1% aqueous formic acid; Detector, 220 nm.6-(3-Amino- 2,6-difluorophenyl)-N,7-dimethyl-5H,6H,8H-imidazo[1,5-a]pyra zine-1-carboxamide (200 mg, 70% yield) was obtained as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 322 Synthesis of Compound 33-1 & 33-2: (6R)-6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N,7-dimethyl-5H,6H,8H-imida zo[1,5-a]pyrazine-1- carboxamide and (6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,7-dimethyl-5H,6H,8H-imidazo[1,5-a]pyrazine -1-carboxamide [0417] Into an 8 mL vial was placed 6-(3-amino-2,6-difluorophenyl)-N,7-dimethyl- 5H,6H,8H-imidazo[1,5-a]pyrazine-1-carboxamide (150 mg, 0.5 mmol, 1 equiv), DCM (3.00 mL), pyridine (369 mg, 4.7 mmol, 10 equiv) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (135 mg, 0.5 mmol, 1.2 equiv). The resulting solution was stirred for 3 h at rt, then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TMC18-I, Spherical C1820-40 um, 120 g; mobile phase: 5- 60% MeCN / 0.1% aqueous formic acid; Detector, 220 nm. The enantiomers were separated by Chiral-Prep-HPLC with the following conditions: Column, CHIRALPAK IC 250*20 mm; mobile phase, Hexane + 0.1%DEA and 50% EtOH; Detector, 254 nm. This gave (6R)-6-[3- (5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoropheny l]-N,7-dimethyl-5H,6H,8H- imidazo[1,5-a]pyrazine-1-carboxamide (15 mg 6% yield) as a white solid and (6S)-6-[3-(5- chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]- N,7-dimethyl-5H,6H,8H- imidazo[1,5-a]pyrazine-1-carboxamide (16 mg, 6.5% yield) as a white solid. Stereochemistry was randomly assigned. LCMS (ES, m/z): [M+H] ⁺ : 527 for both isomers (6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N,7-dimethyl- 5H,6H,8H-imidazo[1,5-a]pyrazine-1-carboxamide: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.36 (s, 1H), 8.50 (d, J = 2.6 Hz, 1H), 7.96 (d, J = 2.6 Hz, 1H), 7.80 (d, J = 4.9 Hz, 1H), 7.59 (s, 1H), 7.42-7.34 (m, 1H), 7.15 (t, J = 9.4 Hz, 1H), 4.29 (dd, J = 10.9, 3.1 Hz, 1H), 4.20 (d, J = 16.3 Hz, 1H), 4.17-4.00 (m, 2H), 3.94 (s, 3H), 3.55 (d, J = 16.3 Hz, 1H), 2.72 (d, J = 4.7 Hz, 3H), 1.98 (s, 3H). (6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N,7-dimethyl- 5H,6H,8H-imidazo[1,5-a]pyrazine-1-carboxamide: ¹ H NMR-0B (300 MHz, DMSO-d ₆ ) δ 10.36 (s, 1H), 8.50 (d, J = 2.6 Hz, 1H), 7.96 (d, J = 2.6 Hz, 1H), 7.80 (d, J = 4.9 Hz, 1H), 7.59 (s, 1H), 7.42-7.34 (m, 1H), 7.14 (t, J = 9.5 Hz, 1H), 4.29 (dd, J = 11.0, 3.2 Hz, 1H), 4.20 (d, J = 16.3 Hz, 1H), 4.18-4.00 (m, 2H), 3.94 (s, 3H), 3.55 (d, J = 16.4 Hz, 1H), 2.72 (d, J = 4.7 Hz, 3H), 1.98 (s, 3H).

Example 49: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(3H-1,2,3-triazol-4- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]- 2-methoxypyridine-3-sulfonamide (Compound 34) Compound 34 Synthesis of 34-a: 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine-1-carbo xylic acid [0418] To a stirred solution of ethyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine- 1-carboxylate (2.1 g, 6.6 mmol, 1 equiv) in a mixture solution of THF (8 mL), MeOH (8 mL) and H ₂ O (4 mL) was added LiOH (0.5 g, 20 mmol, 3 equiv) and the reaction was stirred at room temperature for 1 h. The resulting solution was concentrated under vacuum to remove THF and MeOH, and the residue was diluted with H ₂ O (10 mL) and then acidified to pH 2 with 2 M HCl (10 mL). The precipitated solids were collected by filtration and washed with H ₂ O (10 mL). The filter cake was dried under vacuum to give 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine- 1-carboxylic acid (1.8 g, 94% yield) as a brown solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 290 Synthesis of 34-b: 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyridin-6-yl]aniline [0419] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine-1- carboxylic acid (1.8 g, 6 mmol, 1 equiv) in DMF (20 mL) was added NaHCO ₃ (2.1 g, 24 mmol, 4 equiv) and NIS (1.4 g, 6 mmol, 1 equiv) and the reaction stirred at room temperature overnight. The mixture was diluted with H ₂ O (40 mL) and extracted with EA (50 mL x 3). The combined organics were dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure, and the residue purified by silica gel column chromatography, eluting with PE:EA (2:1) to give 2,4-difluoro-3-[1- iodoimidazo[1,5-a]pyridin-6-yl]aniline (1.4 g, 60% yield) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 372 Synthesis of 34-cA 34-cB: 2-(oxan-2-yl)-1,2,3-triazole and 1-(oxan-2-yl)-1,2,3-triazole [0420] To a stirred solution of 1,2,3- triazole (1 g, 14.5 mmol, 1 equiv) in DCM (48 mL) was added DHP (2.4 g, 29 mmol, 2 equiv) and TsOH (25 mg, 0.145 mmol, 0.01 equiv), and the reaction was stirred at room temperature overnight. H ₂ O (10 mL) was added the mixture extracted with DCM (30 mL x 3). The combined organics were dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE (5 min) and then EA (10 min) to afford a mixture of 2-(oxan-2-yl)-1,2,3-triazole and 1-(oxan-2-yl)-1,2,3- triazole (2 g, 90% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 154 Synthesis of 34-dA & 34-dB: 2-(oxan-2-yl)-4-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)- 1,2,3-triazole and 1-(oxan-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl ) -1,2,3- triazole [0421] To a stirred solution of [Ir(COD)OMe] ₂ (26 mg, 0.04 mmol, 0.03 equiv) and dtbbpy (21 mg, 0.08 mmol, 0.06 equiv) in hexane (3.3 mL) was added bis(pinacolato)diboron (365 mg, 1.4 mmol, 1.1 equiv) at room temperature under N ₂ atmosphere, and the reaction was stirred at room temperature for 15 min. The mixture of 1-(oxan-2-yl)-1,2,3-triazole) and 2- (oxan-2-yl)-1,2,3-triazole (200 mg, 1.3 mmol, 1 equiv) was added, and the reaction stirred at room temperature overnight. The resulting mixture was filtered and the filter cake was washed with hexane (10 mL). The filtrate was concentrated under reduced pressure to give the mixture of 2-(oxan-2-yl)-4-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)-1,2,3-triazole and 1-(oxan-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl )-1,2,3-triazole (400 mg, crude) as a red oil. LCMS (ES, m/z): [M+H] ⁺ : 280 Synthesis of 34-eA & 34-eB: 2,4-difluoro-3-[1-[2-(oxan-2-yl) -1,2,3-triazol-4- yl]imidazo[1,5-a]pyridin-6-yl]aniline and 2,4-difluoro-3-[1-[3-(oxan-2-yl)-4,5-dihydro-1,2,3- triazol-4 -yl]imidazo[1,5-a]pyridin-6-yl]aniline [0422] To a stirred solution of 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyridin-6- yl]aniline (170 mg, 0.46 mmol, 1 equiv) in dioxane (1.5 mL) and H ₂ O (0.3 mL) was added mixture of 1-(oxan-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2- yl)-1,2,3-triazole) and 2-(oxan-2-yl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl )-1,2,3- triazole (257 mg, 0.92 mmol, 2 equiv). Pd(dppf)Cl ₂ (32 mg, 0.046 mmol, 0.1 equiv) and K ₂ CO ₃ (127 mg, 0.92 mmol, 2 equiv) were added, and the resulting solution was degassed with N ₂ , then stirred at 80 °C for 3 h. The reaction was cooled to room temperature and diluted with H ₂ O (5 mL), before being extracted with EA (5 mL x 3). The combined organics were dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:4) to afford a mixture of 2,4-difluoro-3-[1-[2-(oxan-2-yl)-1,2,3-triazol-4-yl]imidazo[ 1,5-a]pyridin-6- yl]aniline and 2,4-difluoro-3-[1-[3-(oxan-2-yl)-4,5-dihydro-1,2,3-triazol-4 -yl]imidazo[1,5- a]pyridin-6-yl]aniline (100 mg, 55% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 397 Synthesis of 34-fA & 34-fB: 5-chloro-N-(2,4-difluoro-3-[1-[2-(oxan-2-yl)-1,2,3- triazol-4- yl]imidazo[1,5-a]pyridin- 6-yl]phenyl)-2-methoxypyridine-3-sulfonamide [0423] To a stirred solution of a mixture of 2,4-difluoro-3-[1-[3-(oxan-2-yl)-4,5-dihydro- 1,2,3-triazol-4-yl]imidazo[1,5-a] pyridine-6-yl]aniline) and 2,4-difluoro-3-[1-[2-(oxan-2-yl)- 1,2,3-triazol-4-yl]imidazo[1,5-a]pyridin-6-yl]aniline (100 mg, 0.25 mmol, 1 equiv) in DCM (5 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (61 mg, 0.25 mmol, 1 equiv) and pyridine (60 mg, 0.75 mmol, 3 equiv). The reaction was stirred at room temperature overnight then concentrated. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford a mixture of 5-chloro-N-(2,4-difluoro-3- [1-[3-(oxan-2-yl)-1,2,3-triazol-4-yl]imidazo[1,5-a]pyridine- 6-yl]phenyl)-2-methoxypyridine- 3-sulfonamide and 5-chloro-N-(2,4-difluoro-3-[1-[2-(oxan-2-yl)-1,2,3-triazol-4 - yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-2-methoxypyridine-3-su lfonamide (70 mg, 46% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 602 Synthesis of Compound 34: 5-chloro-N-[2,4-difluoro-3-[1-(3H-1,2,3-triazol-4- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]- 2-methoxypyridine-3-sulfonamide [0424] A mixture of 5-chloro-N-(2,4-difluoro-3-[1-[3-(oxan-2-yl)-1,2,3-triazol-4 - yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-2- methoxypyridine-3-sulfonamide) and 5-chloro-N- (2,4-difluoro-3-[1-[2-(oxan-2-yl)-1,2,3-triazol-4-yl]imidazo [1,5-a]pyridin-6-yl]phenyl)-2- methoxypyridine-3-sulfonamide (70 mg) in 6 M HCl in MeOH (5 mL) was stirred at room temperature for 2 hours. The solution was concentrated directly and the residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 25-65% MeCN/0.1% aqueous formic acid; Detector, 220 nm; to give 5-chloro-N-[2,4-difluoro-3-[1-(3H-1,2,3-triazol-4-yl)imidazo [1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide (27 mg, 45% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 518. ¹ H NMR (300 MHz, Methanol-d4) δ 8.47 (s, 1H), 8.38 (s, 1H), 8.37 (d, J = 2.6 Hz, 1H), 8.17 (s, 2H), 8.10 (d, J = 2.6 Hz, 1H), 7.58-7.50 (m, 1H), 7.13 (td, J = 9.2, 1.8 Hz, 1H), 6.90 (d, J = 9.8 Hz, 1H), 4.04 (s, 3H). Example 50: Synthesis of 5-chloro-N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 35) Compound 35 Synthesis of 35-a: 1H-imidazole-2-carbonyl chloride [0425] To a stirred solution of 1H-imidazole-2-carboxylic acid (8 g, 71 mmol, 1 equiv) and DMF (2 drops) in DCM (60 mL) were added oxalyl chloride (18 g, 143 mmol, 2 equiv) dropwise at 0 °C. The resulting solution was stirred at room temperature for 3 h, then concentrated under reduced pressure to afford 1H-imidazole-2-carbonyl chloride (8 g, crude) as a yellow solid which was used in the next step directly without further purification. Synthesis of 35-b: N-[(4-chloropyridin-2-yl)methyl]-1H-imidazole-2-carboxamide [0426] To a stirred solution of 1-(4-chloropyridin-2-yl)methanamine (6 g, 42 mmol, 1 equiv) and TEA (12 g, 126 mmol, 3 equiv) in DCM (100 mL) were added a solution of 1H- imidazole-2-carbonyl chloride (6 g, 50 mmol, 1.2 equiv) in DCM (20 mL) at 0 °C. The resulting solution was stirred at room temperature for 1 h. The reaction mixture was concentrated under reduced pressure to give a residue, which was purified by column chromatography over silica gel (eluent: PE:EA = 1:1) to afford N-[(4-chloropyridin-2- yl)methyl]-1H-imidazole-2-carboxamide (6 g, 60% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 237 Synthesis of 35-c: 2-[7-chloroimidazo[1,5-a]pyridin-3-yl]-1H-imidazole [0427] A mixture of N-[(4-chloropyridin-2-yl)methyl]-1H-imidazole-2-carboxamide (4 g, 17 mmol, 1 equiv) in POCl ₃ (50 mL) was stirred for 2 h at 110 °C. The mixture was allowed to cool to room temperature, then was concentrated and the residue quenched by careful addition of saturated aqueous NaHCO ₃ (100 mL). The resulting mixture was extracted with EA (3 x 200 mL). The combined organics were washed with brine (3 x 100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:5) to afford 2-[7- chloroimidazo[1,5-a]pyridin-3-yl]-1H-imidazole (1.7 g, 46% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 219 Synthesis of 35-d: 2-[7-chloroimidazo[1,5-a]pyridin-3-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole [0428] To a stirred solution of 2-[7-chloroimidazo[1,5-a]pyridin-3-yl]-1H-imidazole (1.7 g, 7.7 mmol, 1 equiv) in THF (50 mL) was added NaH (621 mg, 15.5 mmol, 2 equiv, 60% in oil) portion wise at 0 °C under nitrogen atmosphere. The reaction mixture was stirred for 0.5 h at 0 °C, then SEM-Cl (1.94 g, 11.663 mmol, 1.5 equiv) was added and the mixture stirred for 1 h at 0 °C. The resulting mixture was quenched with water (100 mL) and extracted with EA (3 x 100 mL). The combined organics were washed with brine (3 x 100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford 2-[7- chloroimidazo[1,5-a]pyridin-3-yl]-1-[[2-(trimethylsilyl)etho xy]methyl]imidazole (1.5 g, 55% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 349 Synthesis of 35-e: 2,4-difluoro-3-[3-(1-[[2-(trimethylsilyl)ethoxy]methyl]imida zol-2- yl)imidazo[1,5-a]pyridin-7-yl]aniline [0429] To a stirred solution of 2-[7-chloroimidazo[1,5-a]pyridin-3-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (1.5 g, 4.3 mmol, 1 equiv), 2,4-difluoro-3-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (2.19 g, 9 mmol, 2 equiv) K ₂ CO ₃ (1.19 g, 9 mmol, 2 equiv) in dioxane (20 mL) and H ₂ O (4 mL) were added XPhos (204 mg, 0.4 mmol, 0.1 equiv) and XPhos Pd G3 (363 mg, 0.4 mmol, 0.1 equiv) at room temperature under nitrogen atmosphere. The reaction mixture was stirred for 3 h at 100 °C then cooled. The resulting mixture was diluted with water (100 mL) and extracted with EA (3 x 50 mL). The combined organics were washed with brine (3 x 20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (5:1) to afford 2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]aniline (1.3 g, 68% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 442 Synthesis of 35-f: 5-chloro-N-[2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0430] To a stirred solution of 2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]aniline (100 mg, 0.2 mmol, 1 equiv) and pyridine (53 mg, 0.6 mmol, 3 equiv) in DCM (5 mL) was added 5- chloro-2-methoxypyridine-3-sulfonyl chloride (82 mg, 0.3 mmol, 1.5 equiv) in portions at room temperature. The resulting mixture was stirred for 1 h then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (4:1) to afford 5-chloro-N-[2,4-difluoro-3-[3-(1-[[2-(trimethylsilyl)ethoxy] methyl]imidazol- 2-yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-2-methoxypyridine-3- sulfonamide (145 mg, 98% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 647 Synthesis of Compound 35: 5-chloro-N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0431] To a stirred solution of 5-chloro-N-[2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide (150 mg, 0.2 mmol, 1 equiv) in DCM (4 mL) was added TFA (1 mL) dropwise at room temperature. The resulting mixture was stirred for 2 h then concentrated under vacuum. The residue was purified by prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 36-49% MeCN/0.1% aqueous ammonia; Detector, 220 nm; to afford 5-chloro-N-[2,4-difluoro-3-[3- (1H-imidazol-2-yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-2-metho xypyridine-3-sulfonamide (26 mg, 22% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 517 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.96 (s, 1H), 10.46 (s, 1H), 9.57 (d, J = 7.5 Hz, 1H), 8.48 (d, J = 2.6 Hz, 1H), 8.07 (d, J = 2.6 Hz, 1H), 7.76 (s, 1H), 7.68 (s, 1H), 7.39-7.25 (m, 2H), 7.20 (d, J = 11.5 Hz, 2H), 6.83 (d, J = 7.5 Hz, 1H), 3.91 (s, 3H). Example 51: Synthesis of N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin - 7-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (Compound 36) Compound 36 Synthesis of 36-a: N-[2,4-difluoro-3-[3-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide [0432] To a stirred solution of 2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]aniline (150 mg, 0.3 mmol, 1 equiv) and pyridine (80 mg, 1 mmol, 3 equiv) in DCM (5 mL) was added 5-fluoro- 2-methoxypyridine-3-sulfonyl chloride (114 mg, 0.5 mmol, 1.5 equiv) in portions at room temperature. The resulting mixture was stirred for 1 h, then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (4:1) to afford N-[2,4-difluoro-3-[3-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide (160 mg, 74% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 631 Synthesis of Compound 36: N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin -7- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide [0433] To a stirred solution of N-[2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (100 mg, 0.1 mmol, 1 equiv) in DCM (4 mL) was added TFA (1 mL) dropwise at room temperature. The resulting mixture was stirred for 2 h, then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 32-44% MeCN / 0.1% aqueous ammonia; Detector, 220 nm; to afford N-[2,4-difluoro-3-[3-(1H- imidazol-2-yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-5-fluoro-2- methoxypyridine-3- sulfonamide (36 mg, 45% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 501 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.96 (s, 1H), 10.40 (s, 1H), 9.57 (d, J = 7.5 Hz, 1H), 8.45 (d, J = 3.0 Hz, 1H), 8.01 (dd, J = 7.3, 3.0 Hz, 1H), 7.76 (s, 1H), 7.68 (d, J = 0.9 Hz, 1H), 7.39-7.28 (m, 2H), 7.20 (d, J = 14.0 Hz, 2H), 6.82 (d, J = 7.5 Hz, 1H), 3.91 (s, 3H).

Example 52: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 37) Compound 37 Synthesis of 37-a: 2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5-a]pyridi n-6- yl]aniline [0434] Into a 50 mL round-bottom flask was placed 2,4-difluoro-3-[1-iodoimidazo[1,5- a]pyridin-6-yl]aniline (200 mg, 0.5 mmol, 1 equiv), 1-methyl-3-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)pyrazole (168 mg, 0.8 mmol, 1.5 equiv), K ₂ CO ₃ (223 mg, 1.6 mmol, 3 equiv), dioxane (8 mL) and H ₂ O (2 mL, 0.1 mmol). Pd(dppf)Cl ₂ (39 mg, 0.05 mmol, 0.1 equiv) was added in portions at room temperature under N ₂ atmosphere. The resulting solution was stirred for 2 h at 85 °C in an oil bath, then cooled and concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE:EA (4:1) to afford 2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5-a]pyridi n-6-yl]aniline (150 mg, 86% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 326 Synthesis of Compound 37: 5-chloro-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0435] Into a 25 mL round-bottom flask was placed 2,4-difluoro-3-[1-(1-methylpyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]aniline (130 mg, 0.4 mmol, 1 equiv), pyridine (4 mL), 5- chloro-2-methoxypyridine-3-sulfonyl chloride (145 mg, 0.6 mmol, 1.5 equiv) and DCM (1 mL). The resulting solution was stirred for 1 h at room temperature, then concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 35-75% MeCN / 0.1% aqueous formic acid; to afford 5-chloro-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (80 mg, 38% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 531 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.54-8.42 (m, 3H), 8.17-8.05 (m, 2H), 7.73 (d, J = 2.2 Hz, 1H), 7.36 (td, J = 8.9, 5.9 Hz, 1H), 7.23 (td, J = 9.2, 1.6 Hz, 1H), 6.76 (dt, J = 9.4, 1.5 Hz, 1H), 6.62 (d, J = 2.2 Hz, 1H), 3.91 (s, 3H), 3.92 (s, 3H).

Example 53: Synthesis of 5-chloro-N-[2-cyano-4-fluoro-3-[1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 38) Compound 38 Synthesis of 38-a: 2-bromo-3-fluoro-6-nitrobenzoic acid [0436] Into a 100 mL 3-necked round-bottom flask was placed 2-bromo-3-fluorobenzoic acid (5 g, 23 mmol, 1 equiv) and H ₂ SO ₄ (30 mL), followed by the addition of HNO ₃ (3 mL) dropwise with stirring at 0 °C. The resulting solution was stirred for 60 min at 0 °C in an ice/salt bath. The reaction was then quenched by the addition of 100 mL of water/ice, and the resulting solution extracted with 2 x 70 mL of ethyl acetate. The combined organics were washed with 100 ml of brine, dried over anhydrous sodium sulfate and concentrated under vacuum.2-Bromo-3-fluoro-6-nitrobenzoic acid (3 g) was isolated as crude yellow solid which was used in next step directly without further purification. Synthesis of 38-b: 2-bromo-3-fluoro-6-nitrobenzoyl chloride [0437] Into a 250 mL 3-necked round-bottom flask was placed 2-bromo-3-fluoro-6- nitrobenzoic acid (3 g, 11 mmol, 1 equiv) in DCM (100 mL). This was followed by the addition of SOCl ₂ (2.7 g, 23 mmol, 2 equiv) dropwise with stirring at room temperature. The resulting solution was stirred for 60 min at room temperature, then concentrated under vacuum. This gave 2-bromo-3-fluoro-6-nitrobenzoyl chloride (3 g) as a yellow oil which was used in next step directly without further purification. Synthesis of 38-c: 2-bromo-3-fluoro-6-nitrobenzamide [0438] Into a 250 mL 3-necked round-bottom flask was placed 2-bromo-3-fluoro-6- nitrobenzoyl chloride (3 g, 11 mmol, 1 equiv) in THF (80 mL). This solution was saturated with ammonia gas at room temperature, then stirred for 30 min. The resulting mixture was concentrated under vacuum to give 2-bromo-3-fluoro-6-nitrobenzamide (3.5 g) as a white solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 263 Synthesis of 38-d: 6-amino-2-bromo-3-fluorobenzamide [0439] Into a 25 mL 3-necked round-bottom flask was placed 2-bromo-3-fluoro-6- nitrobenzamide (1.5 g, 5.7 mmol, 1 equiv), AcOH (20 mL) and iron powder (955 mg, 17 mmol, 3 equiv). The resulting solution was stirred for 2 hr at 90 °C in an oil bath. The solids were removed by filtration and the filtrate concentrated under vacuum. The residue was diluted with 50 mL of H ₂ O, and the pH adjusted to 10 with ammonia solution. The resulting mixture was extracted with 3 x 50 mL of dichloromethane and the organic layers combined and dried over anhydrous sodium sulfate. Concentration yielded 6-amino-2-bromo-3- fluorobenzamide (900 mg) as a brown oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ :233 Synthesis of 38-e: 2-bromo-6-(5-chloro-2-methoxypyridine-3-sulfonamido)-3- fluorobenzamide [0440] Into a 25 mL 3-necked round-bottom flask was placed 6-amino-2-bromo-3- fluorobenzamide (800 mg, 3.4 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (831 mg, 3.4 mmol, 1 equiv) and pyridine (5 mL). The resulting solution was stirred for 60 min at 50 °C in an oil bath. The reaction was quenched by the addition of 50 mL of water and the resulting solution extracted with 4 x 50 mL of dichloromethane. The combined organics were dried over anhydrous sodium sulfate and concentrated to give 2-bromo-6-(5- chloro-2-methoxypyridine-3-sulfonamido)-3-fluorobenzamide (700 mg) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ :438 Synthesis of 38-f: N-(3-bromo-2-cyano-4-fluorophenyl)-5-chloro-2-methoxypyridin e-3- sulfonamide [0441] Into a 100 mL 3-necked round-bottom flask was placed 2-bromo-6-(5-chloro-2- methoxypyridine-3-sulfonamido)-3-fluorobenzamide (600 mg, 1.4 mmol, 1 equiv), THF (20 mL) and TEA (415 mg, 4.1 mmol, 3 equiv). TFAA (862 mg, 4 mmol, 3 equiv) was added dropwise and the resulting solution was stirred for 30 min at room temperature, before being concentrated under vacuum. The crude product was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm ; Mobile Phase 50-80% MeCN/0.1% aqueous formic acid; Detector, 220 nm. N-(3-Bromo-2-cyano-4- fluorophenyl)-5-chloro-2-methoxypyridine-3-sulfonamide (240 mg, 40% yield) was obtained as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 420 Synthesis of 38-g: 5-chloro-N-[2-cyano-4-fluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0442] Into a 25 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen was placed N-(3-bromo-2-cyano-4-fluorophenyl)-5-chloro-2- methoxypyridine-3-sulfonamide (100 mg, 0.24 mmol, 1 equiv), 2-[6-(4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl)imidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (105 mg, 0.24 mmol, 1 equiv), Pd(dppf)Cl ₂ (18 mg, 0.024 mmol, 0.1 equiv), K ₂ CO ₃ (99 mg, 0.7 mmol, 3 equiv), dioxane (5 mL) and H ₂ O (1 mL). The resulting solution was stirred for 2 hr at 85 °C in an oil bath, then concentrated under vacuum. The residue was applied to a silica gel column, eluting with THF:PE (1:1) to give 5-chloro-N-[2-cyano-4-fluoro-3-[1-(1-[[2-(trimethylsilyl)eth oxy]methyl]imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (104 mg, 83% yield) as a yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ :654 Synthesis of Compound 38: 5-chloro-N-[2-cyano-4-fluoro-3-[1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0443] Into a 25 mL 3-necked round-bottom flask was placed 5-chloro-N-[2-cyano-4-fluoro- 3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imid azo[1,5-a]pyridin-6-yl]phenyl]- 2-methoxypyridine-3-sulfonamide (104 mg, 0.16 mmol, 1 equiv) and TFA (2 mL). The resulting solution was stirred for 60 min at 70 °C in an oil bath, then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 10-50% MeCN/0.1% aqueous formic acid; Detector, 220 nm. 5-Chloro-N-[2-cyano-4-fluoro-3-[1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (5.2 mg, 6% yield) was isolated as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 524 ¹ H NMR (300 MHz, Methanol-d ₄ ) δ 8.49 (d, J = 8.8 Hz, 2H), 8.32 (d, J = 2.6 Hz, 1H), 8.18 (d, J = 9.4 Hz, 1H), 8.12 (d, J = 2.6 Hz, 1H), 7.61 (dd, J = 9.1, 4.7 Hz, 1H), 7.51 (t, J = 9.1 Hz, 1H), 7.23 (s, 2H), 7.08-6.99 (m, 1H), 3.99 (s, 3H). Example 54: Synthesis of 6-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-1-hydroxy-2,3-dihydro-1H-indene-4-sul fonamide (Compound 39) C ^{ompound 39} Synthesis of 39-a: 6-cyano-4-([2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]sulfamoyl)- 2,3-dihydro-1H-inden-1-yl acetate [0444] Into a 25 mL 3-necked round-bottom flask was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (200 mg, 0.45 mmol, 1 equiv), pyridine (4 mL) and 4-(chlorosulfonyl)-6-cyano-2,3-dihydro-1H-inden- 1-yl acetate (136 mg, 0.45 mmol, 1 equiv). The resulting solution was stirred for 1h at 45 °C in an oil bath, then concentrated under vacuum. The residue was applied to a silica gel column, eluting with THF:PE (1:3).6-Cyano-4-([2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]sulfamoyl)- 2,3-dihydro-1H-inden-1-yl acetate (193 mg, 80% yield) was obtained as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 705 Synthesis of 39-b: 6-cyano-4-([2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6- yl]phenyl]sulfamoyl)-2,3-dihydro-1H-inden-1-yl acetate [0445] Into a 25 mL 3-necked round-bottom flask was placed 6-cyano-4-([2,4-difluoro-3-[1- (1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1 ,5-a]pyridin-6- yl]phenyl]sulfamoyl)-2,3-dihydro-1H-inden-1-yl acetate (193 mg, 0.3 mmol, 1 equiv) and TFA (2 mL). The resulting solution was stirred for 30 min at 70 °C in an oil bath, then concentrated under vacuum. The residue was diluted with 20 mL of DCM, and the pH value of the solution was adjusted to 7~8 with saturated NaHCO ₃ solution. The organics were dried over anhydrous sodium sulfate, and concentrated under vacuum to give 6-cyano-4-([2,4- difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]p henyl]sulfamoyl)-2,3-dihydro- 1H-inden-1-yl acetate (137 mg, 80% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 575 Synthesis of Compound 39: 6-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-1-hydroxy-2,3-dihydro-1H-indene-4-sul fonamide [0446] Into a 25 mL 3-necked round-bottom flask was placed 6-cyano-4-([2,4-difluoro-3-[1- (1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]sulfamoy l)-2,3-dihydro-1H-inden-1-yl acetate (137 mg, 0.24 mmol, 1 equiv) in MeOH (10 mL). NaOH (29 mg, 0.72 mmol, 3 equiv) in H ₂ O (2 mL) was added dropwise with stirring and the resulting solution was stirred for 30 min at room temperature. The pH was adjusted to 5~6 with 2 M HCl/H ₂ O and the resulting mixture concentrated under vacuum. The residue was diluted with 15 mL of H ₂ O and extracted with 3 x 15 mL of dichloromethane. The combined organics were dried over anhydrous sodium sulfate and concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile phase: 20-65% 1:1 ACN:MeOH / aqueous NH ₄ HCO ₃ (10 mmol); Detector, 220 nm. 6-Cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a ]pyridin- 6-yl]phenyl]-1-hydroxy-2,3-dihydro-1H-indene-4-sulfonamide (33.4 mg, 25% yield) was isolated as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 533 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.48 (d, J = 11.0 Hz, 2H), 8.21 (d, J = 9.4 Hz, 1H), 7.98- 7.90 (m, 2H), 7.28 (td, J = 8.9, 5.8 Hz, 1H), 7.15 (t, J = 9.3 Hz, 1H), 7.07 (s, 2H), 6.79 (d, J = 9.4 Hz, 1H), 5.64 (d, J = 5.7 Hz, 1H), 5.10 (q, J = 6.5 Hz, 1H), 3.21 (dd, J = 8.8, 3.7 Hz, 1H), 2.95 (dt, J = 17.5, 8.0 Hz, 1H), 2.38 (d, J = 13.1 Hz, 1H), 1.78 (dd, J = 13.1, 6.9 Hz, 1H). Example 55: Synthesis of 5-cyano-N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 40) Compound 40 Synthesis of 40-a: 5-cyano-N-[2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0447] To a solution of 2,4-difluoro-3-[3-(1-[[2-(trimethylsilyl)ethoxy]methyl]imida zol-2- yl)imidazo[1,5-a]pyridin-7-yl]aniline (100 mg, 0.2 mmol, 1 equiv) in DCM (5 mL) were added pyridine (53 mg, 0.6 mmol, 3 equiv) and 5-cyano-2-methoxypyridine-3-sulfonyl chloride (79 mg, 0.3 mmol, 1.5 equiv). The resulting solution was stirred at room temperature for 3 hours, then concentrated to give the 5-cyano-N-[2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide (120 mg, 83% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 638 Synthesis of Compound 40: 5-cyano-N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0448] To a stirred solution of 5-cyano-N-[2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide (60 mg, 1 equiv) in DCM (4 mL) was added TFA (1 mL) dropwise at room temperature. The resulting mixture was stirred for 1 h then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 36-60% MeCN / 1% aqueous NH ₃ ; Detector 220 nm; to afford 5-cyano-N-[2,4-difluoro-3-[3-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-sulfonamide (40 mg, 50% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 508 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.96 (s, 1H), 10.51 (s, 1H), 9.57 (d, J = 7.5 Hz, 1H), 8.94 (d, J = 2.2 Hz, 1H), 8.50 (d, J = 2.2 Hz, 1H), 7.76 (s, 1H), 7.69 (s, 1H), 7.42-7.15 (m, 4H), 6.82 (dd, J = 7.5, 1.6 Hz, 1H), 4.03 (s, 3H)

Example 56: Synthesis of 5-chloro-N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 41) Compound 41 Synthesis of 41-a: N-[(4-chloro-3-fluoropyridin-2-yl)methyl]-1H-imidazole-2-car boxamide [0449] To a stirred solution of 1-(4-chloro-3-fluoropyridin-2-yl)methanamine (3.5 g, 21 mmol, 1 equiv) and TEA (4.4 g, 43 mmol, 2 equiv) in DCM (50 mL) was added a solution of 1H-imidazole-2-carbonyl chloride (3.13 g, 23 mmol, 1.1 equiv) in DCM (10 mL) at 0 °C. The resulting solution was stirred for 1 h at room temperature. The reaction mixture was diluted with water (100 mL) and extracted with DCM (3 x 300 mL). The combined organics were washed with brine (2 x 20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure to afford N-[(4-chloro-3-fluoropyridin-2-yl)methyl]-1H-imidazole-2- carboxamide (4 g, crude) as a yellow solid which was used in the next step without further purification. LCMS (ES, m/z): [M+H] ⁺ : 255 Synthesis of 41-b: 2-[7-chloro-8-fluoroimidazo[1,5-a]pyridin-3-yl]-1H-imidazole [0450] N-[(4-chloro-3-fluoropyridin-2-yl)methyl]-1H-imidazole-2-car boxamide (3 g, 12 mmol, 1 equiv) was dissolved in POCl ₃ (20 mL) and stirred for 5 h at 110 °C. The mixture was allowed to cool and was concentrated under vacuum. The residue was carefully quenched by addition of saturated aqueous NaHCO ₃ (100 mL). The resulting mixture was extracted with EA (3 x 100 mL), and the combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford 2-[7- chloro-8-fluoroimidazo[1,5-a]pyridin-3-yl]-1H-imidazole (900 mg, 32% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 237 Synthesis of 41-c: 2-[7-chloro-8-fluoroimidazo[1,5-a]pyridin-3-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole [0451] To a stirred solution of 2-[7-chloro-8-fluoroimidazo[1,5-a]pyridin-3-yl]-1H-imidazole (900 mg, 3.8 mmol, 1 equiv) in THF (20 mL) was added NaH (304 mg, 7.6 mmol, 2 equiv, 60% in oil) in portions at 0 °C. The resulting mixture was stirred for 1 h at 0 °C, then SEM- Cl (951 mg, 5.7 mmol, 1.5 equiv) was added and the mixture stirred in an ice bath for 1 h. The reaction was quenched with water (50 mL) at 0 °C, and the resulting mixture was extracted with EA (3 x 100 mL). The combined organics were washed with brine (3 x 20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (10:1) to afford 2-[7- chloro-8-fluoroimidazo[1,5-a]pyridin-3-yl]-1-[[2-(trimethyls ilyl)ethoxy]methyl]imidazole (1 g, 71% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 367 Synthesis of 41-d: 2,4-difluoro-3-[8-fluoro-3-(1-[[2-(trimethylsilyl)ethoxy]met hyl]imidazol- 2-yl)imidazo[1,5-a]pyridin-7-yl]aniline [0452] To a solution of 2-[7-chloro-8-fluoroimidazo[1,5-a]pyridin-3-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (1.4 g, 3.8 mmol, 1 equiv), 2,4-difluoro-3-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (973 mg, 3.8 mmol, 1 equiv), and K ₂ CO ₃ (1 g, 7.6 mmol, 2 equiv) in dioxane (20 mL) and H ₂ O (5 mL) were added XPhos (181 mg, 0.38 mmol, 0.1 equiv) and XPhos Pd G3 (322 mg, 0.38 mmol, 0.1 equiv) at room temperature under nitrogen atmosphere. The resulting solution was stirred at 100 °C under nitrogen atmosphere for 5 h. After cooling to room temperature, water (100 mL) was added and the mixture extracted with ethyl acetate (3 x 200 mL). The combined organics were washed with brine (2 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure to give a crude product. This was purified by column chromatography over silica gel (eluent: PE:EA =4:1) to afford 2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]aniline (800 mg, 45% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 460 Synthesis of 41-e: 5-chloro-N-(2,4-difluoro-3-(8-fluoro-3-(1-((2- (trimethylsilyl)ethoxy)methyl)-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl)phenyl)-2- methoxypyridine-3-sulfonamide [0453] To a solution of 2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]aniline (150 mg, 0.3 mmol, 1 equiv) and pyridine (77 mg, 0.9 mmol, 3.00 equiv) in DCM (5 mL) was added 5- chloro-2-methoxypyridine-3-sulfonyl chloride (94 mg, 0.39 mmol, 1.2 equiv) in portions at room temperature. The resulting solution was stirred for 1 h at room temperature. The resulting mixture was concentrated under reduced pressure and the residue purified by column chromatography over silica gel (eluent: PE:EA =5:1) to afford 5-chloro-N-[2,4- difluoro-3-[8-fluoro-3-(1-[[2-(trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-sulfonamide (100 mg, 46% yield) as a colorless oil. LCMS (ES, m/z): [M+H] ⁺ : 665 Synthesis of Compound 41: 5-chloro-N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0454] To a stirred solution of 5-chloro-N-[2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide (70 mg, 0.1 mmol, 1 equiv) in DCM (4 mL) was added TFA (1 mL) dropwise at room temperature. The resulting mixture was stirred for 1 h at room temperature, then concentrated under reduced pressure. The residue was purified by prep- HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 35-65% MeCN/0.1% aqueous formic acid; Detector, 220 nm; to afford 5- chloro-N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2-yl)imida zo[1,5-a]pyridin-7-yl]phenyl]- 2-methoxypyridine-3-sulfonamide (40 mg, 71% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 535 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.11 (s, 1H), 10.47 (s, 1H), 9.44 (d, J = 7.4 Hz, 1H), 8.52 (d, J = 2.6 Hz, 1H), 8.08 (d, J = 2.6 Hz, 1H), 7.87 (s, 1H), 7.46 (td, J = 8.9, 5.8 Hz, 1H), 7.38- 7.15 (m, 3H), 6.85 (t, J = 6.9 Hz, 1H), 3.91 (s, 3H). Example 57: Synthesis of 5-cyano-N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 42) Compound 42 Synthesis of 42-a: 5-cyano-N-[2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide- [0455] To a solution of 2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]aniline (150 mg, 0.3 mmol, 1 equiv) and pyridine (77 mg, 0.9 mmol, 3 equiv) in DCM (5 mL) was added 5-cyano- 2-methoxypyridine-3-sulfonyl chloride (91 mg, 0.3 mmol, 1.2 equiv) in portions at room temperature. The resulting solution was stirred for 1 h at room temperature. The mixture was concentrated and the residue purified by column chromatography over silica gel (eluent: PE:EA = 4:1) to afford 5-cyano-N-[2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide (100 mg, 46% yield) as a yellow solid. Synthesis of Compound 42: 5-cyano-N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0456] To a stirred solution of 5-cyano-N-[2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-2- methoxypyridine-3-sulfonamide (80 mg) in DCM (4 mL) was added TFA (1 mL) dropwise at room temperature. The resulting mixture was stirred for 1 h at room temperature then concentrated under reduced pressure. The residue was purified by prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase 25-60% MeCN / 0.1% aqueous formic acid; Detector 220 nm; to afford 5-cyano-N-[2,4-difluoro-3-[8- fluoro-3-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin-7-yl]phenyl ]-2-methoxypyridine-3- sulfonamide (30 mg, 46% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 526 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.11 (s, 1H), 10.56 (s, 1H), 9.43 (d, J = 7.3 Hz, 1H), 8.94 (d, J = 2.2 Hz, 1H), 8.49 (d, J = 2.3 Hz, 1H), 7.86 (s, 1H), 7.46 (td, J = 9.0, 5.9 Hz, 1H), 7.33- 7.14 (m, 2H), 6.85 (t, J = 6.9 Hz, 1H), 4.01 (s, 3H).

Example 58: Synthesis of N-[3-[1-(4-cyano-1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6- yl]-2,4-difluorophenyl]- 5-chloro-2-methoxypyridine-3-sulfonamide (Compound 43) Compound 43 Synthesis of 43-a: 1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole-4-carbonitrile [0457] Into a 100 mL 3-necked round-bottom flask were added 1H-imidazole-4-carbonitrile (2 g, 21.4 mmol, 1 equiv) in DMF (20 mL). To the above mixture was added 60% NaH (1.55 g, 64.4 mmol, 3 equiv) in portions at 0 °C. The resulting mixture was stirred for 30 min at 0 °C, and [2-(chloromethoxy)ethyl]trimethylsilane (3.9 g, 23.6 mmol, 1.1 equiv) was added dropwise at 0 °C. The reaction was stirred for 1 h at room temperature, then quenched with water (100 ml). The resulting mixture was diluted with more water (100 mL), and extracted with EtOAc (3 x 100 mL). The combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, with PE/EtOAc (1:1) to afford 1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole-4-carbonitrile (3.2 g, 67% yield) as a colorless oil. LCMS (ES, m/z): [M+H] ⁺ : 224. Synthesis of 43-b: 2-bromo-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole-4-carb onitrile [0458] Into a 250 mL round-bottom flask were added 1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole-4-carbonitrile (3.2 g, 14.3 mmol, 1 equiv), NBS (2.8 g, 15.7 mmol, 1.1 equiv), CCl ₄ (80 mL) and AIBN (0.24 g, 1.4 mmol, 0.1 equiv). The resulting mixture was stirred for 4 h at 60 °C. The resulting mixture was concentrated under reduced pressure, and the residue purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 2-bromo-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole-4- carbonitrile (3.7 g, 85% yield) as a colorless oil. LCMS (ES, m/z): [M+H] ⁺ : 302, 304. Synthesis of 43-c: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl] imidazole-4-carbonitrile [0459] Into a 40 mL vial were added 2-bromo-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole-4-carbonitrile (2.8 g, 9.2 mmol, 1 equiv), hexamethyldistannane (3.37 g, 10.3 mmol, 1.1 equiv), Pd(dppf)Cl ₂ (0.68 g, 0.9 mmol, 0.1 equiv) and dioxane (10 mL). The resulting mixture was stirred for 4 h at 100 °C under nitrogen atmosphere, then concentrated under reduced pressure. To the residue was added Pd(PPh ₃ ) ₂ Cl ₂ (0.65 g, 0.9 mmol, 0.1 equiv), 6-bromo-1-iodoimidazo[1,5-a]pyridine (1 g, 3.1 mmol, 0.34 equiv) and DMF (1 mL). The resulting mixture was stirred for 16 h at 100 °C under nitrogen atmosphere. The mixture was allowed to cool to room temperature and was diluted with water (100 mL). This was extracted with EtOAc (3 x 100 mL), and the combined organics were washed with brine (3 x 100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (3:1) to afford 2-[6-bromoimidazo[1,5-a]pyridin-1- yl]-1-[[2-(trimethylsilyl)ethoxy] methyl]imidazole-4-carbonitrile (210 mg, 5.4% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 418, 420. Synthesis of 43-d: 2-[6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridin-1-yl] -1-[[2- (trimethylsilyl) ethoxy]methyl]imidazole-4-carbonitrile [0460] Into a 40 mL vial were added 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy] methyl]imidazole-4-carbonitrile (220 mg, 0.5 mmol, 1 equiv), 2,4- difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)anil ine (395 mg, 1.5 mmol, 3.0 equiv), Pd(dppf)Cl ₂ (42 mg, 0.06 mmol, 0.11 equiv), K ₂ CO ₃ (220 mg, 1.6 mmol, 3 equiv), dioxane (5 mL) and H ₂ O (0.5 mL). The resulting mixture was stirred for 16 h at 80 °C under nitrogen atmosphere, then was diluted with water (100 mL). This was extracted with EtOAc (3 x 100 mL), and the combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (3:2) to afford 2-[6-(3-amino-2,6- difluorophenyl)imidazo[1,5-a]pyridin-1-yl]-1-[[2-(trimethyls ilyl)ethoxy]methyl]imidazole-4- carbonitrile (125 mg, 51% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 467. Synthesis of 43-e: 5-chloro-N-[3-[1-(4-cyano-1-[[2-(trimethylsilyl)ethoxy]methy l]imidazol- 2-yl) imidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-2-methoxypyr idine-3-sulfonamide [0461] Into an 8 mL vial were added 2-[6-(3-amino-2,6-difluorophenyl)imidazo[1,5- a]pyridin-1-yl]-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol e-4-carbonitrile (50 mg, 0.24 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (39 mg, 0.16 mmol, 1.5 equiv), pyridine (40 mg, 0.51 mmol, 4.7 equiv) and DCM (2 mL). The resulting mixture was stirred overnight at room temperature, then was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (3:2) to afford 5-chloro-N-[3-[1-(4-cyano-1-[[2-(trimethylsilyl)ethoxy]methy l]imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-2-methoxy pyridine-3-sulfonamide (52 mg, 33% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 672. Synthesis of Compound 43: N-[3-[1-(4-cyano-1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl ]- 2,4-difluorophenyl]- 5-chloro-2-methoxypyridine-3-sulfonamide [0462] Into an 8 mL vial were added 5-chloro-N-[3-[1-(4-cyano-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 2-methoxypyridine-3-sulfonamide (47 mg, 0.07 mmol, 1 equiv) and TFA (2 mL). The resulting mixture was stirred for 1 h at 60 °C, then was concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase: 30-65% MeCN/ 0.1% aqueous formic acid; Flow rate: 90 mL/min; to afford N-[3-[1-(4-cyano-1H-imidazol-2-yl)imidazo[1,5-a]pyridin- 6-yl]-2,4-difluorophenyl]-5-chloro-2-methoxypyridine-3-sulfo namide (13.5 mg, 42% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 542. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.40 (s, 1H), 10.46 (s, 1H), 8.60 (m, 2H), 8.52 (d, J = 2.6 Hz, 1H), 8.20 (d, J = 9.4 Hz, 1H), 8.13 (d, J = 2.5 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.44- 7.34 (m, 1H), 7.27 (t, J = 9.3 Hz, 1H), 6.97 (d, J = 9.5 Hz, 1H), 3.93 (s, 3H). Example 59: Synthesis of N-[3-[1-(4-cyano-1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6- yl]-2,4-difluorophenyl] -5-fluoro-2-methylpyridine-3-sulfonamide (Compound 44) Compound 44 Synthesis of 44-a: N-[3-[1-(4-cyano-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazo l-2- yl)imidazo[1,5-a] pyridin-6-yl]-2,4-difluorophenyl]-5-fluoro-2-methylpyridine- 3- sulfonamide [0463] Into an 8 mL vial were added 2-[6-(3-amino-2,6-difluorophenyl)imidazo[1,5- a]pyridin-1-yl]-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol e-4-carbonitrile (50 mg, 0.11 mmol, 1 equiv), 5-fluoro-2-methylpyridine-3-sulfonyl chloride (67 mg, 0.32 mmol, 3 equiv), pyridine (42 mg, 0.53 mmol, 5 equiv) and DCM (2 mL). The resulting mixture was stirred overnight at room temperature. The mixture was concentrated under reduced pressure and the residue was purified by silica gel column chromatography, eluting with PE/EtOAc (3:2) to afford N-[3-[1-(4-cyano-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazo l-2-yl)imidazo[1,5- a]pyridin-6-yl]-2,4-difluorophenyl]-5-fluoro-2-methylpyridin e-3-sulfonamide (45 mg, 66% yield) as a light yellow solid. LCMS (ES, m/z): [M-H]-: 640. Synthesis of Compound 44: N-[3-[1-(4-cyano-1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl ]- 2,4-difluorophenyl] -5-fluoro-2-methylpyridine-3-sulfonamide [0464] Into an 8 mL vial were added N-[3-[1-(4-cyano-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 5-fluoro-2-methylpyridine-3-sulfonamide (40 mg, 0.06 mmol, 1 equiv) and TFA (2 mL). The resulting mixture was stirred for 1 h at 60 °C, then concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase 25-65% MeCN/0.1% aqueous formic acid; Flow rate: 90 mL/min; Detector 220 nm; to afford N-[3-[1-(4-cyano-1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-5-fluoro- 2-methylpyridine-3-sulfonamide (13.5 mg, 42% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 510. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.40 (s, 1H), 10.79 (s, 1H), 8.75 (d, J = 2.8 Hz, 1H), 8.59 (s, 2H), 8.19 (d, J = 9.5 Hz, 1H), 8.13 (d, J = 2.5 Hz, 1H), 7.96 (dd, J = 8.2, 2.8 Hz, 1H), 7.37 (td, J = 8.9, 5.9 Hz, 1H), 7.27 (dd, J = 9.9, 8.5 Hz, 1H), 6.93 (d, J = 9.4 Hz, 1H), 2.78 (d, J = 1.2 Hz, 3H).

Example 60: Synthesis of N-[3-[1-(4-chloro-1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6- yl]-2,4-difluorophenyl] -5-fluoro-2-methoxypyridine-3-sulfonamide (Compound 45) Compound 45 Synthesis of 45-a: 1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole-4-carbonitrile [0465] Into a 100 mL 3-necked round-bottom flask were added 4-chloro-1H-imidazole (2 g, 20 mmol, 1 equiv) and DMF (20 mL). To the above mixture was added 60% NaH (1.4 g, 58.5 mmol, 3 equiv) in portions at 0 °C. The resulting mixture was stirred for additional 30 min at 0 °C, then [2-(chloromethoxy)ethyl]trimethylsilane (3.58 g, 21.4 mmol, 1.1 equiv) was added dropwise at 0 °C. The resulting mixture was stirred for 1 h at room temperature, then quenched with water (100 mL). The resulting mixture was diluted with water (100 mL) and extracted with EtOAc (3 x 100 mL). The combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 1- [[2-(trimethylsilyl)ethoxy]methyl]imidazole-4-carbonitrile (3.2 g, 67% yield) as a colorless oil. LCMS (ES, m/z): [M-H]-: 233 Synthesis of 45-b: 3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol- 2- yl)imidazo[1,5-a] pyridin-6-yl]-2,4-difluoroaniline [0466] Into a 100 mL 3-necked round-bottom flask were added 4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (1.6 g, 6.8 mmol, 1 equiv) and THF (20 mL). To this was added 2.5M n-BuLi (3.3 mL, 8.2 mmol, 1.2 equiv) dropwise at -78 °C. The resulting mixture was stirred for 1 h at -78 °C, then 1M ZnCl ₂ in Et ₂ O (8.1 mL, 8.1 mmol, 1.2 equiv) was added and this mixture stirred for 1 h, allowing it to warm to room temperature.2,4- Difluoro-3-[1-iodoimidazo[1,5-a]pyridin-6-yl]aniline (1 g, 2.7 mmol, 0.39 equiv) and Pd(PPh ₃ ) ₄ (790 mg, 0.68 mmol, 0.1 equiv) were added, and this stirred for 1 h at 60 °C. The resulting mixture was diluted with water (100 mL) and extracted with EtOAc (3 x 100 mL). The combined organics were washed with brine (3x50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (3:2) to afford 3-[1-(4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluoroaniline (1.1 g, 34% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 476. Synthesis of 45-c: N-[3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidaz ol-2- yl)imidazo [1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-5-fluoro-2-methoxyp yridine-3- sulfonamide [0467] Into an 8 mL vial were added 3-[1-(4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluoroaniline (150 mg, 0.3 mmol, 1 equiv), 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (106 mg, 0.47 mmol, 1.5 equiv), DCM (2 mL) and pyridine (124 mg, 1.56 mmol, 5 equiv). The resulting mixture was stirred overnight at room temperature. The mixture was concentrated under vacuum and the residue purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford N-[3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidaz ol-2- yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-5-fluoro- 2-methoxypyridine-3- sulfonamide (120 mg, 57% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 665. Synthesis of Compound 45: N-[3-[1-(4-chloro-1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-y l]- 2,4-difluorophenyl] -5-fluoro-2-methoxypyridine-3-sulfonamide [0468] Into an 8 mL vial were added N-[3-[1-(4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 5-fluoro-2-methoxypyridine-3-sulfonamide (110 mg, 0.16 mmol, 1 equiv) and TFA (2 mL). The resulting mixture was stirred for 2 h at 60 °C, then concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm*5 um; Mobile Phase 30-70% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; to afford N-[3-[1-(4-chloro-1H-imidazol-2-yl)imidazo[1,5-a]pyridin- 6-yl]-2,4-difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfo namide (44 mg, 50% yield) as a light green solid. LCMS (ES, m/z): [M+H] ⁺ : 535. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.73 (s, 1H), 10.44 (s, 1H), 8.54 (s, 2H), 8.42 (d, J = 3.0 Hz, 1H), 8.14 (d, J = 9.5 Hz, 1H), 8.00 (dd, J = 7.4, 3.0 Hz, 1H), 7.41-7.27 (m, 1H), 7.18 (d, J = 2.2 Hz, 2H), 6.90 (d, J = 9.4 Hz, 1H), 3.90 (s, 3H). Example 61: Synthesis of N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide (Compound 46) Synthesis of Compound 46: N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide [0469] Into an 8 mL vial was placed 2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5- a]pyridin-6-yl]aniline (80 mg, 0.25 mmol, 1 equiv), pyridine (2 mL) and 5-fluoro-2- methoxypyridine-3-sulfonyl chloride (83 mg, 0.4 mmol, 1.5 equiv) at room temperature. The resulting solution was stirred for 1 h at room temperature. The resulting mixture was concentrated under vacuum and the residue purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 20-55% MeCN / 0.1% aqueous formic acid; to afford N-[2,4-difluoro-3-[1-(1-methylpyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide (50 mg, 40% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 515 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.42 (s, 1H), 8.46 (d, J = 6.6 Hz, 3H), 8.10 (d, J = 9.4 Hz, 1H), 8.03 (dd, J = 7.4, 3.0 Hz, 1H), 7.73 (d, J = 2.3 Hz, 1H), 7.36 (d, J = 6.1 Hz, 1H), 7.24 (d, J = 9.2 Hz, 1H), 6.80-6.71 (m, 1H), 6.62 (d, J = 2.2 Hz, 1H), 3.92 (s, 6H). Example 62: Synthesis of N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide (Compound 47) Compound 47 Synthesis of 47-a: N-[2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide [0470] To a solution of 2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]aniline (150 mg, 0.3 mmol, 1 equiv) and pyridine (77 mg, 0.9 mmol, 3 equiv) in DCM (5 mL) was added 5-fluoro- 2-methoxypyridine-3-sulfonyl chloride (88 mg, 0.39 mmol, 1.2 equiv) in portions at room temperature. The resulting solution was stirred for 1 h, then concentrated. The residue was purified by column chromatography over silica gel (eluent: PE:EA = 4:1) to afford N-[2,4- difluoro-3-[8-fluoro-3-(1-[[2-(trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide (100 mg, 47% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 649 Synthesis of Compound 47: N-[2,4-difluoro-3-[8-fluoro-3-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-7-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide [0471] To a stirred solution of N-[2,4-difluoro-3-[8-fluoro-3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (70 mg, 0.1 mmol, 1 equiv) in DCM (4 mL) was added TFA (1 mL) dropwise at room temperature. The resulting mixture was stirred for 1 h then concentrated under reduced pressure. The residue was purified by prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 30-65% MeCN/ 0.1% aqueous formic acid; Detector, 220 nm; to afford N-[2,4-difluoro-3-[8-fluoro-3- (1H-imidazol-2-yl)imidazo[1,5-a]pyridin-7-yl]phenyl]-5-fluor o-2-methoxypyridine-3- sulfonamide (30 mg, 53% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 519 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.11 (s, 1H), 10.46 (s, 1H), 9.44 (dd, J = 7.3, 0.9 Hz, 1H), 8.45 (d, J = 3.0 Hz, 1H), 8.01 (dd, J = 7.4, 3.0 Hz, 1H), 7.86 (d, J = 0.9 Hz, 1H), 7.44 (td, J = 8.9, 5.9 Hz, 1H), 7.36-7.13 (m, 3H), 6.85 (t, J = 6.9 Hz, 1H), 3.90 (s, 3H).

Example 63: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2- yl)imidazo[1,5-a]pyridine -6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 48) Compound 48 Synthesis of 48-a: 5-methyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole [0472] To a solution of 4-methylimidazole (5 g, 61 mmol, 1 equiv) in DMF (50 mL) was added NaH (4.9 g, 122 mmol, 2 equiv, 60% in oil) at 0 °C. The mixture was stirred for 15 min, then SEMCl (12.2 g, 73 mmol, 1.2 equiv) was added and the mixture was allowed to warm to room temperature over 16 h. The reaction mixture was quenched by water (25 mL) and extracted with DCM (3 x 25 mL). The combined organics were washed with water and brine (50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (10/1) to afford 5-methyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole (8 g, 62% yield) as a light yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 213. Synthesis of 48-b: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole [0473] In a 50 mL round bottom flask, to a solution of 5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (197 mg, 0.93 mmol, 3 equiv) in THF (2 mL) was added dropwise n-butyllithium solution (2.5 M in hexane, 0.37 mL, 0.93 mmol, 3 equiv) at - 78 °C under N ₂ atmosphere. The reaction mixture was stirred at -78 °C for 30 mins, then ZnCl ₂ (1 M in Et ₂ O, 1 mL, 1 mmol, 3.3 equiv) was added dropwise at -78 °C. The resulting mixture was stirred for 30 mins at room temperature, then a solution of 6-bromo-1- iodoimidazo[1,5-a]pyridine (100 mg, 0.3 mmol, 1 equiv) and Pd(PPh ₃ ) ₄ (71 mg, 0.062 mmol, 0.2 equiv) in 0.5 mL THF was added dropwise. The resulting mixture was stirred for 60 mins at 60 °C, then quenched with sat. NH ₄ Cl solution (2 mL). The mixture was extracted with EtOAc (2 x 30 mL) and the combined organics were washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ , and concentrated under vacuum .The residue was purified by silica gel column chromatography, eluting with PE/EA (3/1) to afford 2-[6-bromoimidazo[1,5- a]pyridin-1-yl]-5-methyl-1-[[2-(trimethylsilyl)ethoxy]methyl ]imidazole (86 mg, 45% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 407. Synthesis of 48-c: 2,4-difluoro-3-[1-(5-methyl-1-[[2-(trimethylsilyl)ethoxy]met hyl]imidazol- 2-yl)imidazo [1,5-a]pyridin-6-yl]aniline [0474] To a solution of 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (76 mg, 0.19 mmol, 1 equiv) and 2,4-difluoro-3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (72 mg, 0.28 mmol, 1.5 equiv) in dioxane (2 mL) and H ₂ O (0.2 mL) were added K ₂ CO ₃ (77 mg, 0.56 mmol, 3 equiv) and Pd(dppf)Cl ₂ (14 mg, 0.019 mmol, 0.1 equiv). After stirring for 2 h at 80 °C under a nitrogen atmosphere, the resulting mixture was concentrated under reduced pressure. The residue was purified by Prep-TLC/silica gel column chromatography, eluting with PE/EA (1/1) to afford 2,4-difluoro-3-[1-(5-methyl-1-[[2-(trimethylsilyl)ethoxy]met hyl]imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]aniline (53 mg, 62% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 456. Synthesis of 48-d: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0475] To a stirred solution of 2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (43 mg, 0.09 mmol, 1 equiv) and pyridine (30 mg, 0.38 mmol, 4 equiv) in DCM (2 mL) was added 5- chloro-2-methoxypyridine-3-sulfonyl chloride (46 mg, 0.19 mmol, 2 equiv) in portions at room temperature. The resulting mixture was stirred 4 h, then diluted with water (2 mL). This was extracted with CH ₂ Cl ₂ (3 x 10 mL), and the combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE(0-50%) to afford 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-1-[[2-(trimethylsily l)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypy ridine-3-sulfonamide (52 mg, 84% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 661. Synthesis of Compound 48: 5-chloro-N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2- yl)imidazo[1,5-a]pyridine -6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0476] To a stirred mixture of 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (55 mg, 0.08 mmol, 1 equiv) was added DCM (1 mL) and TFA (0.5 mL) at room temperature. The resulting mixture was stirred for 30 min at 40 °C. The resulting mixture was concentrated under vacuum and the residue neutralized to pH 7 with ammonia. This was purified by Prep-HPLC: Column: Sunfire Prep C ₁₈ OBD, 50 x 250 mm, 5 um-10 nm; Mobile Phase: 18-45% 1:1 MeOH:MeCN/ 0.1% aqueous ammonia; Flow rate: 90 mL/min; to afford 5-chloro-N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (17 mg, 39% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 531. ¹ H NMR (300 MHz, DMSO-d6): δ 8.50 (m, 3H), 8.20 (d, J = 9.4 Hz, 1H), 8.08 (d, J = 2.6 Hz, 1H), 7.36 (td, J = 8.9, 5.9 Hz, 1H), 7.29-7.17 (m, 1H), 6.86-6.73 (m, 2H), 3.92 (s, 3H), 2.21 (s, 3H). Example 64: Synthesis of 5-chloro-N-(2,4-difluoro-3-[1-[4-(hydroxymethyl)-3H- imidazol-2-yl]imidazo[1,5-a] pyridin-6-yl]phenyl)-2-methoxypyridine-3-sulfonamide (Compound 49) Compound 49 Synthesis of 49-a: 4-[[(tert-butyldiphenylsilyl)oxy]methyl]-1H-imidazole [0477] To a stirred mixture of 3H-imidazol-4-ylmethanol hydrochloride (5 g, 37 mmol, 1 equiv) and Et ₃ N (7.5 g, 74 mmol, 2 equiv) in DCM (50 mL) was added tert- butyl(chloro)diphenylsilane (15.3 g, 55 mmol, 1.5 equiv) dropwise at 0-5 °C. The resulting mixture was stirred overnight at room temperature, then diluted with water (100 mL). The resulting mixture was extracted with DCM (3 x 100 mL) and the combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with 0-50% EtOAc/PE to afford 4-[[(tert-butyldiphenylsilyl)oxy]methyl]-1H-imidazole (6.4 g, 51% yield) as a white solid. Synthesis of 49-b: 5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole [0478] To a stirred solution of 4-[[(tert-butyldiphenylsilyl)oxy]methyl]-3H-imidazole(6.5 g, 19.3 mmol, 1 equiv) in DMF (65 mL) was added NaH (1.55 g, 38.6 mmol, 2 equiv, 60% in oil) in portions at 0-5 °C. The resulting mixture was stirred for 10 min then SEM-Cl (4.83 g, 28.9 mmol, 1.5 equiv) was added dropwise at 0-5 °C. The resulting mixture was stirred for 2 h at room temperature, then diluted with water (200 mL). This was extracted with EtOAc (3 x 200 mL) and the combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (3:1) to afford 5-[[(tert- butyldiphenylsilyl)oxy]methyl]-1-[[2-(trimethylsilyl)ethoxy] methyl]imidazole (4 g, 44% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ :467. Synthesis of 49-c: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-[[(tert- butyldiphenylsilyl)oxy]methyl] -1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole [0479] To a stirred solution of 5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (4.34 g, 9.3 mmol, 3 equiv) in THF (40 mL) was added n-BuLi (595 mg, 9.3 mmol, 3 equiv) at -78 °C under nitrogen atmosphere and this was stirred for 30 min at -78 °C. ZnCl ₂ (1.27 g, 9.3 mmol, 3 equiv) was added at -78 °C, then the solution was warmed to room temperature and stirred for additional 30 min. Pd(PPh ₃ ) ₄ (715 mg, 0.62 mmol, 0.2 equiv) and 6-bromo-1-iodoimidazo[1,5-a]pyridine (1 g, 3.1 mmol, 1 equiv) were added and the resulting mixture was stirred for 1 h at 50 °C. The mixture was allowed to cool to room temperature and was quenched with water (100 mL). The resulting mixture was extracted with EtOAc (2 x 50 mL), and the combined organics were washed with brine (50 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (80:20) to afford 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-[[(tert-butyldipheny lsilyl)oxy]methyl]-1- [[2-(trimethylsilyl) ethoxy]methyl]imidazole (850 mg, 41% yield) as a red oil. LCMS (ES, m/z): [M+H] ⁺ :661, 663 Synthesis of 49-d: 3-[1-(5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluoroanilin e [0480] Into a 40 mL vial were added 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-[[(tert- butyldiphenylsilyl)oxy]methyl]-1-[[2-(trimethylsilyl)ethoxy] methyl]imidazole (870 mg, 1.3 mmol, 1 equiv), dioxane (9 mL) and H ₂ O (1 mL). To the stirred solution was added 2,4- difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)anil ine (503 mg, 1.9 mmol, 1.5 equiv), K ₂ CO ₃ (545 mg, 3.9 mmol, 3 equiv) and Pd(dtbpf)Cl ₂ (85 mg, 0.13 mmol, 0.1 equiv) at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 1 h at 80 °C under nitrogen atmosphere, then cooled to room temperature.2,4-Difluoro-3-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (503 mg, 1.972 mmol, 1.5 equiv) and Pd(dtbpf)Cl ₂ (85 mg, 0.13 mmol, 0.1 equiv) were added and the mixture was stirred for an additional 1 h at 80 °C. The reaction was allowed to cool and quenched with water (40 mL). The resulting mixture was extracted with EtOAc (3 x 30 mL), and the combined organics washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 3-[1-(5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a] pyridin-6-yl]-2,4-difluoroaniline (600 mg, 64% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 710. Synthesis of 49-e: N-[3-[1-(5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]-2,4- difluorophenyl]-5-chloro-2-methoxypyridine-3-sulfonamide [0481] Into a 4 mL vial were added 3-[1-(5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluoroaniline (120 mg, 0.17 mmol, 1 equiv) and DCM (4 mL). To the stirred solution was added pyridine (40 mg, 0.5 mmol, 3 equiv) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (61 mg, 0.25 mmol, 1.5 equiv) and the resulting mixture was stirred overnight at room temperature. The reaction was quenched with water (20 mL), and extracted with EtOAc (3 x 20 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (40:60) to afford N-[3-[1-(5-[[(tert- butyldiphenylsilyl)oxy]methyl]-1-[[2-(trimethylsilyl)ethoxy] methyl]imidazole-2- yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-5-chloro- 2-methoxypyridine-3- sulfonamide (120 mg, 78% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 915. Synthesis of Compound 49: 5-chloro-N-(2,4-difluoro-3-[1-[4-(hydroxymethyl)-3H-imidazol - 2-yl]imidazo[1,5-a] pyridin-6-yl]phenyl)-2-methoxypyridine-3-sulfonamide [0482] Into a 20 mL vial were added N-[3-[1-(5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1- [[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]-2,4- difluorophenyl]-5-chloro-2-methoxypyridine-3-sulfonamide (140 mg, 0.15 mmol, 1 equiv) and 1 M TBAF in THF (4 mL). The resulting mixture was stirred overnight at 80 °C, then concentrated. The crude product was purified by Prep-HPLC with the following conditions: Column: welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Flowrate: 90 mL/min; Mobile Phase: 5-40% MeCN / 0.05% aqueous formic acid; to afford 5-chloro-N-(2,4-difluoro-3-[1- [4-(hydroxymethyl)-3H-imidazol-2-yl]imidazo[1,5-a]pyridin-6- yl]phenyl)-2- methoxypyridine-3-sulfonamide (25 mg, 30% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 547 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.52 (m, 3H), 8.23 (d, J = 9.4 Hz, 1H), 8.11-8.05 (m, 1H), 7.37 (td, J = 8.8, 5.9 Hz, 1H), 7.25 (td, J = 9.2, 1.6 Hz, 1H), 6.93 (s, 1H), 6.83 (dd, J = 9.4, 1.6 Hz, 1H), 4.84 (s, 1H), 4.45 (d, J = 3.7 Hz, 2H), 3.93 (s, 3H). Example 65: Synthesis of N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5-fluoro-2-methylpyridine-3-sulfonamide (Compound 50) Compound 50 Synthesis of 50-a: N-[2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide [0483] To a stirred solution of 2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (200 mg, 0.44 mmol, 1 equiv) and pyridine (139 mg, 1.76 mmol, 4 equiv) in DCM (2 mL) was added 5-fluoro-2-methylpyridine-3-sulfonyl chloride (184 mg, 0.88 mmol, 2 equiv) in portions at room temperature. The resulting mixture was stirred for 4 h at room temperature, then diluted with water (2 mL) and extracted with CH ₂ Cl ₂ (3 x 10 mL). The combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE(0-50%) to afford N-[2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide (163 mg, 59% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 629. Synthesis of Compound 50: N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5-fluoro-2-methylpyridine-3-sulfonamide [0484] To a stirred mixture of N-[2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide (130 mg, 0.21 mmol, 1 equiv) was added DCM (1 mL) and TFA (0.5 mL) at room temperature. The resulting mixture was stirred for 30 min at 40 °C, then concentrated under vacuum. The residue was neutralized to pH 7 with 5% aqueous NH ₃ , and was purified by Prep-HPLC: Column, Sunfire Prep C18 OBD, 50*250 mm, 5 um-10 nm; Mobile Phase 9-26% 1:1 MeOH:MeCN / 0.1% aqueous ammonia; Flow rate: 90 mL/min; to afford N-[2,4-difluoro-3-[1-(4-methyl- 3H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]- 5-fluoro-2-methylpyridine-3-sulfonamide (10 mg, 10% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 499. ¹ H NMR (300 MHz, DMSO-d ₆ ): δ 11.95-11.68 (br, 1H), 8.70 (d, J = 2.8 Hz, 1H), 8.51 (d, J = 4.8 Hz, 2H), 8.20 (d, J = 9.5 Hz, 1H), 7.95 (dd, J = 8.3, 2.8 Hz, 1H), 7.33 (td, J = 8.8, 5.6 Hz, 1H), 7.20 (t, J = 9.2 Hz, 1H), 6.84 (s, 2H), 2.78 (s, 3H), 2.23 (s, 3H). Example 66: Synthesis of N-(2,4-difluoro-3-[1-[4-(hydroxymethyl)-3H-imidazol-2- yl]imidazo[1,5-a] pyridin-6-yl]phenyl)-5-fluoro-2-methylpyridine-3-sulfonamide (Compound 51) Compound 51 Synthesis of 51-a: N-[3-[1-(5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]-2,4- difluorophenyl]-5-fluoro-2-methylpyridine-3-sulfonamide [0485] Into a 20 mL vial were added 3-[1-(5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2- (trimethylsilyl)ethoxy] methyl]imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluor oaniline (150 mg, 0.21 mmol, 1 equiv) and DCM (5 mL), followed by pyridine (83 mg, 1.06 mmol, 5 equiv) and 5-fluoro-2-methylpyridine-3-sulfonyl chloride (133 mg, 0.63 mmol, 3 equiv). The resulting mixture was stirred overnight at room temperature, then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford N-[3- [1-(5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2-(trimethy lsilyl)ethoxy]methyl]imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-5-fluoro- 2-methylpyridine-3-sulfonamide (100 mg, 54% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 883. Synthesis of Compound 51: N-(2,4-difluoro-3-[1-[4-(hydroxymethyl)-3H-imidazol-2- yl]imidazo[1,5-a] pyridin-6-yl]phenyl)-5-fluoro-2-methylpyridine-3-sulfonamide [0486] Into a 20 mL vial were added N-[3-[1-(5-[[(tert-butyldiphenylsilyl)oxy]methyl]-1-[[2- (trimethylsilyl)ethoxy] methyl]imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]-2,4- difluorophenyl]-5-fluoro-2-methylpyridine-3-sulfonamide (140 mg, 0.16 mmol, 1 equiv) and TBAF in THF (4 mL, 1M) at room temperature. The resulting mixture was stirred overnight at 70 °C under nitrogen atmosphere. The resulting mixture was diluted with sat. NH ₄ Cl (aq.) (10 mL) and extracted with EtOAc (3 x 10 mL). The combined organics were washed with brine (5 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Flow rate 90 mL/min; Mobile phase: 5-40% MeCN / 0.05% aqueous formic acid; to afford N-(2,4-difluoro-3-[1-[4-(hydroxymethyl)-3H- imidazol-2-yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-5-fluoro-2- methylpyridine-3-sulfonamide (15 mg, 18% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 515. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.71 (d, J = 2.8 Hz, 1H), 8.51 (m, 2H), 8.21 (d, J = 9.4 Hz, 1H), 7.95 (dd, J = 8.2, 2.8 Hz, 1H), 7.34 (td, J = 8.9, 5.9 Hz, 1H), 7.21 (t, J = 9.3 Hz, 1H), 6.95 (s, 1H), 6.82 (d, J = 9.4 Hz, 1H), 4.86 (s, 1H), 4.45 (s, 2H), 2.78 (d, J = 1.2 Hz, 3H). Example 67: Synthesis of 5-chloro-N-[3-[1-(4-chloro-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide (Compound 52) Compound 52 Synthesis of 52-a: 5-chloro-N-[3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]meth yl]imidazol- 2-yl) imidazo [1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-2-methoxypyridine-3 -sulfonamide [0487] Into an 8 mL vial were added 3-[1-(4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl]-2,4-difluoroaniline (150 mg, 0.3 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (114 mg, 0.47 mmol, 1.5 equiv), DCM (2 mL) and pyridine (124 mg, 1.56 mmol, 5 equiv). The resulting mixture was stirred overnight at room temperature. The reaction mixture was concentrated under vacuum and the residue purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 5-chloro-N-[3-[1-(4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 2-methoxypyridine-3-sulfonamide (140 mg, 65% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 681. Synthesis of Compound 52: 5-chloro-N-[3-[1-(4-chloro-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide [0488] Into an 8 mL vial were added 5-chloro-N-[3-[1-(4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 2-methoxypyridine-3-sulfonamide (130 mg, 0.19 mmol, 1 equiv) and TFA (2 mL). The resulting mixture was stirred for 2 h at 60 °C, then concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column, Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase: 30-65% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; to afford 5-chloro-N-[3-[1-(4-chloro-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]-2,4-difluorophenyl]-2-methoxypyridine-3- sulfonamide (33 mg, 31% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 551. 1H NMR (300 MHz, Methanol-d ₄ ) δ 8.43 – 8.32 (m, 3H), 8.16 (d, J = 9.5 Hz, 1H), 8.10 (d, J = 2.6 Hz, 1H), 7.54 (td, J = 8.9, 5.7 Hz, 1H), 7.19-7.07 (m, 2H), 6.92 (dd, J = 9.4, 1.6 Hz, 1H), 4.03 (s, 3H). Example 68: Synthesis of 5-cyano-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 53) Synthesis of Compound 53: 5-cyano-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0489] Into an 8 mL vial was placed 2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5- a]pyridin-6-yl]aniline (80 mg, 0.25 mmol, 1 equiv), pyridine (2 mL), 5-cyano-2- methoxypyridine-3-sulfonyl chloride (172 mg, 0.7 mmol, 3 equiv) and DCM (0.1 mL). The resulting solution was stirred for 1 h at room temperature, then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 10-60% MeCN / 0.1% aqueous formic acid; to afford 5-cyano-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1 ,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (34 mg, 27% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 522 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.52 (s, 1H), 8.93 (d, J = 2.0 Hz, 1H), 8.53-8.41 (m, 3H), 8.10 (d, J = 9.4 Hz, 1H), 7.73 (d, J = 2.2 Hz, 1H), 7.37 (td, J = 8.7, 5.6 Hz, 1H), 7.22 (t, J = 9.0 Hz, 1H), 6.76 (d, J = 9.4 Hz, 1H), 6.62 (d, J = 2.1 Hz, 1H), 4.02 (s, 3H), 3.92 (s, 3H). Example 69: Synthesis of N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonami de (Compound 54) Synthesis of Compound 54: N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonami de [000362] Into an 8 mL vial was placed 2,4-difluoro-3-[1-(1-methylpyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]aniline (80 mg, 0.25 mmol, 1 equiv), pyridine (2 mL), 5- fluoro-2-methylpyridine-3-sulfonyl chloride (155 mg, 0.7 mmol, 3 equiv) and DCM (0.1 mL). The resulting solution was stirred for 1 h at room temperature and concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250 mm, 10 µm; Mobile Phase: 15-45% MeCN / 0.1% aqueous formic acid; to afford N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5-a]pyr idin-6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide (35 mg, 29% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 499 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.77 (s, 1H), 8.74 (dd, J = 2.9, 1.2 Hz, 1H), 8.45 (d, J = 3.1 Hz, 2H), 8.09 (d, J = 9.4 Hz, 1H), 8.01-7.91 (m, 1H), 7.73 (t, J = 1.7 Hz, 1H), 7.35 (td, J = 8.9, 5.8 Hz, 1H), 7.24 (t, J = 9.2 Hz, 1H), 6.72 (dd, J = 9.5, 1.7 Hz, 1H), 6.61 (t, J = 1.7 Hz, 1H), 3.92 (d, J = 1.3 Hz, 3H), 2.78 (d, J = 1.4 Hz, 3H).

Example 70: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3-triazol-1-yl)imidazo[1, 5- a]pyridin-6-yl] phenyl] -2-methoxypyridine-3-sulfonamide & 5-chloro-N-[2,4-difluoro- 3-[1-(1,2,3-triazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]- 2- methoxypyridine-3- sulfonamide (Compound 55-1 and 55-2) Synthesis of 55-a/b: 2,4-difluoro-3-[1-(1,2,3-triazol-1-yl)imidazo[1,5-a]pyridin- 6-yl]aniline & 2,4-difluoro -3-[1-(1,2,3-triazol-2-yl)imidazo[1,5-a]pyridin-6-yl]aniline [0490] A mixture of 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyridin-6-yl]aniline (100 mg, 0.27 mmol, 1 equiv), (1S,2S)-N1,N2-dimethylcyclohexane-1,2-diamine (15 mg, 0.1 mmol, 0.4 equiv), 1,2,3-triazole (37 mg, 0.54 mmol, 2 equiv), Cs ₂ CO ₃ (351 mg, 1.1 mmol, 4 equiv) and CuI (10 mg, 0.054 mmol, 0.2 equiv) in DMF (1 mL) was stirred overnight at 100 °C under nitrogen atmosphere. The mixture was allowed to cool and was diluted with water (5 mL). The resulting mixture was extracted with EtOAc (3 x 10 mL), and the combined organics were washed with water and brine, then dried over anhydrous Na ₂ SO ₄ , before being concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, Atlantis HILIC OBD, 19*150 mm*5 µm; mobile phase: 10- 42% MeCN / 0.1% aqueous formic acid; Detector, uv. This resulted in 2,4-difluoro-3-[1- (1,2,3-triazol-1-yl)imidazo[1,5-a]pyridin-6-yl]aniline (13 mg, 15% yield) as an off-white solid, and 2,4-difluoro-3-[1-(1,2,3-triazol-2-yl)imidazo[1,5-a]pyridin- 6-yl]aniline (15 mg, 18% yield) as an off-white solid . LCMS (ES, m/z): [M+H] ⁺ : 313 & [M+H] ⁺ : 313. Synthesis of Compound 55-1: 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3-triazol-1-yl)imidazo[1, 5- a]pyridin-6-yl] phenyl] -2-methoxypyridine-3-sulfonamide [0491] To a stirred solution of 2,4-difluoro-3-[1-(1,2,3-triazol-1-yl)imidazo[1,5-a]pyridin- 6- yl]aniline (13 mg, 0.04 mmol, 1 equiv) and pyridine (13 mg, 0.16 mmol, 4 equiv) in DCM (0.2 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (30 mg, 0.12 mmol, 3 equiv) dropwise at room temperature and the resulting mixture was stirred for 2 h. The reaction was diluted with water (2 mL), and was extracted with EtOAc (3 x 10 mL). The combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, Atlantis HILIC OBD, 19*150 mm*5 µm; mobile phase: 25- 60% MeCN / 0.1% aqueous formic acid; Detector, uv. This resulted in 5-chloro-N-[2,4- difluoro-3-[1-(1,2,3-triazol-1-yl)imidazo[1,5-a]pyridin-6-yl ]phenyl]-2-methoxypyridine-3- sulfonamide (2.8 mg, 13% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 518. ¹ H NMR (300 MHz, DMSO-d6) δ 10.46 (s, 1H), 8.68 (d, J = 1.2 Hz, 1H), 8.60 (d, J = 4.8 Hz, 2H), 8.50 (s, 1H), 8.09 (d, J = 2.6 Hz, 1H), 8.02-7.92 (m, 2H), 7.37 (s, 1H), 7.26 (d, J = 9.7 Hz, 1H), 6.95 (d, J = 9.9 Hz, 1H), 3.92 (s, 3H). Synthesis of Compound 55-2: 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3-triazol-2-yl)imidazo[1, 5- a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0492] To a stirred solution of 2,4-difluoro-3-[1-(1,2,3-triazol-2-yl)imidazo[1,5-a]pyridin- 6- yl]aniline (15 mg, 0.045 mmol, 1 equiv) and pyridine (15 mg, 0.18 mmol, 4 equiv) in DCM (0.1 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (11 mg, 0.05 mmol, 1.5 equiv) dropwise at room temperature. The resulting mixture was stirred for 2 h, then was diluted with water (2 mL). The resulting mixture was extracted with EtOAc (3 x 10 mL) and the combined organics were washed with water and brine, then dried over anhydrous Na ₂ SO ₄ , before being concentrated under reduced pressure. The crude product was purified by Prep- HPLC with the following conditions: Column, Atlantis HILIC OBD, 19*150 mm*5 µm; mobile phase: 30-70% MeCN / 0.1% aqueous formic acid; Detector, uv. This resulted in 5- chloro-N-[2,4-difluoro-3-[1-(1,2,3-triazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (9.1 mg, 55% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 518. ¹ H-NMR (300 MHz, DMSO-d6) δ 10.46 (s, 1H), 8.59 (s, 1H), 8.55-8.47 (m, 2H), 8.13 (s, 2H), 8.10 (d, J = 2.6 Hz, 1H), 7.96 (d, J = 9.5 Hz, 1H), 7.46-7.34 (m, 1H), 7.28 (dd, J = 9.1, 1.5 Hz, 1H), 6.91 (dd, J = 9.6, 1.6 Hz, 1H), 3.93 (s, 3H). Example 71: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2- yl)imidazo[1,5-a]pyridine -6-yl]phenyl]-2-methylpyridine-3-sulfonamide (Compound 56) Compound 56 Synthesis of 56-a: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide [0493] To a stirred solution of 2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (200 mg, 0.44 mmol, 1 equiv) and pyridine (139 mg, 1.76 mmol, 4 equiv) in DCM (2 mL) was added 5-chloro-2-methylpyridine-3-sulfonyl chloride (200 mg, 0.88 mmol, 2 equiv) in portions, and the reaction stirred for 4 h at room temperature. Water (2 mL) was added and the resulting mixture was extracted with CH ₂ Cl ₂ (3 x 10 mL). The combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE(0-50%) to afford 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-1-[[2-(trimethylsily l)ethoxy]methyl]imidazol- 2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-s ulfonamide (190 mg, 67% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 645. Synthesis of Compound 56: 5-chloro-N-[2,4-difluoro-3-[1-(4-methyl-3H-imidazol-2- yl)imidazo[1,5-a]pyridine -6-yl]phenyl]-2-methylpyridine-3-sulfonamide [0494] To a stirred mixture of 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (160 mg, 0.25 mmol, 1 equiv) was added DCM (2 mL) and TFA (1 mL). The resulting mixture was stirred for 30 min at 40 °C, then concentrated under vacuum. The residue was neutralized to pH 7 with ammonia, and was purified by Prep- HPLC: Column, Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase: 10-50% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; to afford 5-chloro-N-[2,4-difluoro-3-[1-(4- methyl-3H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2 -methylpyridine-3- sulfonamide (11 mg, 9% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 515. ¹ H NMR (300 MHz, DMSO-d ₆ ): 11.91 (br, 1H), 8.73 (d, J = 2.4 Hz, 1H), 8.52 (d, J = 5.0 Hz, 2H), 8.25-8.11 (m, 1H), 8.08 (d, J = 2.4 Hz, 1H), 7.37-7.32 (m, 1H), 7.20 (td, J = 9.2, 1.6 Hz, 1H), 6.89-6.80 (m, 2H), 2.77 (s, 3H), 2.23 (s, 3H).

Example 72: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 57) Compound 57 Synthesis of 57-a: 3-methyl-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazole [0495] To a solution of 3-methyl-4H-1,2,4-triazole (3 g, 36 mmol, 1 equiv) in DMF (180 mL) was added NaH (2.9 g, 72 mmol, 2 equiv, 60% in oil) in portions at 0 °C. The resulting mixture was stirred for 0.5 h at 0 °C, then SEM-Cl (7.2 g, 43.32 mmol, 1.2 equiv) was added dropwise at 0 °C. The resulting solution was stirred for 2 h at room temperature, then quenched with 100 mL of water. The resulting solution was extracted with 3 x 100 mL of ethyl acetate and the organics dried over anhydrous sodium sulfate, before being concentrated under vacuum. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:1). This resulted in 3-methyl-4-[[2-(trimethylsilyl)ethoxy]methyl]- 1,2,4-triazole (3 g, 39% yield) as an off-white liquid. LCMS (ES, m/z): [M+H] ⁺ : 214 Synthesis of 57-b: 2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy]met hyl]-1,2,4- triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]aniline [0496] Into a 100 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 3-methyl-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4- triazole (1.2 g, 5.7 mmol, 3 equiv) in THF (35 mL) and the mixture was cooled to -78 °C. 2.5M n-BuLi in hexanes (2.5 mL, 6.2 mmol, 3.3 equiv) was added dropwise at -78 °C for 5 min, and the resulting solution was stirred for 30 min at -78 °C. ZnCl ₂ (1 M in Et ₂ O, 6.2 mL, 6.2 mmol, 3.3 equiv) was added at low temperature, then the mixture was warmed to room temperature for 30 min. A solution of Pd(PPh ₃ ) ₄ (0.22 g, 0.19 mmol, 0.1 equiv) in THF (1 mL) and a solution of 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyridin-6-yl]aniline (0.7 g, 1.88 mmol, 1 equiv) in THF (2 mL) were added. The resulting solution was heated to 60 °C overnight. The reaction was cooled and quenched by the addition of 100 mL of water. The solids were removed by filtration, and the filtrate extracted with 3 x 50 mL of ethyl acetate. The combined organics were washed with 100 ml of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 10-70% MeCN/0.1% formic acid; Detector, 220 nm; to give 2,4-difluoro-3-[1- (5-methyl-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazol -3-yl)imidazo[1,5-a]pyridin-6- yl]aniline (0.65 g, 75 % yield) as a light brown semi-solid. LCMS (ES, m/z): [M+H] ⁺ : 457 Synthesis of 57-c: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0497] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]aniline (100 mg, 0.22 mmol, 1 equiv), pyridine (3 mL) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (80 mg, 0.33 mmol, 1.5 equiv). The resulting solution was stirred overnight at room temperature, then concentrated under reduced pressure. The residue was purified by Flash- Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820- 40 μm, 120 g; mobile phase; 10-85% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to yield 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsily l)ethoxy]methyl]-1,2,4- triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyr idine-3-sulfonamide (86 mg, 59% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 662 Synthesis of Compound 57: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0498] Into a 40 mL vial was placed 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (85 mg, 0.13 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 5 h at room temperature, then concentrated under vacuum. The pH was adjusted to 8 with NH ₃ (7 mol/L in MeOH, 3 mL) and the crude product was purified by Prep-HPLC using the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 15-55% MeCN/ 0.1% aqueous formic acid; Detector, 220 nm; to give 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (48 mg, 70% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 532 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 14.00-13.54 (m, 1H), 10.46 (s, 1H), 8.70-8.44 (m, 3H), 8.21 (d, J = 9.4 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.42-7.31 (m, 1H), 7.25 (t, J = 9.1 Hz, 1H), 7.04-6.78 (m, 1H), 3.93 (s, 3H), 2.38 (m, 3H). Example 73: Synthesis of N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide (Compound 58) Compound 58 Synthesis of 58-a: N-[2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy] methyl]-1,2,4- triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-m ethoxypyridine-3-sulfonamide [0499] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]aniline (100 mg, 0.22 mmol, 1 equiv), pyridine (4 mL) and 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (74 mg, 0.33 mmol, 1.5 equiv). The resulting solution was stirred overnight at 25 °C and concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-90% MeCN/0.1% aqueous formic acid; Detector, 220 nm; to give N-[2,4-difluoro-3- [1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-tria zol-3-yl)imidazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (80 mg, 57% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 646 Synthesis of Compound 58: N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide [0500] Into a 40 mL vial was placed N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl] -1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide (80 mg, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 5 h at room temperature, then concentrated under vacuum. The pH was adjusted to 8 with NH ₃ (7 mol/L in MeOH, 3 mL) and the crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 13-48% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to yield N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl)imidazo [1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide (23 mg, 35% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 516 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.92-13.50 (d, 1H), 10.45 (s, 1H), 8.60 (s, 1H), 8.56-8.44 (m, 2H), 8.21 (d, J = 9.4 Hz, 1H), 8.03 (dd, J = 7.3, 3.0 Hz, 1H), 7.37 (q, J = 7.9, 7.3 Hz, 1H), 7.25 (t, J = 9.1 Hz, 1H), 7.02-6.77 (m, 1H), 3.92 (s, 3H), 2.43-2.33 (m, 3H). Example 74: Synthesis of 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 59) Synthesis of 59-a: 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0501] Into a 40 mL vial, was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]aniline (100 mg, 0.22 mmol, 1 equiv), pyridine (4 mL) and 5-cyano-2-methoxypyridine-3-sulfonyl chloride (76 mg, 0.33 mmol, 1.5 equiv). The resulting solution was stirred overnight at room temperature. The reaction mixture was concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase, 10-90% MeCN / 0.1% aqueous formic acid over 15 mins; Detector, 220 nm. This resulted in 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4- [[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidaz o[1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (95 mg, 66%) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 653 Synthesis of Compound 59: 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0502] Into a 40 mL vial, was placed 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (90 mg, 0.14 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 5 h at room temperature. The resulting mixture was concentrated under vacuum. The pH value of the solution was adjusted to 8 with NH ₃ (7 mol/L in MeOH, 3 mL). The crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250 mm, 10 µm mobile phase; Mobile Phase, 10-47% MeCN / 0.1% aqueous formic acid over 15 mins; Detector, 220 nm. This resulted in 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl )imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide(21 mg, 29%) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 523 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.95-13.50 (m, 1H), 10.45 (s, 1H), 8.91 (d, J = 2.2 Hz, 1H), 8.59 (s, 1H), 8.48 (d, J = 2.2 Hz, 2H), 8.25-8.11 (m, 1H), 7.36 (td, J = 8.9, 5.9 Hz, 1H), 7.20 (t, J = 9.1 Hz, 1H), 7.03-6.75 (m, 1H), 4.01 (s, 3H), 2.42-2.33 (m, 3H). Example 75: Synthesis of : N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyrid ine-3-sulfonamide (Compound 60) Compound 60 Synthesis of 60-a: N-[2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy] methyl]-1,2,4- triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-m ethylpyridine-3-sulfonamide [0503] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]aniline (400 mg, 0.88 mmol, 1 equiv), pyridine (10 mL) and 5-fluoro-2-methylpyridine-3-sulfonyl chloride (367 mg, 1.8 mmol, 2 equiv). The resulting solution was stirred overnight at 25 °C. Concentration gave the crude product which was purified by Flash-Prep-HPLC using the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 10-89% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give N-[2,4- difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy]methyl] -1,2,4-triazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonami de (370 mg, 67% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 630 Synthesis of Compound 60: N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyrid ine-3-sulfonamide [0504] Into a 40 mL vial was placed N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-5- fluoro-2-methylpyridine-3-sulfonamide (360 mg, 1 equiv), DCM (10 mL) and TFA (3 mL). The resulting solution was stirred for 5 h at 25 °C and concentrated under vacuum. The pH as adjusted to 8 with NH ₃ (7 mol/L in MeOH, 2 mL) and the crude product purified by Prep- HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 5-37% MeCN / 0.05% aqueous NH ₃ ; Detector, 220 nm; to give N-[2,4- difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl)imidazo[1,5-a] pyridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide (150 mg, 53% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 500 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.95-13.55 (m, 1H), 10.79 (br s, 1H), 8.74 (d, J = 2.8 Hz, 1H), 8.69-8.41 (m, 2H), 8.20 (d, J = 9.4 Hz, 1H), 7.96 (dd, J = 8.2, 2.9 Hz, 1H), 7.46-7.21 (m, 2H), 7.04- 6.71 (m, 1H), 2.78 (d, J = 1.2 Hz, 3H), 2.50 (s, 3H).

Example 76: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sul fonamide (Compound 61) Compound 61 Synthesis of 61-a: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide [0505] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl) imidazo[1,5-a]pyridin-6-yl]aniline (100 mg, 0.22 mmol, 1 equiv), pyridine (3 mL) and 5-chloro-2-methylpyridine-3-sulfonyl chloride (99 mg, 0.44 mmol, 2 equiv). The resulting solution was stirred overnight at 25 °C, then concentrated under reduced pressure to afford 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl- 4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imid azo[1,5-a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (93 mg, 66% yield) as a white solid which was used in the next step without further purification. LCMS (ES, m/z): [M+H] ⁺ : 646 Synthesis of Compound 61: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sul fonamide [0506] Into a 40 mL vial was placed 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (90 mg, 0.13 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL, 13 mmol). The resulting solution was stirred for 5 h at 25 °C, then concentrated under vacuum. The pH was adjusted to 8 with NH ₃ (7 mol/L in MeOH, 3 mL) and the crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase, 10-50% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sul fonamide (37 mg, 51% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 516 1H NMR (300 MHz, DMSO-d ₆ ) δ 14.01-13.44 (m, 1H), 10.79 (s, 1H), 8.78 (d, J = 2.4 Hz, 1H), 8.63-8.43 (m, 2H), 8.20 (d, J = 9.4 Hz, 1H), 8.08 (d, J = 2.4 Hz, 1H), 7.44-7.19 (m, 2H), 6.98-6.75 (m, 1H), 2.77 (s, 3H), 2.38 (s, 3H). Example 77: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide (Compound 62) Synthesis of Compound 62: 5-chloro-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide [0507] Into an 8 mL vial was placed 2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo[1,5- a]pyridin-6-yl]aniline (80 mg, 0.25 mmol, 1 equiv), pyridine (2 mL) and 5-chloro-2- methylpyridine-3-sulfonyl chloride (167 mg, 0.7 mmol, 3 equiv) at room temperature. The resulting solution was stirred for 1 h then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase 15-45% MeCN / 0.1% aqueous formic acid; to afford 5- chloro-N-[2,4-difluoro-3-[1-(1-methylpyrazol-3-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (20 mg, 16% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 515 1H NMR (300 MHz, DMSO-d ₆ ) δ 8.67 (s, 1H), 8.43 (s,2H), 8.13-8.04 (m, 2H), 7.72 (d, J = 2.2 Hz, 1H), 7.27 (q, 1H), 7.13 (t, 1H), 6.75 (d, J = 9.4 Hz, 1H), 6.61 (d, J = 2.2 Hz, 1H), 3.92 (s, 3H), 2.77 (s, 3H). Example 78: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1- yl)imidazo[1,5-a]pyridin-6-yl]phenyl] -2-methoxypyridine-3-sulfonamide (Compound 63) Synthesis of 63-a: N-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1,1-diphenylmethanimin e [0508] A mixture of phenyl-benzenemethanimine (1.8 g, 9.9 mmol, 0.8 equiv), 6-bromo-1- iodoimidazo[1,5-a]pyridine (4 g, 12 mmol, 1 equiv), Pd ₂ (dba) ₃ (1.13 g, 1.2 mmol, 0.1 equiv), XantPhos (1.43 g, 2.5 mmol, 0.2 equiv) and t-BuONa (3.57 g, 37 mmol, 3 equiv) in toluene (80 mL) was stirred for 1 h at 60 °C under nitrogen atmosphere. The mixture was allowed to cool to room temperature and was diluted with water (100 mL). This was extracted with EtOAc (3 x 100 mL) and the combined organic layers were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-50%) to afford N- [6-bromoimidazo[1,5-a]pyridin-1-yl]-1,1-diphenylmethanimine (5 g, 86% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 376, 378 Synthesis of 63-b: 6-bromoimidazo[1,5-a]pyridin-1-amine hydrochloride [0509] To a stirred mixture of N-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1,1- diphenylmethanimine (800 mg, 2.1 mmol, 1 equiv) were added HCl in 1,4-dioxane (8 mL, 32 mmol, 15 equiv, 4 M) dropwise at 0 °C. The resulting mixture was stirred for 1 h at room temperature, then concentrated under reduced pressure. The residue was purified by trituration with PE/EA (1:1). The solid was removed by filtration and dried to give 6- bromoimidazo[1,5-a]pyridin-1-amine hydrochloride (500 mg, 95% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 212, 214 Synthesis of 63-c: 1-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1,2,3,4-tetrazole [0510] A solution of 6-bromoimidazo[1,5-a]pyridin-1-amine (1 g, 4.8 mmol, 1 equiv), triethyl orthoformate (1.75 g, 12 mmol, 2.5 equiv) and sodium azide (770 mg, 12 mmol, 2.5 equiv) in CH ₃ COOH (10 mL) was stirred overnight at 90 °C under nitrogen atmosphere. The mixture was allowed to cool and was concentrated under reduced pressure. The resulting mixture was diluted with water (10 mL), then extracted with EtOAc (3 x 30 mL). The combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-100%) to afford 1-[6-bromoimidazo[1,5- a]pyridin-1-yl]-1,2,3,4-tetrazole (520 mg, 42% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 265, 266 Synthesis of 63-d: 2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5-a]pyrid in-6-yl]aniline [0511] A solution of 1-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1,2,3,4-tetrazole (520 mg, 2 mmol, 1 equiv), 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) aniline (750 mg, 3 mmol, 1.5 equiv), Pd(dtbpf)Cl ₂ (128 mg, 0.2 mmol, 0.1 equiv) and K ₂ CO ₃ (813 mg, 5.9 mmol, 3 equiv) in dioxane (4.5 mL) and H ₂ O (0.5 mL) was stirred overnight at 80 °C under nitrogen atmosphere. The mixture was allowed to cool to room temperature and was diluted with water (10 mL). The resulting mixture was extracted with EtOAc (3 x 30 mL), and the combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-100%) to afford 2,4-difluoro-3-[1-(1,2,3,4- tetrazol-1-yl)imidazo[1,5-a]pyridin-6-yl]aniline (400 mg, 65% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 314 Synthesis of Compound 63: 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo [1,5- a]pyridin-6-yl]phenyl] -2-methoxypyridine-3-sulfonamide [0512] To a stirred solution of 2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5-a]pyrid in- 6-yl]aniline (50 mg, 0.16 mmol, 1 equiv) and pyridine (50 mg, 0.64 mmol, 4 equiv) in DCM (0.5 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (58 mg, 0.24 mmol, 1.5 equiv) dropwise at room temperature. The resulting mixture was stirred for 2 h, then diluted with water (5 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL), and the combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, Sunfire Prep C18 OBD, 50*250 mm 5 µm 10 nm; mobile phase: 25-60% MeCN/0.1% aqueous formic acid; Detector, uv; to give 5-chloro-N-[2,4- difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5-a]pyridin-6 -yl]phenyl]-2-methoxypyridine-3- sulfonamide (17mg, 20% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 519. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.48 (s, 1H), 10.05 (s, 1H), 8.66 (m, 2H), 8.50 (d, J = 2.6 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.91 (d, J = 9.5 Hz, 1H), 7.39 (td, J = 8.9, 5.9 Hz, 1H), 7.31-7.19 (m, 1H), 7.03 (dd, J = 9.5, 1.5 Hz, 1H), 3.92 (s, 3H).

Example 79: Synthesis of (R)-N-(3-(3-(1H-imidazol-2-yl)-5,6,7,8-tetrahydroimidazo[1,5 - a]pyridin-7-yl)-2,4-difluorophenyl)-5-chloro-2-methoxypyridi ne-3-sulfonamide & (S)-N- (3-(3-(1H-imidazol-2-yl)-5,6,7,8-tetrahydroimidazo[1,5-a]pyr idin-7-yl)-2,4- difluorophenyl)-5-chloro-2-methoxypyridine-3-sulfonamide (Compounds 64-1 & 64-2) Synthesis of 64-a: 2,4-difluoro-3-[3-(1-[[2-(trimethylsilyl)ethoxy]methyl]imida zol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-7-yl]aniline [0513] To a stirred solution of 2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-7-yl]aniline (500 mg, 1.1 mmol, 1 equiv) in EtOH (20 mL) was added Pd/C (120 mg, 10%). The resulting mixture was hydrogenated under 20 atm of hydrogen for 6 h at 80 °C. After cooling, the mixture was filtered through celite and the filtrate concentrated under reduced pressure. The residue was purified by column chromatography over silica gel (eluent: PE:EA = 1:1) to afford 2,4- difluoro-3-[3-(1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol- 2-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-7-yl]aniline (480 mg, 95% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 446 Synthesis of 64-b: 5-chloro-N-[2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-7- yl]phenyl]-2-methoxypyridine-3-sulfonamide [0514] To a stirred solution of 2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-7- yl]aniline (480 mg, 1 mmol, 1 equiv) and pyridine (255 mg, 3.2 mmol, 3 equiv) in DCM (10 mL) were added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (391 mg, 1.6 mmol, 1.5 equiv) in portions at room temperature. The resulting solution was stirred for 3 h then concentrated under pressure. The residue was purified by column chromatography over silica gel (eluent: PE:EA = 5:1) to afford 5-chloro-N-[2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-7- yl]phenyl]-2-methoxypyridine-3-sulfonamide (470 mg, 67% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 651 Synthesis of Compounds 64-1 & 64-2: Assumed (R)-N-(3-(3-(1H-imidazol-2-yl)-5,6,7,8- tetrahydroimidazo[1,5-a]pyridin-7-yl)-2,4-difluorophenyl)-5- chloro-2-methoxypyridine-3- sulfonamide and Assumed (S)-N-(3-(3-(1H-imidazol-2-yl)-5,6,7,8-tetrahydroimidazo[1,5 - a]pyridin-7-yl)-2,4-difluorophenyl)-5-chloro-2-methoxypyridi ne-3-sulfonamide [0515] To a stirred solution of 5-chloro-N-[2,4-difluoro-3-[3-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-7- yl]phenyl]-2-methoxypyridine-3-sulfonamide (450 mg, 0.7 mmol, 1 equiv) in DCM (5 mL) was added TFA (1 mL) dropwise at room temperature. The resulting mixture was stirred for 1 h at room temperature, then concentrated under reduced pressure. The residue was purified by prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 30-50% MeCN/0.1% aqueous formic acid; Detector, 220 nm; and chiral prep-HPLC with the following conditions: Column, YMC, SC, 250 x 30 mm, 5 µm; Mobile Phase 50% EtOH/Hexane; to afford (R)-N-(3-(3-(1H-imidazol-2-yl)-5,6,7,8- tetrahydroimidazo[1,5-a]pyridin-7-yl)-2,4-difluorophenyl)-5- chloro-2-methoxypyridine-3- sulfonamide (70 mg, 19% yield, stereochemistry assumed, RT=10 min) as a white solid and (S)-N-(3-(3-(1H-imidazol-2-yl)-5,6,7,8-tetrahydroimidazo[1,5 -a]pyridin-7-yl)-2,4- difluorophenyl)-5-chloro-2-methoxypyridine-3-sulfonamide (80 mg, 22% yield, stereochemistry assumed, RT=12 min) as a white solid. Assumed-(R)-N-(3-(3-(1H-imidazol-2-yl)-5,6,7,8-tetrahydroimi dazo[1,5-a]pyridin-7-yl)-2,4- difluorophenyl)-5-chloro-2-methoxypyridine-3-sulfonamide LCMS (ES, m/z): [M+H] ⁺ : 521 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.57 (s, 1H), 10.29 (s, 1H), 8.50 (d, J = 2.6 Hz, 1H), 8.00 (d, J = 2.5 Hz, 1H), 7.31-6.95 (m, 4H), 6.77 (s, 1H), 5.10-4.89 (m, 1H), 4.10 (td, J = 12.9, 4.5 Hz, 1H), 3.93 (s, 3H), 3.47-3.35 (m, 1H), 3.06- 2.74 (m, 2H), 2.33-2.23 (m, 1H), 2.07 (d, J = 13.3 Hz, 1H). Assumed-(S)-N-(3-(3-(1H-imidazol-2-yl)-5,6,7,8-tetrahydroimi dazo[1,5-a]pyridin-7-yl)-2,4- difluorophenyl)-5-chloro-2-methoxypyridine-3-sulfonamide LCMS (ES, m/z): [M+H] ⁺ : 521 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.56 (s, 1H), 10.29 (s, 1H), 8.51 (d, J = 2.6 Hz, 1H), 8.00 (d, J = 2.6 Hz, 1H), 7.30-6.95 (m, 4H), 6.77 (s, 1H), 4.97 (d, J = 14.3 Hz, 1H), 4.10 (t, J = 11.1 Hz, 1H), 3.93 (s, 3H), 3.39 (s, 1H), 3.07-2.77 (m, 2H), 2.27 (q, J = 1.9 Hz, 1H), 2.07 (d, J = 12.8 Hz, 1H). Example 80: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl] -2-methylpyridine-3-sulfonamide (Compound 65) Compound 65 Synthesis of 65-a: 1-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazole [0516] Into a 100 mL 3-necked round-bottom flask were added 1,2,4-triazole (2 g, 29 mmol, 1 equiv) and DMF (20 mL). To the above mixture was added NaH (2.1 g, 88 mmol, 3 equiv) in portions at 0 °C. The resulting mixture was stirred for 30 min at 0 °C and [2- (chloromethoxy)ethyl]trimethylsilane (5.3 g, 32 mmol, 1.1 equiv) was added dropwise. The resulting mixture was stirred for 1 h at 0 °C, then quenched with water (100 mL). The resulting mixture was diluted further with water (100 mL) and extracted with EtOAc (3 x 100 mL). The combined organic layers were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:1) to afford 1-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazole (1.5 g, 26% yield) as a colorless oil. LCMS (ES, m/z): [M+H] ⁺ : 200. Synthesis of 65-b: 2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2, 4-triazol-3- yl)imidazo [1,5-a]pyridin-6-yl]aniline [0517] Into a 100 mL 3-necked round-bottom flask was added 4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazole (900 mg, 4.5 mmol, 1 equiv) in THF (20 mL). To this was added 2.5M n-BuLi (2.7 mL, 6.7 mmol, 1.5 equiv) dropwise at -78 °C. The resulting mixture was stirred for 1 h at -78 °C, then 1M ZnCl ₂ in Et ₂ O (4.5 mL, 4.5 mmol, 1 equiv) was added. The resulting mixture was stirred from -78 °C to room temperature over 1 hr, then 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyridin-6-yl]aniline (552 mg, 1.5 mmol, 0.33 equiv) and Pd(PPh ₃ ) ₄ (521 mg, 0.45 mmol, 0.1 equiv) were added. The reaction was stirred for 1 h at 60 °C, then cooled and diluted with water (100 mL). This mixture was extracted with EtOAc (3 x 100 mL), and the combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (3:2) to afford 2,4- difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-tr iazol-3-yl)imidazo[1,5-a]pyridin- 6-yl]aniline (700 mg, 30% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 443 Synthesis of 65-c: 5-chloro-N-[2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy] methyl]-1,2,4- triazol-3-yl) imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfon amide [0518] Into an 8 mL vial were added 2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]methyl]- 1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]aniline (150 mg, 0.3 mmol, 1 equiv), 5-chloro- 2-methylpyridine-3-sulfonyl chloride (114 mg, 0.5 mmol, 1.5 equiv), DCM (5 mL) and pyridine (134 mg, 1.7 mmol, 5 equiv). The resulting mixture was stirred overnight at room temperature, then concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 5-chloro-N-[2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (130 mg, 61% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 632. Synthesis of Compound 65: 5-chloro-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl] -2-methylpyridine-3-sulfonamide [0519] Into an 8 mL vial were added 5-chloro-N-[2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (107 mg, 0.17 mmol, 1 equiv) and TFA (2 mL). The resulting mixture was stirred for 30 min at 60 °C, then was concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm* 5 µm; Mobile Phase: 20-50% MeCN/0.1% aqueous formic acid; Flow rate: 90 mL/min; Detector 220 nm; to afford 5-chloro-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol- 3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-s ulfonamide (22 mg, 25% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 502. ¹ H NMR (300 MHz, Methanol-d ₄ ) δ 8.65 (d, J = 2.4 Hz, 1H), 8.47 (s, 1H), 8.43 (d, J = 1.4 Hz, 1H), 8.30 (s, 1H), 8.22 (d, J = 9.5 Hz, 1H), 8.16 (d, J = 2.4 Hz, 1H), 7.54 (td, J = 8.9, 5.7 Hz, 1H), 7.17 (td, J = 9.2, 1.9 Hz, 1H), 6.95 (dd, J = 9.4, 1.5 Hz, 1H), 2.84 (s, 3H).

Example 81: Synthesis of N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl] - 2,4-difluorophenyl] -5-cyano-2-methoxypyridine-3-sulfonamide (Compound 66) Compound 66 Synthesis of 66-a: N-(2-aminophenyl)-6-bromoimidazo[1,5-a]pyridine-1-carboxamid e [0520] Into a 100 mL round-bottom flask were added 6-bromoimidazo[1,5-a]pyridine-1- carboxylic acid (1 g, 4.2 mmol, 1 equiv) and DMF (30 mL). To the stirred solution was added HATU (2.4 g, 6.2 mmol, 1.5 equiv) and DIEA (1.07 g, 8.3 mmol, 2 equiv). The resulting mixture was stirred for 10 min when o-phenylenediamine (0.54 g, 5 mmol, 1.2 equiv) was added. The resulting mixture was stirred overnight at room temperature, then was diluted with water (100 mL). The precipitated solids were collected by filtration and washed with water (3 x 10 mL) to afford N-(2-aminophenyl)-6-bromoimidazo[1,5-a]pyridine-1- carboxamide (900 mg, 66% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ :331, 333. Synthesis of 66-b: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1H-1,3-benzodiazole [0521] Into a 20 mL vial were added N-(2-aminophenyl)-6-bromoimidazo[1,5-a]pyridine-1- carboxamide (800 mg, 2.4 mmol, 1 equiv) and AcOH (8 mL). The resulting mixture was stirred for 1 h at 105 ^o C, then was cooled and concentrated under reduced pressure. The mixture was basified to pH 8 with saturated NaHCO ₃ (aq.) and extracted with EtOAc (3 x 30 mL). The combined organics were washed with brine (30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 2-[6-bromoimidazo[1,5-a]pyridin-1- yl]-1H-1,3-benzodiazole (720 mg, 95% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ :313, 315 Synthesis of 66-c: 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1-[[2-(trimethylsilyl) ethoxy] methyl]-1,3-benzodiazole [0522] Into a 100 mL 3-necked round-bottom flask were added 2-[6-bromoimidazo[1,5- a]pyridin-1-yl]-1H-1,3-benzodiazole (660 mg, 2.1 mmol, 1 equiv) and DMF(15 mL). To the stirred solution was added 60% NaH in oil (65 mg, 2.7 mmol, 1.3 equiv) at 0-5 °C and this mixture was stirred for 10 min at room temperature. SEM-Cl (456 mg, 2.74 mmol, 1.3 equiv) was added dropwise, and the reaction was stirred for an additional 30 min at room temperature, before being quenched with water/ice (60 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL), and the combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (5:1) to afford 2- [6-bromoimidazo[1,5-a]pyridin-1-yl]-1-[[2-(trimethylsilyl)et hoxy] methyl]-1,3-benzodiazole (750 mg, 80% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ :443, 445 Synthesis of 66-d: 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]-1,3- benzodiazol-2- yl)imidazo [1,5-a]pyridin-6-yl]aniline [0523] Into a 20 mL vial were added 2-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]-1,3-benzodiazole (700 mg, 1.6 mmol, 1 equiv), dioxane (14 mL) and H ₂ O (1.4 mL). To the stirred solution were added 2,4-difluoro-3-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (604 mg, 2.4 mmol, 1.5 equiv), K ₂ CO ₃ (654 mg, 4.7 mmol, 3 equiv) and Pd(dtbpf)Cl ₂ (103 mg, 0.16 mmol, 0.1 equiv). The reaction was stirred for 1 h at 80 °C, then cooled and diluted with water (30 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL), and the combined organic layers were washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (3:1) to afford 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]-1,3- benzodiazol-2- yl)imidazo[1,5-a]pyridin-6-yl]aniline (500 mg, 64% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 492. Synthesis of 66-e: 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]m ethyl] -1,3- benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methox ypyridine-3-sulfonamide [0524] Into a 20 mL vial were added 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]- 1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]aniline (130 mg, 0.26 mmol, 1 equiv) and DCM (4 mL). To this stirred solution were added pyridine (104 mg, 1.3 mmol, 5 equiv) and 5-cyano-2-methoxypyridine-3-sulfonyl chloride (92 mg, 0.39 mmol, 1.5 equiv) and the reaction was stirred for 1 h. The resulting mixture was concentrated under reduced pressure and the residue purified by silica gel column chromatography, eluting with PE/THF (5:1) to afford 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]m ethyl]-1,3-benzodiazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (150 mg, 77% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ :688. Synthesis of Compound 66: of N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridin-6- yl]-2,4-difluorophenyl] -5-cyano-2-methoxypyridine-3-sulfonamide [0525] Into a 2 mL vial were added 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]-1,3-benzodiazo l-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (130 mg, 0.19 mmol, 1 equiv) and TFA (2 mL). The resulting mixture was stirred for 30 min at 55 ^o C under nitrogen atmosphere, then concentrated under reduced pressure. The mixture was basified to pH 8 with ammonia, and the crude product was purified by Prep-HPLC using the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Flowrate: 90 mL/min, Mobile Phase: 16-51% MeCN / 0.05% aqueous ammonia; to afford N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5- a]pyridin-6-yl]-2,4-difluorophenyl]-5-cyano-2-methoxypyridin e -3-sulfonamide (50 mg, 48% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 558. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.74 (s, 1H), 10.56 (s, 1H), 8.94 (d, J = 2.2 Hz, 1H), 8.65 (d, J = 3.6 Hz, 2H), 8.54-8.41 (m, 2H), 7.62 (s, 1H), 7.47 (s, 1H), 7.40 (td, J = 8.9, 5.9 Hz, 1H), 7.32-7.21 (m, 1H), 7.21-7.10 (m, 2H), 7.03 (d, J = 9.6 Hz, 1H), 4.03 (s, 3H). Example 82: Synthesis of (R)-6-(2,6-difluoro-3-((5-fluoro-2-methoxypyridine)-3- sulfonamido)phenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a ]pyridine-1- carboxamide and (S)-6-(2,6-difluoro-3-((5-fluoro-2-methoxypyridine)-3- sulfonamido)phenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a ]pyridine-1- carboxamide (Compounds 67-1 & 67-2) Synthesis of Compounds 67-1 & 67-2: (R)-6-(2,6-difluoro-3-((5-fluoro-2-methoxypyridine)- 3-sulfonamido)phenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5 -a]pyridine-1-carboxamide and (S)-6-(2,6-difluoro-3-((5-fluoro-2-methoxypyridine)-3-sulfon amido)phenyl)-N-methyl- 5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamide [0526] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (200 mg, 0.65 mmol, 1 equiv) in pyridine (5 mL) were added a solution of 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (221 mg, 0.98 mmol, 1.5 equiv) in DCM (1 mL) dropwise at room temperature. The solution was stirred for 1 h at room temperature, then quenched with water (20 mL). The resulting mixture was extracted with EA (3 x 20 mL), and the combined organics were washed with brine (2 x 10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase 20-50% MeCN / 0.1% aqueous formic acid; and chiral- prep-HPLC with the following conditions: Column, CHIRALPAK SB, 250*30 mm, 5 μm, Mobile Phase 10% EtOH / Hexane: DCM (5:1); to afford (6R)-6-[2,6-difluoro-3-(5-fluoro-2- methoxypyridine-3-sulfonamido)phenyl]-N-methyl-5H,6H,7H,8H-i midazo[1,5-a]pyridine-1- carboxamide (65 mg, 20% yield, stereochemistry assumed) as a white solid and (6S)-6-[2,6- difluoro-3-(5-fluoro-2-methoxypyridine-3-sulfonamido)phenyl] -N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (59 mg, 18% yield, stereochemistry assumed) as a white solid. Assumed-(R)-6-(2,6-difluoro-3-((5-fluoro-2-methoxypyridine)- 3-sulfonamido)phenyl)-N- methyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamid e LCMS (ES, m/z): [M+H] ⁺ : 496 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.30 (s, 1H), 8.48 (d, J = 3.0 Hz, 1H), 7.97 (dd, J = 7.4, 3.0 Hz, 1H), 7.74 (d, J = 5.0 Hz, 1H), 7.54 (s, 1H), 7.32-7.18 (m, 1H), 7.09 (t, J = 9.5 Hz, 1H), 4.26 (dd, J = 12.4, 5.3 Hz, 1H), 4.04-3.91 (m, 1H), 3.91 (s, 3H), 3.49 (s, 1H), 2.87 (ddd, J = 17.3, 11.6, 6.2 Hz, 1H), 2.71 (d, J = 4.8 Hz, 3H), 2.07 (s, 1H), 1.96 (s, 1H). Assumed-(S)-6-(2,6-difluoro-3-((5-fluoro-2-methoxypyridine)- 3-sulfonamido)phenyl)-N- methyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamid e LCMS (ES, m/z): [M+H] ⁺ : 496 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.30 (s, 1H), 8.47 (d, J = 3.0 Hz, 1H), 7.97 (dd, J = 7.3, 3.0 Hz, 1H), 7.74 (d, J = 5.0 Hz, 1H), 7.54 (s, 1H), 7.25 (td, J = 8.8, 5.7 Hz, 1H), 7.09 (t, J = 9.7 Hz, 1H), 4.26 (dd, J = 12.2, 5.2 Hz, 1H), 4.04 -3.91 (m, 1H), 3.91 (s, 3H), 3.48 (s, 1H), 2.87 (ddd, J = 18.1, 11.8, 6.5 Hz, 1H), 2.75-2.67 (m, 3H), 2.05 (s, 1H), 1.96 (s, 1H).

Example 83: Synthesis of (R)-6-(3-((5-cyano-2-methoxypyridine)-3-sulfonamido)-2,6- difluorophenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyr idine-1-carboxamide and (S)-6-(3-((5-cyano-2-methoxypyridine)-3-sulfonamido)-2,6-dif luorophenyl)-N-methyl- 5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamide (Compounds 68-1 & 68-2) Synthesis of Compounds 68-1 & 68-2: (R)-6-(3-((5-cyano-2-methoxypyridine)-3- sulfonamido)-2,6-difluorophenyl)-N-methyl-5,6,7,8-tetrahydro imidazo[1,5-a]pyridine-1- carboxamide and (S)-6-(3-((5-cyano-2-methoxypyridine)-3-sulfonamido)-2,6- difluorophenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyr idine-1-carboxamide [0527] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (200 mg, 0.65 mmol, 1 equiv) in pyridine (5 mL) was added a solution of 5-cyano-2-methoxypyridine-3-sulfonyl chloride (227 mg, 0.98 mmol, 1.5 equiv) in DCM (1 mL) dropwise at room temperature. The resulting solution was stirred for 1 h at room temperature, then quenched with water (20 mL). The resulting mixture was extracted with EA (3 x 20 mL), and the combined organics were washed with brine (2 x 10 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase 20-50% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; Detector 220 nm; and chiral-prep-HPLC with the following conditions: Column: CHIRALPAK IG, 250*30 mm, 5 μm; Mobile Phase 30% EtOH /3:1 Hexane: DCM; to afford (6R)-6-[3-(5-cyano-2-methoxypyridine-3-sulfonamido)-2,6-difl uorophenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (56 mg, 17% yield, stereochemistry randomly assigned) as a white solid and (6S)-6-[3-(5-cyano-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-methyl-5H,6H,7H,8H-imidaz o[1,5-a]pyridine-1- carboxamide (48 mg, 15% yield, stereochemistry randomly assigned) as a white solid. Assumed-(R)-6-(3-((5-cyano-2-methoxypyridine)-3-sulfonamido) -2,6-difluorophenyl)-N- methyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamid e LCMS (ES, m/z): [M+H] ⁺ : 503 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.41 (s, 1H), 8.93 (d, J = 2.2 Hz, 1H), 8.43 (d, J = 2.2 Hz, 1H), 7.74 (d, J = 4.9 Hz, 1H), 7.54 (s, 1H), 7.24 (dt, J = 8.9, 4.4 Hz, 1H), 7.08 (t, J = 9.5 Hz, 1H), 4.26 (dd, J = 12.3, 5.3 Hz, 1H), 4.01 (s, 3H), 3.95 (d, J = 12.0 Hz, 1H), 3.48 (s, 1H), 3.29 (s, 1H), 2.97-2.75 (m, 1H), 2.72 (t, J = 4.1 Hz, 3H), 2.15 – 1.88 (m, 2H). Assumed-(S)-6-(3-((5-cyano-2-methoxypyridine)-3-sulfonamido) -2,6-difluorophenyl)-N- methyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamid e LCMS (ES, m/z): [M+H] ⁺ : 503 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.41 (s, 1H), 8.94 (d, J = 2.2 Hz, 1H), 8.44 (d, J = 2.3 Hz, 1H), 7.74 (d, J = 4.8 Hz, 1H), 7.54 (s, 1H), 7.26 (d, J = 6.1 Hz, 1H), 7.11 (d, J = 9.6 Hz, 1H), 4.32-4.15 (m, 1H), 4.01 (s, 3H), 3.95 (d, J = 11.9 Hz, 1H), 3.48 (s, 1H), 3.31 (s, 1H), 2.97- 2.78 (m, 1H), 2.72 (t, J = 4.1 Hz, 3H), 2.14-1.89 (m, 2H). Example 84: Synthesis of 5-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a ] pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (Compound 69) Compound 69 Synthesis of 69-a: 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0528] To a stirred solution of 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]aniline (140 mg, 0.3 mmol, 1 equiv) in pyridine (3 mL) was added 5-cyano-2-methoxypyridine-3-sulfonyl chloride (95 mg, 0.4 mmol, 1.3 equiv) in portions at room temperature. The resulting mixture was stirred for 2 h at room temperature, then concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-70% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl) ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]pyrazin-6-yl]pheny l]-2-methoxypyridine-3- sulfonamide (109 mg, 54% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 639 Synthesis of Compound 69: 5-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a ] pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0529] Into an 8 mL vial, was placed 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (100 mg, 0.2 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 3 h at 25 °C, then concentrated, and the residue diluted with 3 mL of MeOH. The pH was adjusted to 8 with NH ₃ (7 M in MeOH), and this was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 5-45% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a ] pyrazin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide (62 mg, 78% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 509 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 9.55 (d, J = 1.6 Hz, 1H), 8.93 (d, J = 2.2 Hz, 1H), 8.66 (s, 1H), 8.61-8.39 (m, 2H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.31-6.97 (m, 3H), 4.03 (s, 3H). Example 85: Synthesis of N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro -2-methoxypyridine-3-sulfonamide (Compound 70) Int.1 Compound 70 Synthesis of 70-a: N-[2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]methyl]-1 ,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide [0530] Into an 8 mL vial were added 2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]methyl]- 1,2,4-triazol-3-yl) imidazo[1,5-a]pyridin-6-yl]aniline (150 mg, 0.34 mmol, 1 equiv), 5- chloro-2-methylpyridine-3-sulfonyl chloride (114 mg, 0.5 mmol, 1.5 equiv), DCM (5 mL) and pyridine (134 mg, 1.7 mmol, 5 equiv). The resulting mixture was stirred overnight at room temperature, then concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford N-[2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl) ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl ]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide (130 mg, 61% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 632 Synthesis of Compound 70: N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro -2-methoxypyridine-3-sulfonamide [0531] Into an 8 mL vial were added N-[2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide (120 mg, 0.19 mmol, 1 equiv) and TFA (2 mL). The resulting mixture was stirred for 30 min at 60 °C, then concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase: 20-50% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; Detector 220 nm; to afford N-[2,4-difluoro-3- [1-(4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide (37 mg, 39% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 502 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 14.34 (s, 1H), 10.44 (s, 1H), 8.64-8.58 (m, 2H), 8.48 (d, J = 3.0 Hz, 1H), 8.23 (d, J = 9.5 Hz, 1H), 8.04 (dd, J = 7.3, 3.0 Hz, 1H), 7.38 (td, J = 8.8, 5.9 Hz, 1H), 7.32-7.20 (m, 1H), 7.01-6.95 (m, 1H), 3.92 (s, 3H). Example 86: Synthesis of 5-cyano-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 71) Synthesis of 71-a: 5-cyano-N-[2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]m ethyl]-1,2,4- triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyr idine-3-sulfonamide [0532] Into an 8 mL vial were added 2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]methyl]- 1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]aniline (150 mg, 0.34 mmol, 1 equiv), 5-cyano- 2-methoxypyridine-3-sulfonyl chloride (118 mg, 0.5 mmol, 1.5 equiv), DCM (5.00 mL) and pyridine (134 mg, 1.7 mmol, 5 equiv). The resulting mixture was stirred overnight at room temperature, then concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 5-cyano-N-[2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (115 mg, 53% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 639 Synthesis of Compound 71: 5-cyano-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0533] Into an 8 mL vial were added 5-cyano-N-[2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (105 mg, 0.16 mmol, 1 equiv) and TFA (2 mL). The resulting mixture was stirred for 30 min at 60 °C, then concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase 20-50% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; Detector 220 nm; to afford 5-cyano-N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol- 3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3- sulfonamide (43 mg, 52% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 509. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ14.34 (s, 1H), 10.55 (s, 1H), 8.95 (d, J = 2.2 Hz, 1H), 8.60 (s, 2H), 8.52 (d, J = 2.2 Hz, 1H), 8.23 (d, J = 9.4 Hz, 1H), 7.40 (td, J = 8.8, 5.8 Hz, 1H), 7.33- 7.20 (m, 1H), 7.01-6.92 (m, 1H), 4.03 (s, 3H). Example 87: Synthesis of N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonami de (Compound 72) Compound 72 Synthesis of 72-a: 5-cyano-N-[2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]m ethyl]-1,2,4- triazol-3-yl) imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfo namide [0534] Into an 8 mL vial were added 2,4-difluoro-3-[1-(4-[[2-(trimethylsilyl)ethoxy]methyl]- 1,2,4-triazol-3-yl)imidazo[1,5-a] pyridin-6-yl]aniline (150 mg, 0.34 mmol, 1 equiv), 5-fluoro- 2-methylpyridine-3-sulfonyl chloride (213 mg, 1 mmol, 3 equiv), DCM (5 mL) and pyridine (134 mg, 1.7 mmol, 5 equiv). The resulting mixture was stirred overnight at room temperature, then concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 5-cyano-N-[2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl)ethoxy] methyl]-1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl ]-2- methoxypyridine-3-sulfonamide (115 mg, 53% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 616 Synthesis of Compound 72: N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonami de [0535] Into an 8 mL vial were added N-[2,4-difluoro-3-[1-(4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-5- fluoro-2-methylpyridine-3-sulfonamide (92 mg, 0.15 mmol, 1 equiv) and TFA (2 mL). The resulting mixture was stirred for 30 min at 60 °C, then concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase: 20-50% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; Detector 220 nm; to afford N-[2,4-difluoro-3-[1-(4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyrid ine-3-sulfonamide (27 mg, 37% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 486 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 14.32 (s, 1H), 10.79 (s, 1H), 8.76 (d, J = 2.8 Hz, 1H), 8.63- 8.56 (m, 2H), 8.22 (d, J = 9.5 Hz, 1H), 7.97 (dd, J = 8.2, 2.8 Hz, 1H), 7.44-7.21 (m, 2H), 6.98-6.88 (m, 1H), 2.78 (d, J = 1.2 Hz, 3H).

Example 88: Synthesis of 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-7- methyl-5H,6H,8H- imidazo[1,5-a]pyrazin-6-yl]phenyl] -2-methoxypyridine-3- sulfonamide and 5-chloro-N-[2,4-difluoro- 3-[(6S)-1-(1H-imidazol-2-yl)-7-methyl- 5H,6H,8H-imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxypyridin e-3-sulfonamide (Compounds 73-1 & 73-2) Synthesis of 73-a: tert-butyl N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyrazin-6-yl]phenyl]carbamate [0536] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]aniline (560 mg, 1.2 mmol, 1 equiv), EtOH (6 mL), (Boc) ₂ O (552 mg, 2.5 mmol, 2 equiv) and guanidine hydrochloride (24 mg, 0.2 mmol, 0.2 equiv). The resulting solution was stirred for 2 days at 50 °C, then cooled and concentrated. The residue was purified by prep-HPLC Flash-Prep- HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-60% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give tert-butyl N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]carbamate (490 mg, 71% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 543 Synthesis 73-b: of tert-butyl-N-[2,4-difluoro-3-[7-methyl-1-(1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)-5H,6H,8H-imidazo[1,5-a]pyrazin-6- yl]phenyl]carbamate [0537] Tert-butyl-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethox y]methyl]imidazol-2- yl)imidazo[1,5-a]pyrazin-6-yl] phenyl]carbamate (510 mg, 0.9 mmol, 1 equiv), 10% Pd/C (510 mg, 4.8 mmol, 5 equiv) and MeOH (10 mL) in a 50 mL sealed tube were hydrogenated under 20 atm at 50 °C overnight. HCHO (233 mg, 1.9 mmol, 2 equiv, 37% in water) was added and the resulting mixture was stirred under 20 atm hydrogen at 60 °C for a further 3 hrs. The reaction was cooled, filtered and concentrated under reduced pressure to give tert- butyl-N-[2,4-difluoro-3-[7-methyl-1-(1-[[2-(trimethylsilyl)e thoxy]methyl]imidazol-2-yl)- 5H,6H,8H-imidazo[1,5-a]pyrazin-6-yl]phenyl]carbamate (410 mg, 78% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 561 Synthesis of 73-c: tert-butyl-N-(5-chloro-2-methoxypyridin-3-ylsulfonyl)-N-[2,4 -difluoro-3- [7-methyl-1-(1- [[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,8H-im idazo[1,5- a]pyrazin-6-yl]phenyl] carbamate [0538] To a stirred solution of tert-butyl-N-[2,4-difluoro-3-[7-methyl-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,8H-imidaz o[1,5-a]pyrazin-6- yl]phenyl]carbamate (300 mg, 0.5 mmol, 1 equiv) in THF (7 mL) were added NaH (43 mg, 1 mmol, 2 equiv, 60% in oil) in portions at 0 °C.5-Chloro-2-methoxypyridine-3-sulfonyl chloride (155 mg, 0.6 mmol, 1.2 equiv) was added to the resulting solution in portions at 0 °C, then the reaction was allowed to stir to room temperature over 2 hrs. The reaction was poured into 100 mL water/ice and extracted with EA (2 x 100 mL). The extracts were dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure to give tert-butyl N-(5- chloro-2-methoxypyridin-3-ylsulfonyl)-N-[2,4-difluoro-3-[7-m ethyl-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,8H-imidaz o[1,5-a]pyrazin-6- yl]phenyl]carbamate (400 mg, 98% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 766 Synthesis of Compound 73-1 & 73-2: 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2- yl)-7-methyl-5H,6H,8H- imidazo[1,5-a]pyrazin-6-yl]phenyl] -2-methoxypyridine-3- sulfonamide and 5-chloro-N-[2,4-difluoro- 3-[(6S)-1-(1H-imidazol-2-yl)-7-methyl- 5H,6H,8H-imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxypyridin e-3-sulfonamide [0539] Into a 50 mL round-bottom flask was placed tert-butyl N-(5-chloro-2- methoxypyridin-3-ylsulfonyl)-N-[2,4-difluoro-3-[7-methyl-1-( 1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,8H-imidaz o[1,5-a]pyrazin-6-yl]phenyl] carbamate (400 mg, 0.5 mmol, 1 equiv), DCM (6 mL) and TFA (2 mL). The resulting solution was stirred for 5 h at room temperature, then concentrated. The residue was dissolved in 3 mL of MeOH and the pH was adjusted to 8 with NH ₃ (7 M in MeOH). This was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 5-35% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; and the enantiomers separated via chiral-Prep-HPLC with the following conditions: Column, CHIRALPAK IC-3, 4.6*50 mm, 3 µm; mobile phase: 50% EtOH (containing 0.1% diethylamine)/DCM; to give 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-7- methyl-5H,6H,8H-imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxy pyridine-3-sulfonamide (46 mg, 16% yield, stereochemistry randomly assigned) as an off-white solid and 5-chloro-N- [2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-7-methyl-5H,6H,8H -imidazo[1,5-a]pyrazin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide (48 mg, 17% yield, stereochemistry randomly assigned) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 536 for both isomers. 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-7-meth yl-5H,6H,8H-imidazo[1,5- a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.49 (d, J = 2.6 Hz, 1H), 7.97 (d, J = 2.6 Hz, 1H), 7.63 (s, 1H), 7.39 (td, J = 8.8, 5.7 Hz, 1H), 7.15 (td, J = 9.5, 9.0, 1.5 Hz, 1H), 6.97 (s, 2H), 4.40-4.22 (m, 2H), 4.19-3.99 (m, 2H), 3.94 (s, 3H), 3.56 (d, J = 15.9 Hz, 1H), 2.01 (s, 3H). 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-7-meth yl-5H,6H,8H-imidazo[1,5- a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.49 (d, J = 2.6 Hz, 1H), 7.96 (d, J = 2.6 Hz, 1H), 7.63 (s, 1H), 7.39 (td, J = 8.8, 5.7 Hz, 1H), 7.23-7.09 (m, 1H), 6.97 (s, 2H), 4.40-4.23 (m, 2H), 4.19- 4.00 (m, 2H), 3.94 (s, 3H), 3.56 (d, J = 15.9 Hz, 1H), 2.01 (s, 3H). Example 89: Synthesis of N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol -1-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5-fluoro-2-methoxypyridine-3-sulfonamide (Compound 74) Synthesis of Compound 74: N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol -1-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5-fluoro-2-methoxypyridine-3-sulfonamide [0540] To a stirred solution of 2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5-a]pyrid in- 6-yl]aniline (70 mg, 0.22 mmol, 1 equiv) and pyridine (71 mg, 0.9 mmol, 4 equiv) in DCM (1 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (75 mg, 0.34 mmol, 1.5 equiv) dropwise at room temperature. The resulting mixture was stirred for 2 h at room temperature, then diluted with water (2 mL). The resulting mixture was extracted with EtOAc (3 x 10 mL), and the extracts were washed with water and brine, dried over anhydrous Na ₂ SO ₄ before being concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, XSelect CSH Prep C18 OBD, 5 µm, 19*150 mm; mobile phase: 34-55% MeCN / 0.1% aqueous formic acid; Detector UV; to give N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro- 2- methoxypyridine-3-sulfonamide (22 mg, 69% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ :503. ¹ H NMR (300 MHz, DMSO-d6) δ 10.49 (s, 1H), 10.04 (s, 1H), 8.65 (s, 2H), 8.43 (d, J = 3.0 Hz, 1H), 8.01 (dd, J = 7.4, 3.0 Hz, 1H), 7.90 (d, J = 9.5 Hz, 1H), 7.43-7.29 (m, 1H), 7.21 (t, J = 9.2 Hz, 1H), 7.03 (dd, J = 9.3, 1.5 Hz, 1H), 3.89 (s, 3H). Example 90: Synthesis of 5-cyano-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo [1,5-a]pyridin-6-yl]phenyl] -2-methoxypyridine-3-sulfonamide (Compound 75) Synthesis Compound 75: of 5-cyano-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo [1,5- a]pyridin-6-yl]phenyl] -2-methoxypyridine-3-sulfonamide [0541] To a stirred solution of 2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5-a]pyrid in- 6-yl]aniline (70 mg, 0.23 mmol, 1 equiv) and pyridine (71 mg, 0.9 mmol, 4 equiv) in DCM (1 mL) was added 5-cyano-2-methoxypyridine-3-sulfonyl chloride (78 mg, 0.34 mmol, 1.5 equiv) dropwise at room temperature. The resulting mixture was stirred for 2 h at room temperature, then diluted with water (2 mL). The resulting mixture was extracted with EtOAc (3 x 10 mL), and the extracts washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, XSelect CSH Prep C18 OBD, 5 µm, 19*150 mm; mobile phase: 34-52% MeCN / 0.1% aqueous formic acid; Detector, UV; to give 5-cyano-N-[2,4- difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine- 3-sulfonamide (37 mg, 46% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 510. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.59 (s, 1H), 10.04 (s, 1H), 8.93 (d, J = 2.2 Hz, 1H), 8.65 (s, 2H), 8.50 (d, J = 2.2 Hz, 1H), 7.90 (d, J = 9.5 Hz, 1H), 7.39 (td, J = 8.9, 5.8 Hz, 1H), 7.25 (td, J = 9.2, 1.6 Hz, 1H), 7.07-6.97 (m, 1H), 4.02 (s, 3H). Example 91: Synthesis of N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]- 5-fluoro-2 -methylpyridine-3-sulfonamide (Compound 76) Synthesis of Compound 76: N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]- 5-fluoro-2 -methylpyridine-3-sulfonamide [0542] To a stirred solution of 2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5-a]pyrid in- 6-yl]aniline (70 mg, 0.22 mmol, 1 equiv) and pyridine (71 mg, 0.89 mmol, 4 equiv) in DCM (1 mL) was added 5-fluoro-2-methylpyridine-3-sulfonyl chloride (70 mg, 0.34 mmol, 1.5 equiv) dropwise at room temperature. The reaction was stirred for 2 h at room temperature, then diluted with water (2 mL). The resulting mixture was extracted with EtOAc (3 x 10 mL) and the extracts washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, XSelect CSH Prep C18 OBD, 5 µm, 19*150 mm ; mobile phase: 32- 51% MeCN / 0.1% aqueous formic acid; Detector, UV; to give N-[2,4-difluoro-3-[1-(1,2,3,4- tetrazol-1-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide (21 mg, 27% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 487. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.81 (s, 1H), 10.04 (s, 1H), 8.72 (d, J = 2.9 Hz, 1H), 8.64 (d, J = 2.1 Hz, 2H), 8.01 -7.85 (m, 2H), 7.43-7.29 (m, 1H), 7.30-7.18 (m, 1H), 6.99 (dd, J = 9.5, 1.5 Hz, 1H), 2.77 (d, J = 1.2 Hz, 3H). Example 92: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo [1,5-a]pyridin-6-yl] phenyl]- 2-methylpyridine-3-sulfonamide (Compound 77) Synthesis of Compound 77: 5-chloro-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo [1,5-a]pyridin-6-yl] phenyl]- 2-methylpyridine-3-sulfonamide [0543] To a stirred solution of 2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1,5-a]pyrid in- 6-yl]aniline (70 mg, 0.23 mmol, 1 equiv) and pyridine (71 mg, 0.89 mmol, 4 equiv) in DCM (1 mL) was added 5-chloro-2-methylpyridine-3-sulfonyl chloride (71 mg, 0.34 mmol, 1.5 equiv) dropwise at room temperature. The resulting mixture was stirred for 2 h at room temperature, then diluted with water (2 mL). The resulting mixture was extracted with EtOAc (3 x 10 mL), and the extracts were washed with water and brine, dried over anhydrous Na ₂ SO ₄ , and concentrated under reduced pressure. The crude product was purified by Prep- HPLC with the following conditions: Column, XSelect CSH Prep C18 OBD, 5 µm, 19*150 mm; mobile phase: 37-54% MeCN / 0.1% aqueous formic acid; Detector, UV; to give 5- chloro-N-[2,4-difluoro-3-[1-(1,2,3,4-tetrazol-1-yl)imidazo[1 ,5-a]pyridin-6-yl] phenyl]-2- methylpyridine-3-sulfonamide (30 mg, 27% yellow) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 503. 1H NMR (300 MHz, DMSO-d ₆ ) δ 10.82 (s, 1H), 10.04 (s, 1H), 8.76 (d, J = 2.4 Hz, 1H), 8.64 (s, 2H), 8.08 (d, J = 2.4 Hz, 1H), 7.90 (d, J = 9.5 Hz, 1H), 7.38 (td, J = 8.9, 5.9 Hz, 1H), 7.26 (td, J = 9.1, 1.5 Hz, 1H), 6.98 (dd, J = 9.5, 1.5 Hz, 1H), 2.77 (s, 3H). Example 93: Synthesis of N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyrazin - 6-yl] phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (Compound 78) Compound 78 Synthesis of 78-a: N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo[1,5-a] pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamid e [0544] To a stirred solution of 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a] pyrazin-6-yl]aniline (130 mg, 0.3 mmol, 1 equiv) in pyridine (3 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (99 mg, 0.4 mmol, 1.5 equiv) in portions at room temperature. The resulting solution was stirred for 3 h, then concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase, 5-70% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo[1,5-a] pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamid e (100 mg, 54% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 632 Synthesis of Compound 78: N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyrazin -6- yl] phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide [0545] Into an 8 mL vial, was placed N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a] pyrazin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (100 mg, 0.2 mmol, 1 equiv), DCM (1 mL) and TFA (3 mL). The resulting solution was stirred for 5 h at 25 °C, then was concentrated. The residue was diluted with 3 mL of MeOH and the pH adjusted to 8 with NH ₃ (7 M in MeOH). This was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250 mm, 10 µm; Mobile Phase: 5-40% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyrazin -6-yl]phenyl]-5- fluoro- 2-methoxypyridine-3-sulfonamide (45 mg, 57% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 502 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.73 (br s, 1H), 10.44 (br s, 1H), 9.55 (d, J = 1.6 Hz, 1H), 8.66 (s, 1H), 8.56 (t, J = 1.3 Hz, 1H), 8.47 (d, J = 2.9 Hz, 1H), 8.03 (dd, J = 7.3, 3.0 Hz, 1H), 7.40 (td, J = 8.9, 5.8 Hz, 1H), 7.31-7.04 (m, 3H), 3.92 (s, 3H). Example 94: Synthesis of 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyri dine-3-sulfonamide and 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compounds 79-1 & 79-2) Compound 79-2 Synthesis of 79-a: 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imida zol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]aniline [0546] Into a 30 mL pressure tank reactor was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (2.1 g, 5 mmol, 1 equiv), 10% Pd/C (1 g) and MeOH (20 mL), followed by an atmosphere of hydrogen. This was stirred overnight at 60 °C, then cooled and filtered. The filtrate was concentrated to give 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imida zol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]aniline (2.0 g, 85% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 446 Synthesis of 79-b: 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide [0547] Into a 25 mL 3-necked round-bottom flask was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]aniline (400 mg, 0.9 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (217 mg, 0.9 mmol, 1 equiv) and pyridine (213 mg, 2.7 mmol, 3 equiv) in DCM (10 mL). The resulting solution was stirred for 2 h at 45 °C, then concentrated under vacuum. The crude product was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm; Mobile Phase: 5-40% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy] methyl] imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl ]-2-methoxypyridine-3- sulfonamide (190 mg, 29% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 651 Synthesis of Compounds 79-1 & 79-2: 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2- yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxy pyridine-3-sulfonamide and 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0548] Into a 25 mL 3-necked round-bottom flask was placed 5-chloro-N-[2,4-difluoro-3-[1- (1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H ,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide (190 mg, 0.3 mmol, 1 equiv) and TFA (2 mL). The resulting solution was stirred for 30 min at 50 °C, then concentrated under vacuum. The pH was adjusted to 10 with ammonia and the crude product purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 5 μm; Mobile Phase: 5-35% MeCN/0.05% aqueous ammonia; Detector, 220 nm; to give 5-chloro-N-[2,4-difluoro- 3-[1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2- methoxypyridine-3-sulfonamide (83 mg, 49% yield) as a white solid. The enantiomers were separated by SFC with the following conditions: Column, CHIRALPAK IC, 20*250 mm, 5 μm; Mobile Phase: 50% 1:1 MeOH/EtOH / Hexane containing 0.1% diethylamine; to give 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2- yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxy pyridine-3-sulfonamide (19 mg, 23% yield, stereochemistry randomly assigned) as a white solid, and 5-chloro-N-[2,4- difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (20 mg, 23% yield, stereochemistry randomly assigned) as a white solid. 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 521 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.49 (d, J = 2.6 Hz, 1H), 8.02 (d, J = 2.5 Hz, 1H), 7.59 (s, 1H), 7.25 (td, J = 8.9, 5.8 Hz, 1H), 7.15-7.02 (m, 1H), 6.95 (s, 2H), 4.29 (dd, J = 12.3, 5.1 Hz, 1H), 4.00 (t, J = 11.9 Hz, 1H), 3.92 (s, 3H), 3.60-3.35 (m, 2H), 2.97-2.81 (m, 1H), 2.12 (d, J = 10.3 Hz, 1H), 2.05- 1.90 (m,1H). 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 521 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.49 (d, J = 2.6 Hz, 1H), 8.02 (d, J = 2.6 Hz, 1H), 7.59 (s, 1H), 7.32-7.18 (m, 1H), 7.08 (t, J = 9.5 Hz, 1H), 6.95 (s, 2H), 4.29 (dd, J = 12.3, 5.2 Hz, 1H), 4.00 (t, J = 11.9 Hz, 1H), 3.92 (s, 3H), 3.60-3.35 (m, 2H), 2.96-2.86 (m, 1H), 2.13 (d, J = 13.2 Hz, 1H), 1.90-2.20 (m, 1H).

Example 95: Synthesis of N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine -3-sulfonamide and N- [2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imida zo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide (Compounds 80-1 & 80-2) Synthesis of 80-a: N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-me thylpyridine-3-sulfonamide [0549] Into a 25 mL 3-necked round-bottom flask was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]aniline (400 mg, 0.9 mmol, 1 equiv), 5-fluoro-2-methylpyridine-3-sulfonyl chloride (188 mg, 0.9 mmol, 1 equiv) and pyridine (213 mg, 2.7 mmol, 3 equiv) in DCM (10 mL). The resulting solution was stirred for 2 h at 45 °C, then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 20-65% MeCN / 0.05% aqueous ammonia; Detector, 220 nm; to give N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methyl pyridine-3-sulfonamide (132 mg, 25% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 619 Synthesis of Compounds 80-1 & 80-2: N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-me thylpyridine-3-sulfonamide and N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide [0550] Into a 25 mL 3-necked round-bottom flask was placed N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy] methyl]imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide (132 mg, 0.2 mmol, 1 equiv) and TFA (2 mL). The resulting solution was stirred for 30 min at 50 °C, then concentrated under vacuum. The pH was adjusted to 10 with NH ₃ .H ₂ O and this purified by Flash-Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 5-30% MeCN / 0.05% aqueous ammonia; Detector, 220 nm; to give N-[2,4- difluoro-3-[1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]p yridin-6-yl]phenyl]-5-fluoro- 2-methylpyridine-3-sulfonamide (72 mg, 62% yield) as a white solid. The enantiomers were separated by SFC with the following conditions: Column, CHIRALPAK IC, 20*250 mm, 5 μm; Mobile Phase: 50% 1:1 MeOH/EtOH / 3:1 Hexane/DCM containing 0.1% diethylamine; Detector, 220 nm; to give N-[2,4-difluoro-3- [(6R)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin -6-yl]phenyl]-5-fluoro-2- methyl pyridine-3-sulfonamide (20 mg, stereochemistry randomly assigned) as a white solid and N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methyl pyridine-3-sulfonamide (19 mg, stereochemistry randomly assigned). N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methyl pyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 489 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.71 (d, J = 2.8 Hz, 1H), 7.87 (dd, J = 8.3, 2.9 Hz, 1H), 7.60 (s, 1H), 7.22 (td, J = 9.0, 5.8 Hz, 1H), 7.07 (t, J = 9.6 Hz, 1H), 7.00 (s, 2H), 4.26 (dd, J = 12.2, 5.1 Hz, 1H), 3.97 (t, J = 11.8 Hz, 1H), 3.45 (d, J = 28.1 Hz, 2H), 2.91 (q, J = 11.0, 9.6 Hz, 1H), 2.74 (d, J = 1.2 Hz, 3H), 2.11-1.92 (m, 2H). N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methyl pyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 489 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.71 (d, J = 2.8 Hz, 1H), 7.87 (dd, J = 8.3, 2.8 Hz, 1H), 7.60 (s, 1H), 7.23 (td, J = 8.9, 5.8 Hz, 1H), 7.08 (t, J = 9.4 Hz, 1H), 7.01 (s, 2H), 4.26 (dd, J = 12.3, 5.1 Hz, 1H), 4.04-3.89 (m, 1H), 3.49 (s, 2H), 2.90 (td, J = 11.4, 5.9 Hz, 1H), 2.74 (d, J = 1.2 Hz, 3H), 2.08 (d, J = 8.0 Hz, 1H), 1.99 (s, 1H). Example 96: Synthesis of N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridin e-3-sulfonamide and N- [2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imida zo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (Compounds 81-1 & 81-2) Synthesis of 81-a: N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-me thoxypyridine-3- sulfonamide [0551] Into a 25 mL 3-necked round-bottom flask, was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]aniline (400 mg, 0.9 mmol, 1 equiv), 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (202 mg, 0.9 mmol, 1 equiv) and pyridine (213 mg, 2.7 mmol, 3 equiv) in DCM (10 mL). The resulting solution was stirred for 2 h at 45 °C, then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, Sunfire Prep C18 OBD, 50*250 mm, 5 μm; mobile phase: 10-50% MeCN / 0.1% aqueous formic acid; Detector 220 nm; to give N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (230 mg, 36% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 635 Synthesis of Compounds 81-1 & 81-2: N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-me thoxypyridine-3- sulfonamide and N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide [0552] Into a 25 mL 3-necked round-bottom flask, was placed N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (230 mg, 0.36 mmol, 1 equiv) and TFA (2 mL). The resulting solution was stirred for 30 min at 50 °C, then concentrated under vacuum. The pH was adjusted to 10 with ammonia, and this was purified by Flash-Prep- HPLC with the following conditions: Column, welch xtimate C18, 50*250 mm, 5 μm; mobile phase: 5-30% MeCN / 0.05% aqueous ammonia ; Detector 220 nm; to give N-[2,4-difluoro- 3-[1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (120 mg, 62% yield) as a white solid. The enantiomers were separated by SFC with the following conditions: Column, CHIRALPAK IC, 20*250 mm, 5 μm, Mobile Phase: 1:1 MeOH/EtOH / 50% Hexane containing 0.1% diethylamine; Detector, 220 nm; to give N-[2,4-difluoro-3-[(6R)-1-(1H- imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl ]-5-fluoro-2- methoxypyridine-3-sulfonamide (27 mg, 22% yield, stereochemistry randomly assigned) as a white solid and N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide (27 mg, 22% yield, stereochemistry randomly assigned). N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 505 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.46 (d, J = 3.0 Hz, 1H), 7.97 (dd, J = 7.3, 3.0 Hz, 1H), 7.59 (s, 1H), 7.25 (td, J = 8.9, 5.8 Hz, 1H), 7.16-7.03 (m, 1H), 6.96 (s, 2H), 4.29 (dd, J = 12.2, 5.2 Hz, 1H), 4.00 (t, J = 11.9 Hz,1H), 3.92 (s, 3H), 3.60-3.30 (m, 2H), 2.90 (ddd, J = 17.5, 12.0, 6.2 Hz, 1H), 2.20-1.90 (m, 2H). N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 505 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.46 (d, J = 3.0 Hz, 1H), 7.97 (dd, J = 7.3, 3.0 Hz, 1H), 7.59 (s, 1H), 7.25 (td, J = 8.8, 5.7 Hz, 1H), 7.16-7.03 (m, 1H), 6.96 (s, 2H), 4.29 (dd, J = 12.3, 5.2 Hz, 1H), 4.07-3.94 (m, 1H), 3.92 (s, 3H), 3.60-3.30 (m, 2H), 2.90 (ddd, J = 17.8, 11.7, 6.2 Hz, 1H), 2.20-1.90 (m, 2H). Example 97: Synthesis of5-cyano-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyri dine-3-sulfonamide and 5-cyano-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7 H,8H-imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compounds 82-1 & 82-2) Synthesis of 82-a: 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide [0553] Into a 25 mL 3-necked round-bottom flask was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]aniline (400 mg, 0.9 mmol, 1 equiv), DCM (10 mL), 5-cyano-2-methoxypyridine-3- sulfonyl chloride (209 mg, 0.9 mmol, 1 equiv) and pyridine (213 mg, 2.7 mmol, 3 equiv). The resulting solution was stirred for 2 h at 45 °C, then quenched by the addition of 2 mL of CH ₃ OH. The resulting mixture was concentrated under vacuum, and the crude product was purified by Flash-Prep-HPLC with the following conditions: Column, C18 silica gel; mobile phase, 10-50% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-cyano-N- [2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imid azol-2-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfo namide (237 mg, 39% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 642 Synthesis of Compounds 82-1 & 82-2: 5-cyano-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2- yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxy pyridine-3-sulfonamide and 5-cyano-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7 H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0554] Into a 25 mL 3-necked round-bottom flask, was placed 5-cyano-N-[2,4-difluoro-3-[1- (1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H ,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide (237 mg, 0.37 mmol, 1 equiv) and TFA (2 mL). The resulting solution was stirred for 30 min at 50 °C, then concentrated under vacuum. The pH was adjusted to 10 with ammonia, and this was purified by Flash-Prep-HPLC with the following conditions: Column, C18; mobile phase: 5-35% MeCN / 0.05% aqueous ammonia; Detector, 220 nm; to give 5-cyano-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyri dine-3-sulfonamide (120 mg, 57% yield) as a white solid. The enantiomers were separated by SFC with the following conditions: Column, CHIRALPAK IC, 20*250 mm, 5 μm; Mobile Phase: 50% 1:1 MeOH:EtOH / 3:1 Hexane:DCM containing 0.1% diethylamine; Detector, 220 nm; to give 5-cyano-N-[2,4- difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H,7H,8H-imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (20 mg, stereochemistry randomly assigned) as a white solid and 5-cyano-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7 H,8H-imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (20 mg, stereochemistry randomly assigned) as a white solid. 5-cyano-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H,7 H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 512 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.92 (d, J = 2.2 Hz, 1H), 8.43 (d, J = 2.3 Hz, 1H), 7.59 (s, 1H), 7.31-7.21 (m, 1H), 7.09 (t, J = 9.4 Hz, 1H), 6.97 (s, 2H), 4.29 (dd, J = 12.1, 5.1 Hz, 1H), 4.02 (s, 4H), 3.46 (d, J = 30.2 Hz, 2H), 2.92 (d, J = 10.3 Hz, 1H), 2.06 (d, J = 26.6 Hz, 2H). 5-cyano-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7 H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methoxypyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 512 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.93 (d, J = 2.2 Hz, 1H), 8.44 (d, J = 2.2 Hz, 1H), 7.61 (s, 1H), 7.27 (td, J = 8.9, 5.9 Hz, 1H), 7.11 (t, J = 9.6 Hz, 1H), 7.00 (s, 2H), 4.29 (dd, J = 12.4, 5.2 Hz, 1H), 4.03 (s, 4H), 3.52 (s, 2H), 2.93 (d, J = 10.6 Hz, 1H), 2.11 (s, 1H), 2.01 (s, 1H). Example 98: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl] -2-methylpyridine-3-sulfonamide (Compound 83) Compound 83 Synthesis of 83-a: N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo[1,5-a] pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamid e [0555] To a stirred solution of 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin- 6-yl]aniline (120 mg, 0.3 mmol, 1 equiv) in pyridine (3 mL) was added 5-chloro-2-methylpyridine-3-sulfonyl chloride (92 mg, 0.4 mmol, 1.5 equiv) in portions at room temperature. The resulting solution was stirred for 3 h at room temperature, then concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-70% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl) ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]pyrazin-6-yl]pheny l]-2-methylpyridine-3- sulfonamide (85 mg, 49% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 632 Synthesis of Compound 83: 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl] -2-methylpyridine-3-sulfonamide [0556] Into a 50 mL round-bottom flask, was placed 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (85 mg), DCM (6 mL) and TFA (2 mL). The resulting solution was stirred for 5 h then concentrated. The residue was dissolved in 3 mL of MeOH and the pH was adjusted to 8 with NH ₃ (7 M in MeOH). This was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 10-50% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5- chloro-N-[2,4-difluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a] pyrazin-6-yl]phenyl] -2- methylpyridine-3-sulfonamide (25 mg, 37% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 502 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 9.54 (d, J = 1.6 Hz, 1H), 8.76 (d, J = 2.4 Hz, 1H), 8.67 (s, 1H), 8.55 (d, J = 1.5 Hz, 1H), 8.08 (d, J = 2.4 Hz, 1H), 7.40 (td, J = 8.9, 5.8 Hz, 1H), 7.31- 7.11 (m, 3H), 2.77 (s, 3H).

Example 99: 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H- imidazo [1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide and 5-chloro-N- [2,4-difluoro-3-[(6S)-1- (1H-imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide (Compound 84-1 & 84-2) Synthesis of 84-a: 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide [0557] Into a 25 mL 3-necked round-bottom flask, was placed 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6- yl]aniline (400 mg, 0.9 mmol, 1 equiv), 5-chloro-2-methylpyridine-3-sulfonyl chloride (203 mg, 0.9 mmol, 1 equiv) and pyridine (213 mg, 2.7 mmol, 3 equiv) in DCM (10 mL). The resulting solution was stirred for 2 h at 45 °C, then was cooled and quenched by the addition of 2 mL of CH ₃ OH. The resulting mixture was concentrated under vacuum and the crude product was purified by Flash-Prep-HPLC with the following conditions: Column, Sunfire Prep C18 OBD, 50*250 mm, 5 μm; mobile phase: 10-55% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5H,6H,7H,8H-imi dazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide (200 mg, 32% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 635 Synthesis of Compounds 84-1 & 84-2: 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2- yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylp yridine-3-sulfonamide and 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methylpyridine-3-sulfonamide [0558] Into a 25 mL 3-necked round-bottom flask, was placed 5-chloro-N-[2,4-difluoro-3-[1- (1-[[2-(trimethylsilyl)ethoxy] methyl]imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide (200 mg, 0.3 mmol, 1 equiv) and TFA (2 mL). The resulting solution was stirred for 30 min at 50 °C then cooled and concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, Sunfire Prep C18 OBD, 50*250 mm, 5 μm; mobile phase: 10-50% MeCN/0.1% aqueous formic acid; Detector 220 nm; to give 5-chloro-N-[2,4-difluoro-3-[1-(1H-imidazol- 2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl] -2-methylpyridine-3-sulfonamide (110 mg, 66% yield) as a white solid. The enantiomers were separated by SFC with the following conditions: Column, YMC-SC, 30*250 mm, 5 μm, Mobile Phase: 50% 1:1 MeOH:EtOH / 3:1 Hexane:DCM containing 0.1% diethylamine; Detector, 220 nm. This yielded 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H- imidazol-2-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl ]-2-methylpyridine-3- sulfonamide (17 mg, 15% yield, stereochemistry randomly assigned) as a white solid and 5- chloro-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H,7H ,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide (18 mg, 16% yield, stereochemistry randomly assigned) as a white solid. 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methylpyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 505 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.75 (d, J = 2.4 Hz, 1H), 7.99 (d, J = 2.4 Hz, 1H), 7.61 (s, 1H), 7.24 (td, J = 8.9, 5.8 Hz, 1H), 7.09 (t, J = 9.7 Hz, 1H), 7.02 (s, 2H), 4.27 (dd, J = 12.3, 5.1 Hz, 1H), 3.97 (t, J = 11.9 Hz, 1H), 3.54-3.15 (m, 2H), 2.90 (ddd, J = 17.5, 11.9, 6.4 Hz, 1H), 2.74 (s, 3H), 2.10-1.90 (m, 2H). 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(1H-imidazol-2-yl)-5H,6H, 7H,8H-imidazo[1,5-a]pyridin- 6-yl]phenyl]-2-methylpyridine-3-sulfonamide: LCMS (ES, m/z): [M+H] ⁺ : 505 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.75 (d, J = 2.4 Hz, 1H), 7.99 (d, J = 2.4 Hz, 1H), 7.61 (s, 1H), 7.24 (td, J = 8.9, 5.8 Hz, 1H), 7.16-7.04 (m, 1H), 7.02 (s, 2H), 4.27 (dd, J = 12.2, 5.2 Hz, 1H), 3.97 (t, J = 11.9 Hz, 1H), 3.60-3.20 (2H, m), 2.90 (ddd, J = 17.5, 11.5, 6.4 Hz, 1H), 2.74 (s, 3H), 2.15-1.90 (m, 2H). Example 100: Synthesis of 5-chloro-N-[2,4-difluoro-3-[5-(1H- imidazol-2-yl)imidazo[1,5- b]pyridazin-2-yl]phenyl] -2-methoxypyridine-3-sulfonamide (Compound 85) Compound 85 Synthesis of 85-a: 5-chloro-N-[2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-b]pyridazin-2-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0559] To a stirred solution of 2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-b]py ridazin- 2-yl]aniline (130 mg, 0.3 mmol, 1 equiv) in pyridine (3 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (106 mg, 0.4 mmol, 1.5 equiv) in portions at room temperature. The resulting mixture was stirred overnight at room temperature, then concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-70% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-chloro-N-[2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-b]py ridazin-2-yl]phenyl]-2- methoxypyridine-3-sulfonamide (95 mg, 50% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 648 Synthesis of Compound 85: 5-chloro-N-[2,4-difluoro-3-[5-(1H- imidazol-2-yl)imidazo[1,5- b]pyridazin-2-yl]phenyl] -2-methoxypyridine-3-sulfonamide [0560] Into a 50 mL round-bottom flask, was placed 5-chloro-N-[2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-b]pyridazin-2-yl]phenyl]-2- methoxypyridine-3-sulfonamide (95 mg, 0.15 mmol, 1 equiv), DCM (6 mL) and TFA (2 mL). The resulting solution was stirred for 2 h, then was concentrated. The residue was dissolved in 3 mL of MeOH and the pH adjusted to 8 with NH ₃ (7 M in MeOH). This was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 10-40% MeCN /0.1% aqueous formic acid; Detector, 220 nm. This gave 5-chloro-N-[2,4-difluoro-3-[5-(1H-imidazol-2-yl)imidazo[1,5- b]pyridazin-2- yl]phenyl]-2-methoxypyridine-3-sulfonamide (40 mg, 53% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ 518 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.89 (s, 1H), 8.66 (d, J = 9.4 Hz, 1H), 8.52 (d, J = 2.6 Hz, 1H), 8.10 (d, J = 2.6 Hz, 1H), 7.50 (td, J = 8.9, 5.8 Hz, 1H), 7.38-7.24 (m, 1H), 7.14 (s, 2H), 6.96 (d, J = 9.4 Hz, 1H), 3.93 (s, 3H).

Example 101: Synthesis of (R)-6-(2,6-difluoro-3-((5-fluoro-2-methylpyridine)-3- sulfonamido)phenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a ]pyridine-1- carboxamide and (S)-6-(2,6-difluoro-3-((5-fluoro-2-methylpyridine)-3- sulfonamido)phenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a ]pyridine-1- carboxamide (Compounds 86-1 & 86-2) Synthesis of Compounds 86-1 & 86-2: (R)-6-(2,6-difluoro-3-((5-fluoro-2-methylpyridine)-3- sulfonamido)phenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a ]pyridine-1-carboxamide and (S)-6-(2,6-difluoro-3-((5-fluoro-2-methylpyridine)-3-sulfona mido)phenyl)-N-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide [0561] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (200 mg, 0.65 mmol, 1 equiv) in pyridine (10 mL) was added a solution of 5-fluoro-2-methylpyridine-3-sulfonyl chloride (205 mg, 0.98 mmol, 1.5 equiv) in DCM (2 mL) dropwise at room temperature. The resulting solution was stirred for 1 h then quenched with water (20 mL). This was extracted with EA (3 x 20 mL), and the combined organics were washed with brine (2 x 10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, Sunfire Prep C18 OBD, 50*250 mm 5 µm 10 nm; Mobile Phase: 10-40% MeCN / 0.1% aqueous formic acid, Flow rate: 90 mL/min; Detector 220 nm; to give racemic 6-(2,6-difluoro-3-((5-fluoro-2-methylpyridine)-3-sulfonamido )phenyl)-N- methyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxamid e. The enantiomers were separated by chiral-prep-HPLC with the following conditions: Column, CHIRALPAK IE 250*30 mm, 5 μm; Mobile Phase 10% EtOH / 5:1 Hexane:DCM; to afford (6R)-6-[2,6- difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido)phenyl]- N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (52 mg, 17% yield, stereochemistry randomly assigned) as a white solid and (6S)-6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyrid ine-1-carboxamide (61 mg, 19% yield, stereochemistry randomly assigned) as a white solid. (R)-6-(2,6-difluoro-3-((5-fluoro-2-methylpyridine)-3-sulfona mido)phenyl)-N-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide: LCMS (ES, m/z): [M+H] ⁺ : 480 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.64 (s, 1H), 8.75 (d, J = 2.8 Hz, 1H), 7.87 (dd, J = 8.2, 2.9 Hz, 1H), 7.73 (q, J = 4.7 Hz, 1H), 7.53 (s, 1H), 7.25 (td, J = 8.8, 5.7 Hz, 1H), 7.09 (t, J = 9.4 Hz, 1H), 4.23 (dd, J = 12.4, 5.2 Hz, 1H), 3.93 (t, J = 11.9 Hz, 1H), 3.54 – 3.42 (m, 1H), 3.37 – 3.24 (m, 1H), 2.88 (d, J = 11.8 Hz, 1H), 2.74 (d, J = 1.2 Hz, 3H), 2.71 (d, J = 4.8 Hz, 3H), 1.98 (d, J = 28.3 Hz, 2H). (S)-6-(2,6-difluoro-3-((5-fluoro-2-methylpyridine)-3-sulfona mido)phenyl)-N-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide LCMS (ES, m/z): [M+H] ⁺ : 480 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.63 (s, 1H), 8.71 (d, J = 2.8 Hz, 1H), 7.87 (dd, J = 8.3, 2.8 Hz, 1H), 7.73 (q, J = 4.8 Hz, 1H), 7.53 (s, 1H), 7.22 (td, J = 8.9, 5.7 Hz, 1H), 7.06 (t, J = 9.6 Hz, 1H), 4.23 (dd, J = 12.3, 5.2 Hz, 1H), 3.94 (t, J = 11.9 Hz, 1H), 3.52-3.42 (m, 1H), 3.34-3.28 (m, 1H), 2.85 (ddd, J = 17.8, 11.7, 6.3 Hz, 1H), 2.74 (d, J = 1.2 Hz, 3H), 2.71 (d, J = 4.7 Hz, 3H), 1.97 (d, J = 17.4 Hz, 2H).

Example 102: Synthesis of 5-chloro-N-[3-[1-(5-cyclopropyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]- 2,4-difluorophenyl]-2-methoxypyridine-3-sulfonamide (Compound 87) Synthesis of 87-a: 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-cyclopropyl-4H-1,2,4 -triazole [0562] Into a 40 mL vial were added cyclopropaneamidine hydrochloride (1.4 g, 11.6 mmol, 6 equiv), MeOH (20 mL) and 30% NaOMe in MeOH (2.1 g, 11.7 mmol, 6 equiv). The resulting mixture was stirred for 1 h at room temperature. The mixture was filtered, and to the filtrate was added 6-bromoimidazo[1,5-a]pyridine-1-carbohydrazide (500 mg, 2 mmol, 1 equiv). The resulting mixture was stirred for 48 h at 80 °C, before being cooled and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 3-[6-bromoimidazo[1,5-a]pyridin-1- yl]-5-cyclopropyl-4H-1,2,4-triazole (410 mg, 69% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 304, 306 Synthesis of 87-b: 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-cyclopropyl-4-[[2- (trimethylsilyl)ethoxy] methyl]-1,2,4-triazole [0563] Into a 40 mL vial were added 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-cyclopropyl- 4H-1,2,4-triazole (340 mg, 1.1 mmol, 1 equiv) and THF (5 mL). To this was added 60% NaH in oil (78 mg, 3.2 mmol, 2.9 equiv) in portions at 0 °C. The resulting mixture was stirred for 30 min at 0 °C, then [2-(chloromethoxy)ethyl]trimethylsilane (203 mg, 1.2 mmol, 1.1 equiv) was added dropwise at 0 °C. After an additional 30 min at 0 °C, the reaction was quenched with water (100 mL) and extracted with EtOAc (3 x 100 mL). The combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-cyclopropyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazole (370 mg, 77% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 434, 436 Synthesis of 87-c: 3-[1-(5-cyclopropyl-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2 ,4-triazol-3- yl)imidazo [1,5-a]pyridin-6-yl]-2,4-difluoroaniline [0564] Into a 40 mL vial were added 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-cyclopropyl- 4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazole (360 mg, 0.8 mmol, 1 equiv), 2,4-difluoro- 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (422 mg, 1.6 mmol, 2 equiv), Pd(dtbpf)Cl ₂ (54 mg, 0.08 mmol, 0.1 equiv), K ₂ CO ₃ (343 mg, 2.5 mmol, 3 equiv), dioxane (7.00 mL) and H ₂ O (1.4 mL). The resulting mixture was stirred for 16 h at 80 °C under nitrogen atmosphere. The mixture was cooled and diluted with water (100 mL), then extracted with EtOAc (3 x 100 mL). The combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 3-[1- (5-cyclopropyl-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-tr iazol-3-yl)imidazo[1,5-a]pyridin- 6-yl]-2,4-difluoroaniline (350 mg, 88% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 483 Synthesis of 87-d: 5-chloro-N-[3-[1-(5-cyclopropyl-4-[[2-(trimethylsilyl)ethoxy ]methyl]- 1,2,4-triazol-3-yl) imidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-2-methoxypyr idine-3- sulfonamide [0565] Into an 8 mL vial were added 3-[1-(5-cyclopropyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a] pyridin-6-yl]-2,4- difluoroaniline (150 mg, 0.3 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (105 mg, 0.43 mmol, 1.4 equiv), DCM (3 mL) and pyridine(120 mg, 1.5 mmol, 4.9 equiv). The resulting mixture was stirred overnight then concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE/THF (10:7) to afford 5- chloro-N-[3-[1-(5-cyclopropyl-4-[[2-(trimethylsilyl)ethoxy]m ethyl]-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-2-methoxy pyridine-3-sulfonamide (160 mg, 75% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 688. Synthesis of Compound 87: 5-chloro-N-[3-[1-(5-cyclopropyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]- 2,4-difluorophenyl]-2-methoxypyridine-3-sulfonamide [0566] Into an 8 mL vial were added 5-chloro-N-[3-[1-(5-cyclopropyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl) imidazo[1,5-a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide (150 mg, 0.2 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 60 °C, then concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase: 5-30% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; detector 220 nm; to afford 5-chloro-N-[3-[1-(5- cyclopropyl-4H-1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl ]-2,4-difluorophenyl]-2- methoxypyridine-3-sulfonamide (56 mg, 46% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 558. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.88-13.47 (m, 1H), 10.45 (s, 1H), 8.71-8.45 (m, 2H), 8.17 (d, J = 9.5 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.40 (dd, J = 9.0, 5.8 Hz, 1H), 7.33-7.18 (m, 1H), 7.09-6.77 (m, 1H), 3.93 (s, 3H), 2.19-1.99 (m, 1H), 1.20-0.74 (m, 3H).

Example 103: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(5-isopropyl-4H-1,2,4-triazol- 3- yl)imidazo[1,5-a] pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 88) Compound 88 Synthesis of 88-a: 6-bromoimidazo[1,5-a]pyridine-1-carbohydrazide [0567] Into a 100 mL round-bottom flask were added ethyl 6-bromoimidazo[1,5-a]pyridine- 1-carboxylate (3 g, 11 mmol, 1 equiv), hydrazine hydrate (30 mL) and EtOH (30 mL). The resulting mixture was stirred for 2 h at 80 °C, then cooled and diluted with water (200 mL). The precipitated solids were collected by filtration, washed with water (2 x 10 mL) and dried to give 6-bromoimidazo[1,5-a]pyridine-1-carbohydrazide (320 mg, 68% yield) as an off- white solid. LCMS (ES, m/z): [M+H] ⁺ : 255, 257 Synthesis of 88-b: 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-isopropyl-4H-1,2,4-t riazole [0568] Into a 40 mL vial were added 2-methylpropanimidamide hydrochloride (1.4 g, 11.7 mmol, 6 equiv), MeOH (20 mL) and 30% NaOMe in MeOH (2.1 g, 11.7 mmol, 6 equiv). The resulting mixture was stirred for 1 h, then filtered. To the filtrate was added 6- bromoimidazo[1,5-a]pyridine-1-carbohydrazide (500 mg, 2 mmol, 1 equiv) and the resulting mixture was stirred for 48 h at 80 °C . After cooling, the reaction was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-isopropyl-4H-1,2,4- triazole (390 mg, 65% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 306, 308. Synthesis of 88-c: 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-isopropyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazole [0569] Into a 40 mL vial were added 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-isopropyl-4H- 1,2,4-triazole (320 mg, 1 mmol, 1 equiv) and THF (5 mL). To the above mixture was added 60% NaH (74 mg, 3 mmol, 3 equiv) in portions at 0 °C. The resulting mixture was stirred for 30 min at 0 °C before [2-(chloromethoxy)ethyl]trimethylsilane (191 mg, 1.1 mmol, 1.1 equiv) was added dropwise. The reaction was stirred for 30 min at 0 °C, then quenched with water. The resulting mixture was diluted further with water (100 mL), and extracted with EtOAc (3 x 100 mL). The combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 3-[6- bromoimidazo[1,5-a]pyridin-1-yl]-5-isopropyl-4-[[2-(trimethy lsilyl)ethoxy]methyl]-1,2,4- triazole (340 mg, 74% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 436, 438. Synthesis of 88-d: 2,4-difluoro-3-[1-(5-isopropyl-4-[[2-(trimethylsilyl)ethoxy] methyl]-1,2,4- triazol-3-yl) imidazo[1,5-a]pyridin-6-yl]aniline [0570] Into a 40 mL vial were added 3-[6-bromoimidazo[1,5-a]pyridin-1-yl]-5-isopropyl-4- [[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazole (330 mg, 0.7 mmol, 1 equiv), 2,4-difluoro-3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (385 mg, 1.5 mmol, 2 equiv), Pd(dtbpf)Cl ₂ (50 mg, 0.08 mmol, 0.1 equiv), K ₂ CO ₃ (313 mg, 2.3 mmol, 3 equiv), dioxane (7 mL) and H ₂ O (1.4 mL). The resulting mixture was stirred for 16 h at 80 °C under nitrogen atmosphere. The mixture was allowed to cool and was diluted with water (100 mL). The resulting mixture was extracted with EtOAc (3 x 100 mL), and the combined organics washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 2,4-difluoro-3-[1-(5-isopropyl-4-[[2-(trimethylsilyl)ethoxy] methyl]- 1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]aniline (330 mg, 90% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 485. Synthesis of 88-e: 5-chloro-N-[2,4-difluoro-3-[1-(5-isopropyl-4-[[2- (trimethylsilyl)ethoxy]methyl] -1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0571] Into an 8 mL vial were added 2,4-difluoro-3-[1-(5-isopropyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]aniline (150 mg, 0.3 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (112 mg, 0.5 mmol, 1.5 equiv), DCM (3 mL) and pyridine (122 mg, 1.5 mmol, 5 equiv). The resulting mixture was stirred overnight at room temperature, then concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE/THF (10:7) to afford 5-chloro- N-[2,4-difluoro-3-[1-(5-isopropyl-4-[[2-(trimethylsilyl)etho xy]methyl]-1,2,4-triazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (170 mg, 80% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 690. Synthesis of Compound 88: 5-chloro-N-[2,4-difluoro-3-[1-(5-isopropyl-4H-1,2,4-triazol- 3- yl)imidazo[1,5-a] pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0572] Into an 8 mL vial were added 5-chloro-N-[2,4-difluoro-3-[1-(5-isopropyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (160 mg, 0.23 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 60 °C, then was concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Atlantis HILIC OBD, 19*150 mm*5 µm; Mobile Phase: 5-30% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; Detector 220 nm; to afford 5-chloro-N-[2,4-difluoro-3-[1-(5- isopropyl-4H-1,2,4-triazol-3-yl)imidazo[1,5-a]pyridin-6-yl]p henyl]-2-methoxy pyridine-3- sulfonamide (82 mg, 63% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 560. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.93-13.46 (m, 1H), 10.46 (s, 1H), 8.65-8.41 (m, 3H), 8.22 (d, J = 9.5 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.39 (td, J = 8.8, 5.8 Hz, 1H), 7.26 (td, J = 9.1, 1.5 Hz, 1H), 7.09-6.85 (m, 1H), 3.93 (s, 3H), 3.20-2.93 (m, 1H), 1.33 (d, J = 7.0 Hz, 6H). Example 104: Synthesis of (R)-6-(3-((5-chloro-2-methylpyridine)-3-sulfonamido)-2,6- difluorophenyl)-N-methyl-5,6,7,8-tetrahydro imidazo[1,5-a]pyridine-1-carboxamide & (S)-6-(3-((5-chloro-2-methylpyridine)-3-sulfonamido)-2,6-dif luorophenyl)-N-methyl- 5,6,7,8-tetrahydro imidazo[1,5-a]pyridine-1-carboxamide (Compounds 89-1 & 89-2) Synthesis of Compounds 89-1 & 89-2: (R)-6-(3-((5-chloro-2-methylpyridine)-3- sulfonamido)-2,6-difluorophenyl)-N-methyl-5,6,7,8-tetrahydro imidazo[1,5-a]pyridine-1- carboxamide and (S)-6-(3-((5-chloro-2-methylpyridine)-3-sulfonamido)-2,6-dif luorophenyl)- N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine-1-carboxam ide [0573] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (200 mg, 0.65 mmol, 1 equiv) in pyridine (6 mL) was added a solution of 5-chloro-2-methylpyridine-3-sulfonyl chloride (221 mg, 0.98 mmol, 1.5 equiv) in DCM (1 mL) dropwise at room temperature. The resulting solution was stirred for 1 h then quenched with water (20 mL). The resulting mixture was extracted with EA (3 x 20 mL), and the combined organics washed with brine (2 x 10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, Sunfire Prep C18 OBD, 50*250 mm 5 µm 10 nm; Mobile Phase: 15-30% MeCN / 0.1% aqueous formic acid; to give the racemate of the title compounds. The enantiomers were separated by chiral prep-HPLC using the following conditions: Column, CHIRALPAK IE 250*30 mm, 5 μm, Mobile Phase: 30% EtOH / 5:1 Hexane:DCM; to afford (6R)-6-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine- 1-carboxamide (50 mg, 15% yield, stereochemistry randomly assigned) as a white solid and (6S)-6-[3-(5-chloro-2- methylpyridine-3-sulfonamido)-2,6-difluorophenyl]-N-methyl-5 H,6H,7H,8H-imidazo[1,5- a]pyridine-1-carboxamide (49 mg, 15% yield, stereochemistry randomly assigned) as a white solid. (R)-6-(3-((5-chloro-2-methylpyridine)-3-sulfonamido)-2,6-dif luorophenyl)-N-methyl-5,6,7,8- tetrahydro imidazo[1,5-a]pyridine-1-carboxamide LCMS (ES, m/z): [M+H] ⁺ : 496 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.65 (s, 1H), 8.78 (d, J = 2.4 Hz, 1H), 7.98 (d, J = 2.4 Hz, 1H), 7.74 (q, J = 4.7 Hz, 1H), 7.53 (s, 1H), 7.27 (td, J = 8.8, 5.8 Hz, 1H), 7.13 (td, J = 9.5, 9.0, 1.5 Hz, 1H), 4.23 (dd, J = 12.3, 5.2 Hz, 1H), 3.93 (t, J = 11.9 Hz, 1H), 3.46 (t, J = 11.7 Hz, 1H), 3.28 (dd, J = 4.7, 2.2 Hz, 1H), 2.86 (ddd, J = 17.7, 11.4, 6.5 Hz, 1H), 2.76-2.68 (m, 6H), 1.97 (dd, J = 21.9, 7.8 Hz, 2H). (S)-6-(3-((5-chloro-2-methylpyridine)-3-sulfonamido)-2,6-dif luorophenyl)-N-methyl-5,6,7,8- tetrahydro imidazo[1,5-a]pyridine-1-carboxamide LCMS (ES, m/z): [M+H] ⁺ : 496 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.64 (s, 1H), 8.74 (d, J = 2.4 Hz, 1H), 7.99 (d, J = 2.4 Hz, 1H), 7.73 (q, J = 4.7 Hz, 1H), 7.53 (s, 1H), 7.23 (td, J = 8.9, 5.8 Hz, 1H), 7.14-7.01 (m, 1H), 4.23 (dd, J = 12.4, 5.2 Hz, 1H), 3.94 (t, J = 11.9 Hz, 1H), 3.46 (t, J = 11.5 Hz, 1H), 3.38-3.26 (m, 1H), 2.86 (ddd, J = 17.8, 11.5, 6.3 Hz, 1H), 2.77-2.67 (m, 6H), 1.98 (dd, J = 25.8, 9.4 Hz, 2H).

Example 105: Synthesis of 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-N-methylimidazo [1,5-a]pyrazine-1-carboxamide (Compound 90) Compound 90 Synthesis of 90-a: 2-(5-bromopyrazin-2-yl)-2-[(diphenylmethylidene)amino]acetat e [0574] To a stirred mixture of 2,5-dibromopyrazine (10 g, 42 mmol, 1 equiv) and K ₂ CO ₃ (17.4 g, 126 mmol, 3 equiv) in NMP (100 mL) were added methyl 2- [(diphenylmethylidene)amino]acetate (12.8 g, 50 mmol, 1.2 equiv) and tetrabutylammonium bromide (13.6 g, 42 mmol, 1 equiv) in portions at room temperature under nitrogen atmosphere. The reaction was stirred for overnight at 100 °C under nitrogen atmosphere. The resulting mixture was diluted with water (1 L) and extracted with CH ₂ Cl ₂ (3 x 200 mL). The combined organics were washed with brine (2 x 200 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (5:1) to afford methyl 2-(5-bromopyrazin-2-yl)-2- [(diphenylmethylidene)amino]acetate (12 g, 70% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 410, 412 Synthesis of 90-b: 2-amino-2-(5-bromopyrazin-2-yl)acetate [0575] To a stirred solution of methyl 2-(5-bromopyrazin-2-yl)-2- [(diphenylmethylidene)amino]acetate (12 g, 29 mmol, 1 equiv) in DCM (300 mL) was added 6 M HCl (20 mL) dropwise at room temperature. The resulting mixture was stirred for 1 h then diluted with water (100 mL). The mixture was basified to pH 10 with ammonia, then extracted with CH ₂ Cl ₂ (3 x 20 mL). The combined organics were washed with brine (2 x 20 mL), dried (Na ₂ SO ₄ ) and concentrated under vacuum. The residue was washed with ethyl ether (3x5 mL) and air dried to give methyl 2-amino-2-(5-bromopyrazin-2-yl)acetate (6 g, 83% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 246, 248 Synthesis of 90-c: 6-bromoimidazo[1,5-a]pyrazine-1-carboxylate [0576] Into a 50 mL round-bottom flask were added methyl 2-amino-2-(5-bromopyrazin-2- yl)acetate (6 g, 25 mmol, 1 equiv) and diethoxy(methoxy)methane (10 mL) at room temperature. The resulting mixture was stirred for 16 h at 110 °C, then cooled and diluted with diethyl ether (10 mL). The precipitated solids were collected by filtration and washed with diethyl ether (3 x 5 mL). Drying gave methyl 6-bromoimidazo[1,5-a]pyrazine-1- carboxylate (3 g, 48% yield) as a red solid. LCMS (ES, m/z): [M+H] ⁺ : 256, 258 Synthesis of 90-d: 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1-carbo xylate [0577] To a stirred mixture of methyl 6-bromoimidazo[1,5-a]pyrazine-1-carboxylate (500 mg, 2 mmol, 1 equiv) and 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) aniline (747 mg, 3 mmol, 1.5 equiv) in 1,4-dioxane (10 mL) were added K ₃ PO ₄ (828 mg, 4 mmol, 2 equiv) and Pd(dtbpf)Cl ₂ (127 mg, 0.2 mmol, 0.1 equiv) in portions at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 3 h at 90 °C then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:1) to afford methyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5- a]pyrazine-1-carboxylate (500 mg) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 305 Synthesis of 90-e: 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5-a]pyrazin e-1- carboxamide [0578] A mixture of methyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1- carboxylate (500 mg, 0.25 mmol, 1 equiv) and 40% methylamine aqueous solution (5 mL) in THF (10 mL) was stirred for 1 day at room temperature, then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:10) to afford 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5-a]pyrazin e- 1-carboxamide (460 mg) as a white solid. LCMS (ES, m/z): [M+H]+: 304 Synthesis of Compound 90: 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-N-methylimidazo [1,5-a]pyrazine-1-carboxamide [0579] To a stirred solution 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (75 mg, 0.25 mmol, 1 equiv) in pyridine (2 mL) was added 5- fluoro-2-methoxypyridine-3-sulfonyl chloride (67 mg, 0.3 mmol, 1.2 equiv) in portions at room temperature. The resulting mixture was stirred for 1 h at room temperature then diluted with MeOH (2 mL) and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 10-50% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 6-[2,6-difluoro-3-(5- fluoro-2-methoxypyridine-3-sulfonamido)phenyl]-N-methylimida zo [1,5-a]pyrazine-1- carboxamide (94 mg, 77% yield) as a white solid. LCMS (ES, m/z): [M+H]+: 493 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.43 (s, 1H), 9.51 (d, J = 1.7 Hz, 1H), 8.67-8.65 (m, 2H), 8.46 (d, J = 3.0 Hz, 1H), 8.44-8.41 (m, 1H), 8.03 (dd, J = 7.3, 3.0 Hz, 1H) 7.45-7.37 (m, 1H), 7.30-7.18 (m, 1H), 3.91 (s, 3H), 2.84 (d, J = 4.8 Hz, 3H). Example 106: Synthesis of 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-N-methylimidazo [1,5-a]pyrazine-1-carboxamide (Compound 91) Synthesis of Compound 91: 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-N-methylimidazo [1,5-a]pyrazine-1-carboxamide [0580] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (115 mg, 0.38 mmol, 1 equiv) in pyridine (2 mL) was added 5- fluoro-2-methylpyridine-3-sulfonyl chloride (238 mg, 1.1 mmol, 3 equiv) dropwise at room temperature. The resulting mixture was stirred for 1 h then concentrated, and the residue was purified by reverse phase flash chromatography with the following conditions: column, C18 silica gel; mobile phase: 10-50% MeOH in water; detector, UV 220 nm; to give 6-[2,6- difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido) phenyl]-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (99 mg, 55% yield) as a white solid. LCMS (ES, m/z): [M+H]+: 477 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.80 (s, 1H), 9.50 (d, J = 1.6 Hz, 1H), 8.72 (d, J = 2.8 Hz, 1H), 8.65 (d, J = 1.9 Hz, 2H), 8.42 (q, J = 4.6 Hz, 1H), 7.95 (dd, J = 8.2, 2.8 Hz, 1H), 7.40 (td, J = 8.9, 5.8 Hz, 1H), 7.24 (td, J = 9.1, 1.6 Hz, 1H), 2.84 (d, J = 4.8 Hz, 3H), 2.78 (d, J = 1.2 Hz, 3H).

Example 107: Synthesis of 6-[3-(5-cyano-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 92) Synthesis of Compound 92: 6-[3-(5-cyano-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide [0581] To a stirred solution 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (75 mg, 0.25 mmol, 1 equiv) in pyridine (2 mL) was added 5- cyano-2-methoxypyridine-3-sulfonyl chloride (69 mg, 0.3 mmol, 1.2 equiv) in portions at room temperature. The resulting mixture was stirred for 3 h then diluted with MeOH (2 mL), before being concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 10-50% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford 6-[3-(5-cyano-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-methyli midazo[1,5-a]pyrazine-1- carboxamide (78 mg, 63% yield) as a white solid. LCMS (ES, m/z): [M+H]+: 500 1H NMR (300 MHz, DMSO-d ₆ ) δ 10.54 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.93 (d, J = 2.2 Hz, 1H), 8.66 (d, J = 2.8 Hz, 2H), 8.51 (d, J = 2.2 Hz, 1H), 8.41 (d, J = 4.8 Hz, 1H), 7.43 (td, J = 8.9, 5.8 Hz, 1H), 7.24 (td, J = 9.0, 1.6 Hz, 1H), 4.02 (s, 3H), 2.84 (d, J = 4.8 Hz, 3H).

Example 108: Synthesis of 6-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 93) Synthesis of Compound 93: 6-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide [0582] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (120 mg, 0.4 mmol, 1 equiv) in pyridine (2 mL) was added 5- chloro-2-methylpyridine-3-sulfonyl chloride (134 mg, 0.6 mmol, 1.5 equiv) dropwise at room temperature. The resulting mixture was stirred for 3 h then diluted with MeOH (2 mL) and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 18-48% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford 6-[3-(5-chloro-2-methylpyridine-3- sulfonamido)-2,6-difluorophenyl]-N-methylimidazo[1,5-a]pyraz ine-1-carboxamide (79 mg, 40% yield) as a white solid. LCMS (ES, m/z): [M+H]+: 493 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.80 (s, 1H), 9.50 (d, J = 1.6 Hz, 1H), 8.77 (d, J = 2.4 Hz, 1H), 8.65 (s, 2H), 8.41 (t, J = 4.8 Hz, 1H), 8.08 (d, J = 2.4 Hz, 1H), 7.41 (td, J = 8.9, 5.8 Hz, 1H), 7.26 (t, J = 9.1 Hz, 1H), 2.84 (d, J = 4.8 Hz, 3H), 2.77 (s, 3H).

Example 109: Synthesis of 5-chloro-N-(2,4-difluoro-3-(1-(hydroxymethyl)imidazo[1,5- a]pyridin-6-yl)phenyl)-2-methoxypyridine-3-sulfonamide (Compound 94) Compound 94 Synthesis of 94-a: methyl 6-(3-((5-chloro-2-methoxypyridine)-3-sulfonamido)-2,6- difluorophenyl) imidazo[1,5-a]pyridine-1-carboxylate [0583] To a stirred solution of methyl 6-(3-amino-2,6-difluorophenyl)imidazo[1,5- a]pyridine-1-carboxylate (800 mg, 2.64 mmol, 1 equiv) in pyridine (10 mL) was added 5- chloro-2-methoxypyridine-3-sulfonyl chloride (958 mg, 4 mmol, 1.5 equiv) in portions at room temperature. The resulting mixture was stirred for 2 h, then concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 30-80% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford methyl 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]imidazo[1, 5-a]pyridine-1-carboxylate (810 mg, 60% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 509 Synthesis of Compound 94: 5-chloro-N-(2,4-difluoro-3-(1-(hydroxymethyl)imidazo[1,5- a]pyridin-6-yl)phenyl)-2-methoxypyridine-3-sulfonamide [0584] To a stirred solution of methyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyridine-1-carboxylate (200 mg, 0.39 mmol, 1 equiv) in THF (4 mL) was added LAH (23 mg, 0.59 mmol, 1.5 equiv) in portions at 0 °C. The resulting mixture was stirred for 2 h at room temperature. The reaction was quenched with H ₂ O and concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 35-75% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford 5-chloro-N-[2,4-difluoro-3- [1-(hydroxymethyl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-metho xypyridine-3-sulfonamide (50 mg, 26% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 481 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.42 (s, 1H), 8.50 (d, J = 2.7 Hz, 1H), 8.38 (d, J = 14.1 Hz, 2H), 8.08 (d, J = 2.7 Hz, 1H), 7.70 (d, J = 9.7 Hz, 1H), 7.35 (td, J = 9.1, 5.8 Hz, 1H), 7.22 (t, J = 9.5 Hz, 1H), 6.62 (d, J = 10.4 Hz, 1H), 5.00 (t, J = 5.6 Hz, 1H), 4.71 (d, J = 5.6 Hz, 2H), 3.92 (s, 3H).

Example 110: Synthesis of 5-chloro-N-[2,4-difluoro-3-[5-(1H-imidazol-2-yl)imidazo[1,5- b]pyridazin-2-yl]phenyl] -2-methylpyridine-3-sulfonamide (Compound 95) Synthesis of 95-a: 2-(6-chloropyridazin-3-yl)-2-[(diphenylmethylidene)amino]ace tonitrile [0585] To DMSO (340 mL) was added NaH (5.4 g, 134 mmol, 2 equiv, 60% in oil) in portions at 0 °C. To this was added 2-[(diphenylmethylidene)amino]acetonitrile (17.7 g, 80 mmol, 1.2 equiv) in DMSO (20 mL) dropwise at 0 °C. After 20 min, 3,6-dichloropyridazine (10 g, 67 mmol, 1 equiv) in DMSO (20 mL) was added at 0 °C and the resulting mixture was stirred in an ice bath for 1 hr. The reaction was quenched with water/ice (500 mL) and extracted with EA (3 x 500 mL). The combined organics were washed with brine (500 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The crude product 2- (6-chloropyridazin-3-yl)-2-[(diphenylmethylidene)amino]aceto nitrile was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 333 Synthesis of 95-b: 2-amino-2-(6-chloropyridazin-3-yl)acetonitrile [0586] To a stirred solution of 2-(6-chloropyridazin-3-yl)-2- [(diphenylmethylidene)amino]acetonitrile (20 g, crude) in THF (100 mL) was added 6 M HCl (100 mL). The resulting mixture was stirred for 3 h, then diluted with water (100 mL). The resulting mixture was extracted with DCM (3 x 200 mL) and the aqueous layer was basified to pH 8 with ammonia. The resulting mixture was extracted with DCM (3 x 200 mL). The combined organics were washed with brine (200 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. This resulted in 2-amino-2-(6- chloropyridazin-3-yl)acetonitrile (8.2 g, 71% yield over the 2 steps) as a brown solid, and which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 169 Synthesis of 95-c: 2-chloroimidazo[1,5-b]pyridazine-5-carbonitrile [0587] A solution of 2-amino-2-(6-chloropyridazin-3-yl)acetonitrile (8.2 g, 49 mmol, 1 equiv) in triethyl orthoformate (20 mL) was stirred for 3 h at 80 °C. The mixture was allowed to cool and was filtered, the filter cake being washed with Et ₂ O (2 x 10 mL). The filtrate was concentrated under reduced pressure to give 2-chloroimidazo[1,5-b]pyridazine-5-carbonitrile (5.8 g, 67% yield) as a brown solid and which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 179 Synthesis of 95-d: 2-(3-amino-2,6-difluorophenyl)imidazo[1,5-b]pyridazine- 5-carbonitrile [0588] To a stirred mixture of 2-chloroimidazo[1,5-b]pyridazine-5-carbonitrile (1 g, 5.6 mmol, 1 equiv) and 2,4-difluoro-3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (2 g, 8.4 mmol, 1.5 equiv) in dioxane (50 mL) and H ₂ O (10 mL) was added Pd(dtbpf)Cl ₂ (0.4 g, 0.6 mmol, 0.1 equiv) and K ₃ PO ₄ (2.4 g, 11 mmol, 2 equiv) at room temperature under N ₂ atmosphere. The resulting solution was stirred for 1 h at 90 °C in an oil bath then cooled and concentrated under vacuum. The crude product was re-crystallized from PE/EA (5/1, 20 mL) to afford 2-(3-amino-2,6-difluorophenyl)imidazo[1,5-b]pyridazine- 5-carbonitrile (1.5 g, 98%) as a yellow solid and which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 272 Synthesis of 95-e: 2,4-difluoro-3- [5-(1H-imidazol-2-yl)imidazo[1,5-b]pyridazin-2-yl]aniline [0589] Into a 50 mL round-bottom flask, was placed 2-(3-amino-2,6- difluorophenyl)imidazo[1,5-b]pyridazine-5-carbonitrile (1.5 g, 5.5 mmol, 1 equiv), MeOH (110 mL) and 30% MeONa in MeOH (2.5 g, 13.8 mmol, 2.5 equiv). The resulting solution was stirred for 3 h at 50 °C, then cooled to room temperature and 2,2-dimethoxyethanamine (0.9 g, 8.3 mmol, 1.5 equiv) and AcOH (1.2 g, 19 mmol, 3.5 equiv) were added. The resulting solution was stirred for 1 h at 50 °C, then cooled to room temperature.6 M HCl (10 mL) and MeOH (10 mL) were added and the mixture stirred for 3 h at 100 °C, before being concentrated. The resulting solution was diluted with 100 mL of water, and the pH adjusted to 8 with 30% NaOH. The solids formed were collected by filtration and dried to give 2,4- difluoro-3-[5-(1H-imidazol-2-yl)imidazo[1,5-b]pyridazin-2-yl ]aniline (1.2 g, 69% yield) as a brown solid and which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 313 Synthesis of 95-f: 2,4-difluoro-3-[5-(1-[[2-(trimethylsilyl)ethoxy] methyl]imidazol-2- yl)imidazo[1,5-b] pyridazin-2-yl]aniline [0590] To a stirred solution of 2,4-difluoro-3-[5-(1H-imidazol-2-yl)imidazo[1,5-b]pyridazin- 2-yl]aniline (170 mg, 0.5 mmol, 1 equiv) in THF (6 mL) was added NaH (0.3 g, 8.3 mmol, 2 equiv, 60%) in portions at 0 °C. SEMCl (1 g, 6 mmol, 1.5 equiv) was added dropwise at low temperature, and the resulting mixture stirred for 1 h in an ice bath. The reaction was quenched with water (100 mL), then extracted with EA (3 x 100 mL). The combined organics were washed with brine (3 x 100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/2) to afford 2,4-difluoro-3-[5-(1-[[2-(trimethylsilyl)ethoxy]methyl]imida zol-2- yl)imidazo[1,5-b]pyridazin-2-yl]aniline (1.2 g, 65% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 443 Synthesis of 95-g: 5-chloro-N-[2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-b]pyridazin-2-yl]phenyl]-2- methylpyridine-3-sulfonamide [0591] To a stirred solution of 2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-b]py ridazin-2-yl]aniline (120 mg, 0.3 mmol, 1 equiv) in pyridine (2 mL) was added 5-chloro-2-methylpyridine-3-sulfonyl chloride (230 mg, 0.8 mmol, 3 equiv, 80%) in portions at 0 °C. The resulting mixture was stirred for 2 h and concentrated under reduced pressure. The residue was purified by prep- HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-70% MeCN / 0.1% aqueous formic acid; Detector, 220 nm. This resulted in 5-chloro-N-[2,4-difluoro-3-[5-(1-[[2-(trimethylsilyl)ethoxy] methyl]imidazol-2- yl)imidazo[1,5-b]pyridazin-2-yl]phenyl]-2-methylpyridine-3-s ulfonamide (100 mg, 58% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 632 Synthesis of Compound 95: 5-chloro-N-[2,4-difluoro-3-[5-(1H-imidazol-2-yl)imidazo[1,5- b]pyridazin-2-yl]phenyl] -2-methylpyridine-3-sulfonamide [0592] Into a 50 mL round-bottom flask, was placed 5-chloro-N-[2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-b]pyridazin-2-yl]phenyl]-2- methylpyridine-3-sulfonamide (95 mg, 0.15 mmol, 1 equiv), DCM (6 mL) and TFA (2 mL). The resulting solution was stirred for 2 h and concentrated. The residue was dissolved in 3 mL of MeOH and the pH adjusted to 6 with NH ₃ in MeOH (7 mol/L). After concentration, the residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 5-35% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford 5-chloro-N-[2,4-difluoro-3-[5-(1H-imidazol-2-yl)imidazo [1,5-b]pyridazin-2-yl]phenyl]-2-methylpyridine-3-sulfonamide (50 mg, 66% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 502 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 11.88 (br s, 1H), 8.87 (s, 1H), 8.74 (d, J = 2.4 Hz, 1H), 8.69-8.55 (m, 1H), 8.08 (d, J = 2.4 Hz, 1H), 7.46 (td, J = 9.0, 5.9 Hz, 1H), 7.25 (td, J = 9.1, 1.6 Hz, 1H), 7.12 (s, 2H), 6.92 (dt, J = 9.4, 1.3 Hz, 1H), 2.78 (s, 3H). Example 111: Synthesis of (5S,6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)- 2,6-difluorophenyl]-N,5-dimethyl-5H,6H,7H,8H-imidazo[1,5-a]p yridine-1-carboxamide and (5R,6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,5- dimethyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (Compounds 96-1 & 96- 2) Synthesis of 96-a: 6-bromo-5-methylimidazo[1,5-a]pyridine-1-carboxylate [0593] To a stirred solution of 3-bromo-6-fluoro-2-methylpyridine (10 g, 52 mmol, 1 equiv) and methyl 2-isocyanoacetate (6.3 g, 63 mmol, 1.2 equiv) in DMF (100 mL) was added t- BuOK (105 mL, 63 mmol, 1.2 equiv, 1 M solution in THF) dropwise at room temperature. The resulting mixture was stirred for 1 h then water (300 mL) was added. The mixture was extracted with ethyl acetate (3 x 200 mL), and the combined organics were washed with brine (2 x 50 mL), dried over Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel (eluent: PE:EA = 4:1) to give methyl 6- bromo-5-methylimidazo[1,5-a]pyridine-1-carboxylate (5 g, 35% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 269, 271 Synthesis of 96-b: 6-(3-amino-2,6-difluorophenyl)-5-methylimidazo[1,5-a]pyridin e-1- carboxylate [0594] To a solution of methyl 6-bromo-5-methylimidazo[1,5-a]pyridine-1-carboxylate (5 g, 18 mmol, 1 equiv), 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) aniline (9.48 g, 37 mmol, 2 equiv) and Cs ₂ CO ₃ (12.1 g, 37 mmol, 2 equiv) in dioxane (50 mL) and H ₂ O (10 mL) were added SPhos (762 mg, 1.8 mmol, 0.1 equiv) and SPhos Pd G3 (1.4 g, 1.8 mmol, 0.1 equiv) at room temperature under nitrogen atmosphere. After stirring for 5 h at 90 °C, the resulting mixture was allowed to cool to room temperature and was diluted with water (50 mL), then extracted with EA (3 x 100 mL). The combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (2:1) to afford methyl 6-(3-amino-2,6-difluorophenyl)-5-methylimidazo[1,5-a]pyridin e-1-carboxylate (1.8 g, 31% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 318 Synthesis of 96-c: cis-methyl 6-(3-amino-2,6-difluorophenyl)-5-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxylate [0595] To a solution of methyl 6-(3-amino-2,6-difluorophenyl)-5-methylimidazo[1,5- a]pyridine-1-carboxylate (1 g, 3.1 mmol, 1 equiv) in MeOH (50 mL) was added Pd(OH) ₂ /C (335 mg, 20%) in a pressure tank. The mixture was hydrogenated at 80 °C under 30 atm of hydrogen pressure for 16 h, then filtered through a Celite pad and concentrated under reduced pressure. The residue was purified by Prep-HPLC to afford cis-methyl 6-(3-amino-2,6- difluorophenyl)-5-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine- 1-carboxylate (150 mg, 15% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 322 Synthesis of 96-d: cis-6-(3-amino-2,6-difluorophenyl)-N,5-dimethyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide [0596] A mixture of cis-methyl 6-(3-amino-2,6-difluorophenyl)-5-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxylate (200 mg) and CH ₃ NH ₂ solution in MeOH (5 mL, 2M) was stirred at 100 °C for 5 h. After being cooled to room temperature, the resulting solution was concentrated under reduced pressure to give cis-6-(3-amino-2,6-difluorophenyl)-N,5- dimethyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (160 mg, 80% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 321 Synthesis of Compounds 96-1 & 96-2: (5S,6R)-6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N,5-dimethyl-5H,6H,7H,8H-im idazo[1,5-a]pyridine-1- carboxamide and (5R,6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,5-dimethyl-5H,6H,7H,8H-imidazo[1,5-a]pyrid ine-1-carboxamide [0597] To a stirred solution of cis-6-(3-amino-2,6-difluorophenyl)-N,5-dimethyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (150 mg, 0.46 mmol, 1 equiv) and pyridine (111 mg, 1.4 mmol, 3 equiv) in DCM (5 mL) was added 5-chloro-2- methoxypyridine-3-sulfonyl chloride (170 mg, 0.7 mmol, 1.5 equiv) at room temperature. The reaction mixture was stirred for 1 h, then concentrated under reduced pressure to give a residue, which was purified by column chromatography over silica gel (eluent: PE:EA = 1:1) and chiral prep-HPLC with the following conditions: Column, CHIRALART, SB, 250x30 mm, 5 μm; Mobile Phase: 30% EtOH / Hexane to afford (5S,6R)-6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N,5-dimet hyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (Rt =11 min, 60 mg, 24% yield, cis stereochemistry randomly assigned) as a white solid and (5R,6S)-6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N,5-dimethyl-5H,6H,7H,8H-im idazo[1,5-a]pyridine-1- carboxamide (Rt = 15 mins, 60 mg, 24% yield, opposite cis stereochemistry assigned) as a white solid. (5S,6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,5- dimethyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide: LCMS (ES, m/z): [M+H] ⁺ : 526 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.32 (s, 1H), 8.51 (d, J = 2.6 Hz, 1H), 7.95 (d, J = 2.6 Hz, 1H), 7.72 (d, J = 4.8 Hz, 1H), 7.67 (s, 1H), 7.31 (td, J = 8.8, 5.8 Hz, 1H), 7.16-7.04 (m, 1H), 4.48-4.34 (m, 1H), 3.96 (s, 3H), 3.68-3.56 (m, 1H), 3.26 (s, 1H), 2.83 (ddd, J = 17.6, 11.6, 6.1 Hz, 1H), 2.71 (d, J = 4.7 Hz, 3H), 2.41-2.24 (m, 1H), 1.92 (d, J = 13.4 Hz, 1H), 1.00 (d, J = 6.6 Hz, 3H). (5R,6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N,5- dimethyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide: LCMS (ES, m/z): [M+H] ⁺ : 526 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.32 (s, 1H), 8.51 (d, J = 2.6 Hz, 1H), 7.95 (d, J = 2.6 Hz, 1H), 7.72 (d, J = 4.9 Hz, 1H), 7.67 (s, 1H), 7.30 (td, J = 8.8, 5.8 Hz, 1H), 7.16-7.05 (m, 1H), 4.51-4.37 (m, 1H), 3.96 (s, 3H), 3.68-3.58 (m, 1H), 3.25 (s, 1H), 2.83 (ddd, J = 17.6, 11.5, 5.9 Hz, 1H), 2.71 (d, J = 4.7 Hz, 3H), 2.44-2.26 (m, 1H), 1.92 (d, J = 13.5 Hz, 1H), 1.00 (d, J = 6.6 Hz, 3H). Example 112: Synthesis of 5-cyano-N-[2,4-difluoro-3-[5-(1H-imidazol- 2-yl)imidazo[1,5- b]pyridazin-2-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 97) Compound 97 Synthesis of 97-a: 5-cyano-N-[2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-b]pyridazin-2-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0598] To a stirred solution of 2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-b]py ridazin- 2-yl]aniline (120 mg, 0.3 mmol, 1 equiv) in pyridine (2 mL) was added 5-cyano-2-methoxypyridine-3-sulfonyl chloride (94 mg, 0.4 mmol, 1.5 equiv) in portions at room temperature. The resulting mixture was stirred for 2 h then concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-70% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford 5-cyano-N-[2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-b]py ridazin-2-yl]phenyl]-2- methoxypyridine-3-sulfonamide (105 mg, 61% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 639 Synthesis of Compound 97: 5-cyano-N-[2,4-difluoro-3-[5-(1H-imidazol- 2-yl)imidazo[1,5- b]pyridazin-2-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0599] Into a 50 mL round-bottom flask, was placed 5-cyano-N-[2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-b]pyridazin-2-yl]phenyl]-2- methoxypyridine-3-sulfonamide (100 mg, 0.16 mmol, 1 equiv), DCM (6 mL) and TFA (2 mL). The resulting solution was stirred for 2 h, then was concentrated. The residue was dissolved in 3 mL of MeOH and the pH adjusted to 8 with ammonia (7 M in MeOH). After concentration, the residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 5-35% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-cyano-N-[2,4-difluoro-3-[5-(1H-imidazol- 2-yl)imidazo[1,5-b]pyridazin-2-yl]phenyl]-2-methoxypyridine- 3-sulfonamide (50 mg, 63% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ :509 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.87 (d, J = 2.0 Hz, 2H), 8.64 (d, J = 9.4 Hz, 1H), 8.46 (d, J = 2.3 Hz, 1H), 7.46 (td, J = 9.1, 5.9 Hz, 1H), 7.25-7.15 (m, 1H), 7.12 (s, 2H), 6.94 (dt, J = 9.3, 1.2 Hz, 1H), 3.99 (s, 3H). Example 113: Synthesis of N-[2,4-difluoro-3-[5-(1H-imidazol-2-yl)imidazo[1,5- b]pyridazin- 2-yl]phenyl]-5-fluoro -2-methoxypyridine-3-sulfonamide (Compound 98) Compound 98 Synthesis of 98-a: N-[2,4-difluoro-3-[5-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo[1,5-b] pyridazin-2-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide [0600] To a stirred solution of 2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-b] pyridazin-2-yl]aniline (120 mg, 0.3 mmol, 1 equiv) in pyridine (2 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (92 mg, 0.4 mmol, 1.5 equiv) in portions at room temperature. The resulting mixture was stirred for 2 h then concentrated under reduced pressure. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-70% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford N-[2,4-difluoro-3-[5-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2- yl)imidazo[1,5-b]pyridazin-2-yl]phenyl]-5-fluoro-2-methoxypy ridine-3-sulfonamide (130 mg, 76% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 632 Synthesis of Compound 98: N-[2,4-difluoro-3-[5-(1H-imidazol-2-yl)imidazo[1,5-b]pyridaz in- 2-yl]phenyl]-5-fluoro -2-methoxypyridine-3-sulfonamide [0601] Into a 50 mL round-bottom flask was placed N-[2,4-difluoro-3-[5-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-b]py ridazin-2-yl]phenyl]-5-fluoro- 2-methoxypyridine-3-sulfonamide (125 mg, 0.2 mmol, 1 equiv), DCM (6 mL) and TFA (2 mL). The resulting solution was stirred for 2 h then concentrated. The residue was dissolved in 3 mL of MeOH and the pH adjusted to 8 with ammonia in MeOH (7 M) before it was concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 5-35% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give N-[2,4-difluoro-3-[5-(1H-imidazol-2- yl)imidazo[1,5-b]pyridazin- 2-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (50 mg, 50% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ :502 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.88 (s, 1H), 8.72-8.55 (m, 1H), 8.45 (d, J = 3.0 Hz, 1H), 8.03 (dd, J = 7.4, 3.0 Hz, 1H), 7.48 (td, J = 9.0, 5.9 Hz, 1H), 7.26 (t, J = 9.0 Hz, 1H), 7.12 (s, 2H), 6.94 (dt, J = 9.4, 1.3 Hz, 1H), 3.90 (s, 3H). Example 114: Synthesis of 5-chloro-N-(2,4-difluoro-3-(1-(isoxazol-5-yl)imidazo[1,5- a]pyridin-6-yl)phenyl)-2- methoxypyridine-3-sulfonamide (Compound 99)) Synthesis of 99-a: 6-bromoimidazo[1,5-a]pyridine-1-carboxylic acid [0602] To a stirred solution of methyl 6-bromoimidazo[1,5-a]pyridine-1-carboxylate (5 g, 19.6 mmol, 1 equiv) in THF (33 mL), MeOH (33 mL) and H ₂ O (33 mL) was added LiOH (2.5 g, 59 mmol, 3 equiv) and the reaction stirred at 40 °C for 3 h. The resulting solution was concentrated under vacuum to remove MeOH and THF, and the aqueous was acidified to pH 3 with 3 M HCl (20 mL). The precipitate was collected by filtration to afford 6- bromoimidazo[1,5-a]pyridine-1-carboxylic acid (4.5 g, 95% yield) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 241, 243 Synthesis of 99-b: 6-bromo-N-methoxy-N-methylimidazo[1,5-a]pyridine-1-carboxami de [0603] To a stirred solution of 6-bromoimidazo[1,5-a]pyridine-1-carboxylic acid (3.5 g, 14.5 mmol, 1 equiv) and methoxy(methyl)amine hydrochloride (2.8 g, 29 mmol, 2 equiv) in DMF (70 mL) was added HATU (6.6 g, 17.4 mmol, 1.2 equiv) and DIEA (5.6 g, 43.5 mmol, 3 equiv). The reaction was stirred at room temperature for 6 h, then diluted with H ₂ O (150 mL). This was extracted with EA (3 x 50 mL). The combined organics were washed with brine (2 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by trituration with H ₂ O (20 mL) and dried to afford pure 6-bromo-N- methoxy-N-methylimidazo[1,5-a]pyridine-1-carboxamide (3.5 g, 85% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 284, 286 Synthesis of 99-c: 1-(6-bromoimidazo[1,5-a]pyridin-1-yl)prop-2-yn-1-one [0604] To a stirred solution of 6-bromo-N-methoxy-N-methylimidazo[1,5-a]pyridine-1- carboxamide (600 mg, 2.1 mmol, 1 equiv) in THF (20 mL) was added bromo(ethynyl)magnesium (12.6 mL, 6.3 mmol, 3 equiv) dropwise at 0 °C under N ₂ atmosphere. The reaction was stirred at room temperature for 40 min, then quenched by addition of H ₂ O (10 mL). This was extracted with EA (3 x 10 mL), and the combined organics were washed with brine (5 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure, to give crude 1-[6-bromoimidazo[1,5-a]pyridin-1-yl]prop-2-yn-1-one (500 mg, crude) as a red solid. LCMS (ES, m/z): [M+H] ⁺ : 249, 251 Synthesis of 99-d: 3-(6-bromoimidazo[1,5-a]pyridin-1-yl)-3-oxopropanal oxime [0605] To a stirred solution of 1-[6-bromoimidazo[1,5-a]pyridin-1-yl]prop-2-yn-1-one (500 mg, 2 mmol, 1 equiv) in THF (10 mL) and H ₂ O (10 mL) was added Na ₂ CO ₃ (638 mg, 6 mmol, 3 equiv) and NH ₂ OH.HCl (279 mg, 4 mmol, 2 equiv). The reaction was stirred at room temperature overnight. The resulting mixture was extracted with EA (3 x 10 mL), and the combined organics were washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure to afford crude 1-[6-bromoimidazo[1,5-a]pyridin-1-yl]- 3-(N-hydroxyamino)prop-2-en-1-one (600 mg, crude) as a red solid. LCMS (ES, m/z): [M+H] ⁺ : 282, 284 Synthesis of 99-e: 5-(6-bromoimidazo[1,5-a]pyridin-1-yl)isoxazole [0606] To a stirred solution of 1-[6-bromoimidazo[1,5-a]pyridin-1-yl]-3-(N- hydroxyamino)prop-2-en-1-one (350 mg, 1.2 mmol, 1 equiv) in DCM (10 mL) was added gold (III) trichloride (19 mg, 0.062 mmol, 0.05 equiv). The reaction was stirred at room temperature overnight, then concentrated. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford 5-[6-bromoimidazo[1,5-a]pyridin-1-yl]- 1,2-oxazole (250 mg, 76% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 264, 266 Synthesis of 99-f: 2,4-difluoro-3-(1-(isoxazol-5-yl)imidazo[1,5-a]pyridin-6-yl) aniline [0607] To a stirred solution of 5-[6-bromoimidazo[1,5-a]pyridin-1-yl]-1,2-oxazole (500 mg, 1.9 mmol, 1 equiv) and 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) aniline (724 mg, 2.8 mmol, 1.5 equiv) in dioxane (15 mL) and H ₂ O (3 mL) were added K ₃ PO ₄ (804 mg, 3.8 mmol, 2 equiv) and Pd(dtbpf)Cl ₂ (123 mg, 0.19 mmol, 0.1 equiv). The reaction was stirred at 80 °C for 1 h under a nitrogen atmosphere, then cooled to room temperature and diluted with H ₂ O (5 mL). The mixture was extracted with EA (3 x 10 mL), and the combined organics were washed with brine (5 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford 2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin- 6-yl]aniline (400 mg, 67% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 313 Synthesis of Compound 99: 5-chloro-N-(2,4-difluoro-3-(1-(isoxazol-5-yl)imidazo[1,5- a]pyridin-6-yl)phenyl)-2- methoxypyridine-3-sulfonamide [0608] To a stirred solution of 2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin-6- yl]aniline (50 mg, 0.16 mmol, 1 equiv) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (46 mg, 0.19 mmol, 1.2 equiv) in DCM (5 mL) was added pyridine (38 mg, 0.48 mmol, 3 equiv). The reaction was stirred at room temperature overnight, then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 30-65% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford 5-chloro-N-(2,4-difluoro-3-(1-(isoxazol-5-yl)imidazo[1,5- a]pyridin-6-yl)phenyl)-2- methoxypyridine-3-sulfonamide (20 mg, 24% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 518 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.47 (s, 1H), 8.70-8.61 (m, 3H), 8.49 (d, J = 2.6 Hz, 1H), 8.14-8.02 (m, 2H), 7.38 (td, J = 8.9, 5.8 Hz, 1H), 7.29-7.19 (m, 1H), 7.06 (dd, J = 9.5, 1.6 Hz, 1H), 6.78 (d, J = 1.9 Hz, 1H), 3.92 (s, 3H). Example 115: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1-hydroxyethyl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 100) Synthesis of 100-a: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyridine-1-carboxylic acid [0609] To a stirred solution of methyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyridine-1-carboxylate (100 mg, 0.2 mmol, 1 equiv) in THF (2 mL) and MeOH (2 mL) was added a solution of LiOH (24 mg, 1 mmol, 5 equiv) in H ₂ O (1 mL). The resulting mixture was stirred for 2 h, then diluted with water (10 mL) and acidified to pH 3 with 1 M aqueous HCl. The resulting mixture was extracted with EA (3 x 10 mL). The combined organic layers were washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure to give 6-[3-(5-chloro-2-methoxypyridine- 3-sulfonamido)-2,6-difluorophenyl]imidazo[1,5-a] pyridine-1-carboxylic acid (80 mg, crude) as a yellow oil which was used in the next step directly without further purification LCMS (ES, m/z): [M+H] ⁺ : 495 Synthesis of 100-b: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]- N-methoxy-N-methylimidazo[1,5-a]pyridine-1-carboxamide [0610] Into a 50 mL round-bottom flask, was placed 6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]imidazo[1,5-a]pyridine-1-car boxylic acid (1 g, 2 mmol, 1 equiv), DMF (15 mL), methoxy(methyl)amine hydrochloride (394 mg, 4 mmol, 2 equiv), HATU (1.15 g, 3 mmol, 1.5 equiv) and DIEA (522 mg, 4 mmol, 2 equiv) at room temperature. The resulting solution was stirred for 2 h at room temperature, then diluted with 60 mL of H ₂ O and extracted with 3 x 20 mL of ethyl acetate. The combined organics were washed with 10 mL of brine, dried over anhydrous sodium sulfate, and concentrated under vacuum. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 30-80% MeCN / 0.1% aqueous formic acid to afford 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methoxy- N-methylimidazo[1,5-a]pyridine-1-carboxamide (730 mg, 67% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 538 Synthesis of 100-c: N-(3-[1-acetylimidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl )-5-chloro- 2-methoxypyridine-3-sulfonamide [0611] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methoxy-N-methylimidazo[1,5-a]pyridine-1-c arboxamide (500 mg, 0.9 mmol, 1 equiv) in THF (10 mL) was added methylmagnesium bromide (9 mL, 2.7 mmol, 3 equiv, 3 M in THF) at 0 °C. The resulting solution was stirred for 2 h at room temperature, then quenched with saturated aqueous NH ₄ Cl (20 mL) and extracted with 3 x 20 mL of ethyl acetate. The combined organics were washed with 10 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified by Flash-Prep- HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 30-80% MeCN / 0.1% aqueous formic acid; to afford N-(3-[1- acetylimidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl)-5-chlo ro-2-methoxypyridine-3- sulfonamide (300 mg, 65% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 493 Synthesis of Compound 100: 5-chloro-N-[2,4-difluoro-3-[1-(1-hydroxyethyl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0612] To a stirred solution of N-(3-[1-acetylimidazo[1,5-a]pyridin-6-yl]-2,4- difluorophenyl)-5-chloro-2-methoxypyridine-3-sulfonamide (80 mg, 0.2 mmol, 1 equiv) in MeOH (4 mL) was added NaBH ₄ (37 mg, 1 mmol, 6 equiv) in portions at room temperature. The resulting solution was stirred for 6 h then quenched by the addition of 5 mL of saturated aqueous NH ₄ Cl, and extracted with 4 x 5 mL of ethyl acetate. The combined organics were washed with 10 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 15-45% MeCN / 0.1% aqueous formic acid; to afford 5-chloro-N-[2,4-difluoro-3-[1-(1-hydroxyethyl)imidazo[1,5- a]pyridin-6-yl] phenyl]-2-methoxypyridine-3-sulfonamide (9.4 mg, 12% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 495 1H NMR (300 MHz, DMSO-d ₆ ) δ 10.42 (s, 1H), 8.50 (d, J = 2.6 Hz, 1H), 8.35 (d, J = 15.8 Hz, 2H), 8.07 (d, J = 2.6 Hz, 1H), 7.76 (d, J = 9.5 Hz, 1H), 7.34 (td, J = 8.9, 5.8 Hz, 1H), 7.21 (td, J = 9.1, 1.6 Hz, 1H), 6.62-6.52 (m, 1H), 5.14-5.01 (m, 2H), 3.92 (s, 3H), 1.49 (d, J = 6.1 Hz, 3H). Example 116: Synthesis of 6-(2-chloro-3-((5-chloro-2-methoxypyridine)-3-sulfonamido)- 6-fluorophenyl)-N- methylimidazo[1,5-a]pyridine-1-carboxamide (Compound 101) Synthesis of 101-a: methyl 6-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5-a]pyridine-1- carboxylate [0613] To a solution of 3-bromo-2-chloro-4-fluoroaniline (0.4 g, 1.8 mmol, 1 equiv) and methyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5-a ]pyridine-1-carboxylate (1 g, 3.2 mmol, 1.8 equiv) in dioxane (16 mL) and H ₂ O (4 mL) were added K ₂ CO ₃ (0.5 g, 3.6 mmol, 2 equiv) and Pd(dppf)Cl ₂ (0.13 g, 0.18 mmol, 0.1 equiv). The reaction was stirred at 80 °C for 1 h under a nitrogen atmosphere, then the resulting mixture was cooled, diluted with H ₂ O (10 mL) and extracted with EA (3 x 10 mL). The combined organics were washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE:EA (1:1) to afford methyl 6-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5-a]pyridine-1- carboxylate (450 mg, 79% yield) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 320 Synthesis of 101-b: 6-(3-amino-2-chloro-6-fluorophenyl)-N-methylimidazo[1,5-a]py ridine-1- carboxamide [0614] Methyl 6-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5-a]pyridine-1- carboxylate (400 mg, 1.2 mmol, 1 equiv) was dissolved in methylamine solution (30% in ethanol, 20 mL) and stirred at 80 °C overnight. The resulting solution was concentrated directly to afford crude 6-(3-amino-2-chloro-6-fluorophenyl)-N-methylimidazo[1,5-a]py ridine-1-carboxamide (380 mg, crude) as a red solid which was used for next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 319 Synthesis of Compound 101: 6-(2-chloro-3-((5-chloro-2-methoxypyridine)-3-sulfonamido)- 6-fluorophenyl)-N- methylimidazo[1,5-a]pyridine-1-carboxamide [0615] To a stirred solution of 6-(3-amino-2-chloro-6-fluorophenyl)-N-methylimidazo[1,5- a]pyridine-1-carboxamide (100 mg, 0.3 mmol, 1 equiv) in DCM (5 mL) was added 5-chloro- 2-methoxypyridine-3-sulfonyl chloride (91 mg, 0.37 mmol, 1.2 equiv) and pyridine (74 mg, 0.9 mmol, 3 equiv). The reaction was stirred at room temperature overnight. The resulting solution was concentrated and the residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 20-60% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford 6-[2-chloro-3-(5-chloro-2- methoxypyridine-3-sulfonamido)-6-fluorophenyl]-N-methylimida zo[1,5-a] pyridine-1- carboxamide (100 mg, 61% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 524 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.42 (s, 1H), 8.55 (d, J = 1.3 Hz, 1H), 8.50 (d, J = 2.6 Hz, 1H), 8.46 (s, 1H), 8.14 (d, J = 9.4 Hz, 1H), 8.10 (d, J = 4.9 Hz, 1H), 8.07 (d, J = 2.6 Hz, 1H), 7.52-7.35 (m, 2H), 6.96 (dt, J = 9.5, 1.0 Hz, 1H), 3.88 (s, 3H), 2.81 (d, J = 4.7 Hz, 3H). Example 117: Synthesis of 5-chloro-N-(2,4-difluoro-3-[1-[5-(trifluoromethyl)-4H-1,2,4- triazol-3-yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-2-methoxypyr idine-3-sulfonamide (Compound 102) Compound 102 Synthesis of 102-a: 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine-1-carbo nitrile [0616] Into a 40 mL vial were added 6-bromoimidazo[1,5-a]pyridine-1-carbonitrile (600 mg, 2.7 mmol, 1 equiv), 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) aniline (1.3 g, 5 mmol, 1.9 equiv), Pd(dtbpf)Cl ₂ (158 mg, 0.24 mmol, 0.1 equiv), K ₂ CO ₃ (1.1 g, 8 mmol, 3 equiv), dioxane (12 mL) and H ₂ O (2.4 mL). The resulting mixture was stirred for 2 h at 80 °C under nitrogen atmosphere, then was cooled and diluted with water (100 mL). The resulting mixture was extracted with EtOAc (3 x 100 mL), and the combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1:1) to afford 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a] pyridine-1-carbonitrile (570 mg, 78% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 271 Synthesis of 102-b: N-(3-[1-cyanoimidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl) -5-fluoro- 2-methoxypyridine-3-sulfonamide [0617] Into a 40 mL vial were added 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyridine- 1-carbonitrile (250 mg, 0.9 mmol, 1 equiv), 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (310 mg, 1.4 mmol, 1.5 equiv), DCM (5 mL) and pyridine (365 mg, 4.6 mmol, 5 equiv). The resulting mixture was stirred overnight at room temperature, then concentrated under vacuum. The residue was purified by silica gel column chromatography, eluting with PE/THF (2:1) to afford N-(3-[1-cyanoimidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl) -5-fluoro-2- methoxypyridine-3-sulfonamide (290 mg, 68% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 476 Synthesis of Compound 102: 5-chloro-N-(2,4-difluoro-3-[1-[5-(trifluoromethyl)-4H-1,2,4- triazol-3-yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-2-methoxypyr idine-3-sulfonamide [0618] Into a 50 mL round-bottom flask were added 5-chloro-N-(3-[1-cyanoimidazo[1,5- a]pyridin-6-yl]-2,4-difluorophenyl) -2-methoxypyridine-3-sulfonamide (200 mg, 0.42 mmol, 1 equiv), trifluoroethanimidamide hydrochloride (312 mg, 2.1 mmol, 5 equiv), Cu(AcO) ₂ (8 mg, 0.04 mmol, 0.1 equiv), Na ₂ CO ₃ (133 mg, 1.3 mmol, 3 equiv) and DMSO (4 mL). The resulting mixture was stirred for 4 h at 120 °C under O ₂ atmosphere. The mixture was allowed to cool and was diluted with water (100 mL). The resulting mixture was extracted with EtOAc (3 x 100 mL), and the combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 5-chloro- N-(2,4-difluoro-3-[1-[5-(trifluoromethyl)-4H-1,2,4-triazol-3 -yl]imidazo[1,5-a]pyridin-6- yl]phenyl)-2-methoxypyridine-3-sulfonamide (28 mg, 11% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 586 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 15.21 (s, 1H), 10.48 (s, 1H), 8.70 (s, 2H), 8.52 (d, J = 2.6 Hz, 1H), 8.19 (d, J = 9.4 Hz, 1H), 8.10 (d, J = 2.6 Hz, 1H), 7.40 (td, J = 8.8, 5.8 Hz, 1H), 7.33-7.22 (m, 1H), 7.16-7.07 (m, 1H), 3.93 (s, 3H).

Example 118: Synthesis of 5-chloro-N-[2-chloro-4-fluoro-3-[1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 103) Synthesis of 103-a: 2-chloro-4-fluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl] imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]aniline [0619] Into a 25 mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed 2-[6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)imidazo[1,5-a]pyridin-1-yl]-1-[[2-(trimethylsilyl)ethoxy] methyl] imidazole (200 mg, 0.45 mmol, 1 equiv), 3-bromo-2-chloro-4-fluoroaniline (102 mg, 0.45 mmol, 1 equiv), Pd(dppf)Cl ₂ (33 mg, 0.045 mmol, 0.1 equiv), K ₂ CO ₃ (188 mg, 1.36 mmol, 3 equiv), dioxane (10 mL) and H ₂ O (3 mL). The resulting solution was stirred for 2 h at 85 °C, then concentrated under vacuum. The residue was applied to a silica gel column eluting with THF:PE (1:1) to afford 2-chloro-4-fluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl] imidazol- 2-yl)imidazo[1,5-a]pyridin-6-yl]aniline (131 mg, 50% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 458 Synthesis of 103-b: 5-chloro-N-[2-chloro-4-fluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0620] Into a 25 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 2-chloro-4-fluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (131 mg, 0.29 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (69 mg, 0.29 mmol, 1 equiv) and pyridine (68 mg, 0.86 mmol, 3 equiv) in DCM (10 mL). The resulting solution was stirred for 2 h at 45 °C, then was concentrated under vacuum. The residue was applied onto a silica gel column, eluting with THF:PE (1:1) to give 5-chloro-N-[2-chloro-4-fluoro-3- [1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidaz o[1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (200 mg, 74% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 663 Synthesis of Compound 103: 5-chloro-N-[2-chloro-4-fluoro-3-[1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0621] Into a 25 mL 3-necked round-bottom flask was placed 5-chloro-N-[2-chloro-4-fluoro- 3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imid azo[1,5-a]pyridin-6-yl]phenyl]- 2-methoxypyridine-3-sulfonamide (200 mg, 0.3 mmol, 1 equiv) and TFA (3 mL). The resulting solution was stirred for 30 min at 50 °C then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 35-60% MeCN / 0.05% aqueous ammonia; detector, 220 nm; to give 5-chloro-N-[2-chloro-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo [1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (30 mg, 19% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 533 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.47 (dd, J = 6.3, 3.7 Hz, 3H), 8.22 (d, J = 9.4 Hz, 1H), 8.06 (d, J = 2.6 Hz, 1H), 7.50 – 7.30 (m, 2H), 7.07 (s, 2H), 6.79 (d, J = 9.4 Hz, 1H), 3.88 (s, 3H).

Example 119: Synthesis of 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl] phenyl]-2-methoxypyridine-3-sulfonamide (Compound 104) Synthesis of 104-a: 3-bromo-6-(bromomethyl)-2-fluoropyridine [0622] Into a 250 mL round-bottom flask were added 3-bromo-2-fluoro-6-methylpyridine (5 g, 26 mmol, 1 equiv) and CCl ₄ (100 mL) at room temperature. Benzoyl peroxide (0.67 g, 2.631 mmol, 0.1 equiv) and NBS (5.15 g, 29 mmol, 1.1 equiv) were added and the resulting mixture was stirred for 60 h at 60 °C under nitrogen atmosphere. The mixture was cooled, filtered and the filtrate was purified by silica gel column chromatography, eluting with PE/EtOAc (2:1) to afford 3-bromo-6-(bromomethyl)-2-fluoropyridine (7.1 g, crude) as a light orange oil. LCMS (ES, m/z): [M+H] ⁺ : 268, 270, 272 Synthesis of 104-b: 2-[(5-bromo-6-fluoropyridin-2-yl)methyl]isoindole-1,3-dione [0623] Into a 250 mL round-bottom flask were added 3-bromo-6-(bromomethyl)-2- fluoropyridine (13 g, 29 mmol, 1 equiv) and DMF (150 mL) at room temperature. Potassium phthalimide (8.29 g, 45 mmol, 1.5 equiv) was added and the resulting mixture was stirred for 2 h at 60 ^o C. The reaction was cooled and diluted with water (1000 mL), before being extracted with EA (3 x 300 mL). The combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (2/1) to afford 2-[(5- bromo-6-fluoropyridin-2-yl)methyl]isoindole-1,3-dione (7.5 g, 75% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 335, 337. Synthesis of 104-c: N-[(5-bromo-6-fluoropyridin-2-yl)methyl]formamide [0624] To a stirred solution of 2-[(5-bromo-6-fluoropyridin-2-yl)methyl]isoindole-1,3-dione (7.5 g, 22 mmol, 1 equiv) in i-PrOH (270 mL) and H ₂ O (45 mL) were added NaBH ₄ (4.2 g, 112 mmol, 5 equiv) in portions at 0 ^o C. The resulting mixture was stirred for 16 h, then HCOOH (63 mL) was added dropwise at room temperature. The resulting mixture was stirred for 24 h at 80 °C. After cooling, the reaction was filtered and the filtrate was concentrated under reduced pressure to give N-[(5-bromo-6-fluoropyridin-2-yl)methyl]formamide (12.6 g, crude) as a light brown oil. LCMS (ES, m/z): [M+H] ⁺ : 233, 235. Synthesis of 104-d: 6-bromo-5-fluoroimidazo[1,5-a]pyridine [0625] To a solution of N-[(5-bromo-6-fluoropyridin-2-yl)methyl]formamide (6 g, 14 mmol, 1 equiv) in toluene (240 mL) was added POCl ₃ (10.7 g, 70 mmol, 5 equiv) and the reaction stirred for 2 h at 100 °C. The mixture was cooled and concentrated under reduced pressure. The residue was diluted with EA (100 mL) and washed with 30 mL of aqueous NaHCO ₃ solution. The organics were washed with water and brine (1 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/1) to afford 6-bromo-5-fluoroimidazo[1,5- a]pyridine (1.1 g, 37% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 215, 217. Synthesis of 104-e: 6-bromo-5-fluoro-1-iodoimidazo[1,5-a]pyridine [0626] Into a 100 mL 3-necked round-bottom flask, was placed 6-bromo-5- fluoroimidazo[1,5-a]pyridine (2.1 g, 9.8 mmol, 1 equiv) in DMF (20 mL). NIS (2.2 g, 9.766 mmol, 1 equiv) was added at 0 °C, and the solution was stirred for 60 min at 0 °C in an ice/salt bath. The reaction was quenched with 200 mL of aqueous Na ₂ S ₂ O ₃ solution, and the solids were collected by filtration. Drying gave 6-bromo-5-fluoro-1-iodoimidazo[1,5- a]pyridine (2.4 g, 72% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 341, 343. Synthesis of 104-f: 2-[6-bromo-5-fluoroimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl] imidazole [0627] To a stirred solution of 1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole (1.4 g, 7 mmol, 3 equiv) in THF (10 mL) was added n-BuLi (2.8 mL, 7 mmol, 3 equiv, 2.5 M in hexane) dropwise at -78 °C under N ₂ atmosphere. The resulting mixture was stirred for 30 min then ZnCl ₂ (960 mg, 7.04 mmol, 3 equiv) was added at -78 °C. The resulting mixture was stirred for 30 min at room temperature, before 6-bromo-5-fluoro-1-iodoimidazo[1,5- a]pyridine (800 mg, 2.347 mmol, 1 equiv) and Pd(PPh ₃ ) ₄ (542 mg, 0.469 mmol, 0.2 equiv) in THF (5 mL) were added dropwise at room temperature. The resulting mixture was stirred for 30 min at 60 °C, then was cooled and quenched by the addition of water (30 mL). This was extracted with EA (3 x 30 mL), and the combined organics were washed with water (50 mL) and brine (50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (3/1) to afford 2-[6-bromo-5-fluoroimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (843 mg, 87% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 411, 413 Synthesis of 104-g: 2,4-difluoro-3-[5-fluoro-1-(1-[[2-(trimethylsilyl)ethoxy]met hyl]imidazol- 2-yl) imidazo[1,5-a]pyridin-6-yl]aniline [0628] To a solution of 2-[6-bromo-5-fluoroimidazo[1,5-a]pyridin-1-yl]-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (800 mg, 1.9 mmol, 1 equiv) and 2,4-difluoro-3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (992 mg, 3.9 mmol, 2 equiv) in dioxane (2 mL) and H ₂ O (0.2 mL) were added KF (3.4 g, 5.8 mmol, 3 equiv) and Pd(dtbpf)Cl ₂ (254 mg, 0.39 mmol, 0.2 equiv). After stirring for 16 h at 80 °C under a nitrogen atmosphere, the resulting mixture was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (50-100%) to afford 2,4-difluoro-3-[5- fluoro-1-(1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyridin-6- yl]aniline (460 mg, 51% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 460 Synthesis of 104-h: 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0629] To a stirred mixture of 2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (100 mg, 0.218 mmol, 1 equiv) in pyridine (1 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (105 mg, 0.435 mmol, 2 equiv) at room temperature. The resulting mixture was stirred for 30 min then diluted with water (20 mL). This was extracted with EA (3 x 20 mL), and the combined organics were washed with water (50 mL) and brine (50 mL), dried over anhydrous Na ₂ SO _4, then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/1) to afford 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (100 mg, 69% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 665. Synthesis of Compound 104: 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl] phenyl]-2-methoxypyridine-3-sulfonamide [0630] A solution of 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (90 mg, 0.135 mmol, 1 equiv) in DCM (1 mL) and TFA (0.5 mL) was stirred for 30 min at 40 °C. The mixture was cooled and concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Sunfire Prep C18 OBD, 50*250 mm 5 µm 10 nm; Mobile Phase: 5-45% 1:1 MeOH:ACN / 0.05% aqueous ammonia; Flow rate: 90 mL/min; to afford 5-chloro-N-[2,4- difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5-a]pyrid in-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (21 mg, 29% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 535. ¹ H NMR (300 MHz, DMSO-d6): δ 12.53 (br, 1H), 10.52 (br, 1H), 8.69 (s, 1H), 8.50 (d, J = 2.6 Hz, 1H), 8.17-8.04 (m, 2H), 7.53-7.39 (m, 1H), 7.27 (t, J = 9.1 Hz, 1H), 7.11 (s, 2H), 7.01-6.89 (m, 1H), 3.91 (s, 3H). Example 120: Synthesis of 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(2H-pyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]- 2-methoxypyridine-3-sulfonamide (Compound 105) Compound 105 Synthesis of 105-a: 5-[6-bromo-5-fluoroimidazo[1,5-a]pyridin-1-yl]-1-(oxan-2-yl) pyrazole [0631] A solution of 6-bromo-5-fluoro-1-iodoimidazo[1,5-a]pyridine (200 mg, 0.6 mmol, 1 equiv), 1-(oxan-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl )pyrazole (163 mg, 0.6 mmol, 1 equiv), K ₂ CO ₃ (162 mg, 1.2 mmol, 2 equiv) and Pd(dppf)Cl ₂ (43 mg, 0.06 mmol, 0.1 equiv) in dioxane (2 mL) and H ₂ O (0.4 mL) was stirred overnight at 60 °C under nitrogen atmosphere. The mixture was cooled and diluted with water (20 mL). The resulting mixture was extracted with EtOAc (3 x 50 mL), and the combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-30%) to afford 5-[6-bromo-5-fluoroimidazo[1,5-a]pyridin-1-yl]-1-(oxan-2-yl) pyrazole (170 mg, 79% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 365, 367. Synthesis of 105-b: 2,4-difluoro-3-[5-fluoro-1-[2-(oxan-2-yl)pyrazol-3-yl]imidaz o[1,5-a] pyridin-6-yl] aniline [0632] A solution of 5-[6-bromo-5-fluoroimidazo[1,5-a]pyridin-1-yl]-1-(oxan-2-yl) pyrazole (150 mg, 0.41 mmol, 1 equiv), 2,4-difluoro-3-(4,4,5-trimethyl-1,3,2-dioxaborolan-2- yl)aniline (198 mg, 0.82 mmol, 2 equiv), KF (72 mg, 1.24 mmol, 3 equiv) and Pd(dtbpf)Cl ₂ (81 mg, 0.12 mmol, 0.3 equiv) in dioxane (1.5 mL) and H ₂ O (0.3 mL) was stirred for 6 h at 80 °C under nitrogen atmosphere. The mixture was cooled and diluted with water (5 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL), and the combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-50%) to afford 2,4-difluoro-3-[5-fluoro-1-[2-(oxan-2-yl)pyrazol-3- yl]imidazo[1,5-a] pyridin-6-yl]aniline (100 mg, 59% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 414. Synthesis of 105-c: 5-chloro-N-(2,4-difluoro-3-[5-fluoro-1-[2-(oxan-2-yl)pyrazol -3- yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-2-methoxypyridine-3-su lfonamide [0633] To a stirred solution of 2,4-difluoro-3-[5-fluoro-1-[2-(oxan-2-yl)pyrazol-3- yl]imidazo[1,5-a]pyridin-6-yl]aniline (80 mg, 0.19 mmol, 1 equiv) in pyridine (1 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (70 mg, 0.29 mmol, 1.5 equiv) in portions at room temperature. The reaction was stirred for 2 h, then diluted with water (5 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL), and the combined organic layers were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-70%) to afford 5-chloro-N-(2,4-difluoro-3-[5-fluoro-1-[2-(oxan-2- yl)pyrazol-3-yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-2-methoxy pyridine-3-sulfonamide (80 mg, 67% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 619. Synthesis of Compound 105: 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(2H-pyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]- 2-methoxypyridine-3-sulfonamide [0634] To a stirred 5-chloro-N-(2,4-difluoro-3-[5-fluoro-1-[2-(oxan-2-yl)pyrazol -3- yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-2-methoxypyridine-3-su lfonamide (80 mg, 1 equiv) was added HCl in MeOH (1 mL, 4 M) dropwise at room temperature. The reaction was stirred for 2 h at room temperature and concentrated under vacuum. The residue was basified to pH 8 with saturated NaHCO ₃ (aq.) solution. The resulting mixture was extracted with EtOAc (3 x 50 mL), and the combined organic layers were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, Sunfire Prep C18 OBD, 50*250 mm, 5 µm, 10 nm; mobile phase: 15-50% MeCN / 0.1% aqueous formic acid; Detector, UV; to afford 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(2H-pyrazol-3- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (42 mg, 60% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 535. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.93 (s, 1H), 10.50 (s, 1H), 8.61 (s, 1H), 8.51 (d, J = 2.6 Hz, 1H), 8.08 (d, J = 2.6 Hz, 1H), 8.00 (d, J = 9.2 Hz, 1H), 7.78 (s, 1H), 7.54-7.40 (m, 1H), 7.29 (td, J = 9.1, 1.6 Hz, 1H), 6.88 (t, J = 8.1 Hz, 1H), 6.72 (d, J = 2.3 Hz, 1H), 3.91 (s, 3H). Example 121: Synthesis of : 6-[2-chloro-3-(5-chloro-2-methoxypyridine-3-sulfonamido)- 6-fluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 106) Synthesis of 106-a: 3-bromo-2-chloro-4-fluoroaniline [0635] Into a 250 mL round-bottom flask was placed 3-bromo-4-fluoroaniline (8 g, 42 mmol, 1 equiv), DMF (100 mL) and NCS (5.6 g, 42 mmol, 1 equiv). The resulting solution was stirred overnight at 60 °C in an oil bath. The reaction mixture was cooled and diluted with 200 mL of water, then extracted with 3 x 100 mL of ethyl acetate. The organics were washed with 200 ml of water and 200 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:10) to give 3-bromo-2-chloro-4-fluoroaniline (4.9 g, 52% yield) as a light brown solid. Synthesis of 106-b: 2-chloro-4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)aniline [0636] Into a 100 mL round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed 3-bromo-2-chloro-4-fluoroaniline (1 g, 4.5 mmol, 1 equiv), dioxane (40 mL), bis(pinacolato)diboron (1.36 g, 5.3 mmol, 1.2 equiv), KOAc (0.87 g, 8.9 mmol, 2 equiv), PCy ₃ (0.25 g, 0.9 mmol, 0.2 equiv) and Pd ₂ (dba) ₃ (0.41 g, 0.44 mmol, 0.1 equiv). The resulting solution was stirred for 16 h at 120 °C under nitrogen atmosphere. The reaction mixture was cooled and concentrated under vacuum. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:5) to give 2-chloro-4-fluoro-3-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (1 g) as a crude, light brown oil. LCMS (ES, m/z): [M+H] ⁺ : 272 Synthesis of 106-c: ethyl 6-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5-a]pyrazine-1- carboxylate [0637] Into a 40 mL vial purged and maintained with an inert atmosphere of nitrogen, was placed ethyl 6-bromoimidazo[1,5-a]pyrazine-1-carboxylate (280 mg, 1.0 mmol, 1 equiv), dioxane (10 mL), H ₂ O (2 mL), 2-chloro-4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)aniline (338 mg, 1.24 mmol, 1.2 equiv), K ₂ CO ₃ (287 mg, 2.07 mmol, 2 equiv) and Pd(dppf)Cl ₂ (76 mg, 0.1 mmol, 0.1 equiv). The reaction was stirred for 3 h at 80 °C under nitrogen atmosphere. The resulting mixture was concentrated under vacuum and the residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 10-80% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give ethyl 6-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5- a]pyrazine-1-carboxylate (100 mg, 29% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 335 Synthesis of 106-d: 6-(3-amino-2-chloro-6-fluorophenyl)-N-methylimidazo[1,5-a]py razine-1- carboxamide [0638] Into a 40 mL vial, was placed ethyl 6-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5- a]pyrazine-1-carboxylate (100 mg, 0.3 mmol, 1 equiv), MeOH (3 mL) and methylamine solution (30% in water, 0.5 mL). The reaction was stirred for 8 h at 50 °C in an oil bath, then concentrated under vacuum to give 6-(3-amino-2-chloro-6-fluorophenyl)-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (80 mg, crude) as a white solid which was used in the next step without further purification. LCMS (ES, m/z): [M+H] ⁺ : 320 Synthesis of Compound 106: 6-[2-chloro-3-(5-chloro-2-methoxypyridine-3-sulfonamido)-6- fluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide [0639] Into a 40 mL vial, was placed 6-(3-amino-2-chloro-6-fluorophenyl)-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (50 mg, 0.15 mmol, 1 equiv), pyridine (3 mL) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (56 mg, 0.23 mmol, 1.5 equiv). The resulting solution was stirred overnight and concentrated under reduced pressure. The residue was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 20-60% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 6-[2-chloro-3-(5-chloro-2-methoxypyridine-3-sulfonamido)-6-f luorophenyl]- N-methylimidazo[1,5-a]pyrazine-1-carboxamide (24 mg, 29% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 525 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.42 (s, 1H), 9.51 (d, J = 1.7 Hz, 1H), 8.63 (d, J = 1.7 Hz, 2H), 8.45 (dd, J = 19.7, 3.8 Hz, 2H), 8.07 (d, J = 2.6 Hz, 1H), 7.50 (dd, J = 9.0, 5.6 Hz, 1H), 7.39 (t, J = 8.8 Hz, 1H), 3.88 (s, 3H), 2.84 (d, J = 4.7 Hz, 3H). Example 122: Synthesis of N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5-fluoro-2-methoxypyridine-3-sulfonamide (Compound 107) Compound 107 Synthesis of 107-a: N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide [0640] To a stirred mixture of 2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6- yl]aniline (200 mg, 0.435 mmol, 1 equiv) in pyridine (2 mL) was added 5-fluoro-2- methoxypyridine-3-sulfonyl chloride (196 mg, 0.87 mmol, 2 equiv) at room temperature. The reaction was stirred for 30 min then diluted with water (20 mL). The resulting mixture was extracted with EA (3 x 20 mL), and the combined organics were washed with water (50 mL) and brine (50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/1) to afford N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2-(trimethylsilyl)ethoxy] methyl]imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3- sulfonamide (124 mg, 44% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 649. Synthesis of Compound 107: N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5-fluoro-2-methoxypyridine-3-sulfonamide [0641] A solution of N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (100 mg, 0.15 mmol, 1 equiv) in DCM (1 mL) and TFA (0.5 mL) was stirred for 30 min at 40 °C. The mixture was allowed to cool and was concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Sunfire Prep C18 OBD, 50*250 mm, 5 µm, 10 nm; Mobile Phase: 5-45% 1:1 MeOH:MeCN / 0.05% aqueous ammonia; Flow rate: 90 mL/min; to afford N-[2,4-difluoro-3- [5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phe nyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (47 mg, 59% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 519. ¹ H NMR (300 MHz, DMSO-d ₆ ): δ 12.51 (s, 1H), 10.45 (s, 1H), 8.69 (s, 1H), 8.44 (d, J = 3.0 Hz, 1H), 8.12 (d, J = 9.3 Hz, 1H), 8.01 (dd, J = 7.4, 3.0 Hz, 1H), 7.48-7.40 (m, 1H), 7.24 (t, J = 9.0 Hz, 1H), 7.14-7.08 (m, 2H), 6.95 (t, J = 8.2 Hz, 1H), 3.89 (s, 3H). Example 123: Synthesis of N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5-fluoro-2-methylpyridine-3-sulfonamide (Compound 108) Synthesis of 108-a: N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide [0642] To a stirred mixture of 2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (200 mg, 0.44 mmol, 1 equiv) in pyridine (2 mL) was added 5-fluoro-2-methylpyridine-3- sulfonyl chloride (182 mg, 0.87 mmol, 2 equiv) at room temperature. The reaction was stirred for 30 min at room temperature, then diluted with water (20 mL). The resulting mixture was extracted with EA (3 x 20 mL), and the combined organics were washed with water (50 mL) and brine (50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/1) to afford N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide (109 mg, 40% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 633. Synthesis of Compound 108: N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl] -5-fluoro-2-methylpyridine-3-sulfonamide [0643] A solution of N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-5-fluoro-2- methylpyridine-3-sulfonamide (85 mg, 0.13 mmol, 1 equiv) in DCM (1 mL) and TFA (0.5 mL) was stirred for 30 min at 40 °C. The mixture was allowed to cool and was concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Sunfire Prep C18 OBD, 50*250 mm, 5 µm, 10 nm; Mobile Phase: 5-45% 1:1 MeOH:ACN / 0.05% aqueous ammonia; Flow rate: 90 mL/min; to afford N-[2,4-difluoro-3- [5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phe nyl]-5-fluoro-2- methylpyridine-3-sulfonamide (48 mg, 71% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 503. ¹ H NMR (300 MHz, DMSO-d ₆ ): H NMR (300 MHz, DMSO-d ₆ ) δ 11.65 (br, 1H), 8.74-8.69 (m, 2H), 8.11 (d, J = 9.2 Hz, 1H), 7.93 (dt, J = 8.4, 1.9 Hz, 1H), 7.45 (q, J = 8.6 Hz, 1H), 7.28 (t, J = 9.1 Hz, 1H), 7.12 (s, 2H), 6.93 (t, J = 8.1 Hz, 1H), 2.78 (s, 3H). Example 124: Synthesis of 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridine -6-yl]phenyl]-2-methylpyridine-3-sulfonamide (Compound 109) Synthesis of 109-a: 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide [0644] To a stirred mixture of 2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]aniline (200 mg, 0.44 mmol, 1 equiv) in pyridine (2 mL) was added 5-chloro-2-methylpyridine-3-sulfonyl chloride (197 mg, 0.87 mmol, 2 equiv) at room temperature. The reaction was stirred for 30 min at room temperature, then diluted with water (20 mL). The resulting mixture was extracted with EA (3 x 20 mL), and the combined organic layers were washed with water (50 mL) and brine (50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/1) to afford 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (113 mg, 40% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 649. Synthesis of Compound 109: 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1H-imidazol-2- yl)imidazo[1,5-a]pyridine -6-yl]phenyl]-2-methylpyridine-3-sulfonamide [0645] A solution of 5-chloro-N-[2,4-difluoro-3-[5-fluoro-1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (90 mg, 0.139 mmol, 1 equiv) in DCM (1 mL) and TFA (0.5 mL) was stirred for 30 min at 40 °C. The mixture was cooled and concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Sunfire Prep C18 OBD, 50*250 mm, 5 µm, 10 nm; Mobile Phase: 5-45% 1:1 MeOH:MeCN / 0.05% aqueous ammonia; Flow rate: 90 mL/min; to afford 5-chloro-N-[2,4- difluoro-3-[5-fluoro-1-(1H-imidazol-2-yl)imidazo[1,5-a]pyrid in-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (58 mg, 81% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 519. ¹ H NMR (300 MHz, DMSO-d ₆ ): δ 11.87 (s, 1H), 8.75-8.74 (m, 1H), 8.69 (s, 1H), 8.13-8.06 (m, 2H), 7.44 (td, J = 9.0, 5.9 Hz, 1H), 7.33-7.20 (m, 1H), 7.12 (s, 2H), 6.93 (t, J = 8.2 Hz, 1H), 2.77 (s, 3H).

Example 125: Synthesis of N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]-2,4-difluorophenyl] -5-chloro-2-methoxypyridine-3-sulfonamide (Compound 110) Synthesis of 110-a: 6-(3-amino-2,6-difluorophenyl)-N-(2-aminophenyl)imidazo[1,5- a]pyrazine- 1-carboxamide [0646] Into a 40 mL vial were added 6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine- 1-carboxylic acid (1.2 g, 4.1 mmol, 1 equiv), HATU (1.73 g, 4.6 mmol, 1.1 equiv), DIEA (1.66 g, 13 mmol, 3 equiv) and DMF (12 mL). The resulting mixture was stirred for 30 min at room temperature. To a stirred solution of o-phenylenediamine (0.46 g, 0.45 mmol, 1 equiv) in DMF (12 mL) was added the activated acid solution, dropwise. The reaction was stirred for 2 h, then diluted with water (100 mL). The resulting mixture was extracted with EtOAc (3 x 100 mL), and the combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 6-(3-amino-2,6- difluorophenyl)-N-(2-aminophenyl)imidazo[1,5-a]pyrazine-1-ca rboxamide (840 mg, 53% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 381. Synthesis of 110-b: 3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl]-2, 4- difluoroaniline [0647] Into a 40 mL vial were added 6-(3-amino-2,6-difluorophenyl)-N-(2- aminophenyl)imidazo[1,5-a]pyrazine-1-carboxamide (830 mg, 2.2 mmol, 1 equiv) and AcOH (8 mL). The resulting mixture was stirred for 2 h at 80 °C, then cooled and diluted with water (200 mL). The precipitated solids were collected by filtration and washed with water (3 x 10 mL), then dried. This resulted in the mixture of 3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]-2,4-difluoroaniline and N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]-2,4-difluorophenyl]acetamide (710 mg) as an off-white solid. This was treated with 36% aqueous HCl (7 mL), stirring for 2 h at 100 °C. The resulting mixture was concentrated under vacuum and diluted with water (100 mL). The mixture was adjusted to pH 7 with saturated NaHCO ₃ (aq.) and extracted with EtOAc (3 x 100 mL). The combined organics were washed with brine (3 x 100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 3-[1-(1H-1,3-benzodiazol-2- yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluoroaniline (590 mg, 75% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 363. Synthesis of Compound 110: N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] - 2,4-difluorophenyl] -5-chloro-2-methoxypyridine-3-sulfonamide [0648] Into an 8 mL vial were added 3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin- 6-yl]-2,4-difluoroaniline (50 mg, 0.14 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3- sulfonyl chloride (66 mg, 0.27 mmol, 2 equiv) and pyridine (1 mL). The reaction was stirred for 2 h at room temperature, then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to give N-[3-[1-(1H-1,3-benzodiazol-2- yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluorophenyl]-5-chloro- 2-methoxypyridine-3- sulfonamide (24 mg, 31% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 568. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.05 (s, 1H), 10.47 (s, 1H), 9.77 (d, J = 1.6 Hz, 1H), 8.80 (s, 1H), 8.70 (d, J = 1.4 Hz, 1H), 8.52 (d, J = 2.5 Hz, 1H), 8.10 (d, J = 2.6 Hz, 1H), 7.76-7.63 (m, 1H), 7.61-7.35 (m, 2H), 7.33-7.14 (m, 3H), 3.94 (s, 3H). Example 126: Synthesis of N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]-2,4-difluorophenyl] -5-fluoro-2-methoxypyridine-3-sulfonamide (Compound 111) Synthesis of Compound 111: N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] - 2,4-difluorophenyl] -5-fluoro-2-methoxypyridine-3-sulfonamide [0649] Into an 8 mL vial were added 3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin- 6-yl]-2,4-difluoroaniline (60 mg, 0.17 mmol, 1 equiv), 5-fluoro-2-methoxypyridine-3- sulfonyl chloride (74 mg, 0.33 mmol, 2 equiv) and pyridine (1 mL). The resulting mixture was stirred for 2 h at room temperature and concentrated under reduced pressure. The solid was washed with DCM (5 mL), and the residue purified by silica gel column chromatography, eluting with PE/THF (1:1). This resulted in N-[3-[1-(1H-1,3-benzodiazol-2- yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluorophenyl]-5-fluoro- 2-methoxypyridine-3- sulfonamide (31 mg, 34% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 552. 1H NMR (300 MHz, DMSO-d ₆ ) δ 13.05 (s, 1H), 10.45 (s, 1H), 9.77 (s, 1H), 8.74 (d, J = 32.8 Hz, 2H), 8.47 (s, 1H), 8.13-7.95 (m, 1H), 7.78-7.65 (m, 1H), 7.63-7.34 (m, 2H), 7.31-7.16 (m, 3H), 3.93 (s, 3H).

Example 127: Synthesis of N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]-2,4-difluorophenyl] -5-cyano-2-methoxypyridine-3-sulfonamide (Compound 112) Synthesis of Compound 112: N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] - 2,4-difluorophenyl] -5-cyano-2-methoxypyridine-3-sulfonamide [0650] Into an 8 mL vial were added 3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin- 6-yl]-2,4-difluoroaniline (60 mg, 0.17 mmol, 1 equiv), 5-cyano-2-methoxypyridine-3- sulfonyl chloride (74 mg, 0.33 mmol, 2 equiv) and pyridine (1 mL). The resulting mixture was stirred for 2 h at room temperature, then concentrated under reduced pressure. The solid was washed with DCM (5 mL), and the residue purified by silica gel column chromatography, eluting with PE/THF (1:1). This resulted in N-[3-[1-(1H-1,3-benzodiazol-2- yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluorophenyl]-5-cyano-2 -methoxypyridine-3- sulfonamide (38 mg, 41% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 559. 1H NMR (300 MHz, DMSO-d ₆ ) δ 13.05 (s, 1H), 10.56 (s, 1H), 9.77 (d, J = 1.6 Hz, 1H), 8.94 (d, J = 2.2 Hz, 1H), 8.80 (s, 1H), 8.69 (s, 1H), 8.52 (d, J = 2.2 Hz, 1H), 7.71 (dd, J = 6.7 Hz, 1H), 7.60-7.36 (m, 2H), 7.35-7.13 (m, 3H), 4.04 (s, 3H). Example 128: Synthesis of N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]-2,4-difluorophenyl]-5-chloro-2-methylpyridine-3-sulfonam ide (Compound 113) Synthesis of Compound 113: N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]-2,4-difluorophenyl]-5-chloro-2-methylpyridine-3-sulfonam ide [0651] Into an 8 mL vial were added 3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin- 6-yl]-2,4-difluoroaniline (60 mg, 0.17 mmol, 1 equiv), 5-chloro-2-methylpyridine-3-sulfonyl chloride (74 mg, 0.33 mmol, 2 equiv) and pyridine (1 mL). The resulting mixture was stirred for 2 h at room temperature, then concentrated under reduced pressure. The solid was washed with DCM (5 mL) and the residue purified by silica gel column chromatography, eluting with PE/THF (1:1) to give N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] -2,4- difluorophenyl]-5-chloro-2-methylpyridine-3-sulfonamide (51 mg, 56% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 552. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.07 (1H, s), 10.82 (1H, s), 9.76 (1H, m), 8.81 (2H, m), 8.69 (1H, d), 8.10 (1H, d), 7.35-7.80 (3H, m), 7.16-7.34 (3H, m), 2.80 (3H, s). Example 129 : Synthesis of N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]-2,4-difluorophenyl]-5-fluoro-2-methylpyridine-3-sulfonam ide (Compound 114) Synthesis of Compound 114: N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] - 2,4-difluorophenyl]-5-fluoro-2-methylpyridine-3-sulfonamide [0652] Into an 8 mL vial were added 3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin- 6-yl]-2,4-difluoroaniline (60 mg, 0.17 mmol, 1 equiv), 5-fluoro-2-methylpyridine-3-sulfonyl chloride (69 mg, 0.33 mmol, 2 equiv) and pyridine (1 mL). The resulting mixture was stirred for 2 h at room temperature then concentrated under reduced pressure. The solid was washed with DCM (5 mL), and the residue purified by silica gel column chromatography, eluting with PE/THF (1:1) to give N-[3-[1-(1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyrazin-6-yl] - 2,4-difluorophenyl]-5-fluoro-2-methylpyridine-3-sulfonamide (45 mg, 51% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 536. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.05 (s, 1H), 10.81 (s, 1H), 9.76 (d, J = 1.6 Hz, 1H), 8.80 (s, 1H), 8.75 (d, J = 2.8 Hz, 1H), 8.68 (d, J = 1.6 Hz, 1H), 7.97 (dd, J = 8.2, 2.9 Hz, 1H), 7.78-7.64 (m, 1H), 7.59-7.48 (m, 1H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.33-7.15 (m, 3H), 2.80 (d, J = 1.2 Hz, 3H). Example 130: Synthesis of N-[3-[1-(4-chloro-1H-imidazol-2-yl)-5-fluoroimidazo[1,5- a]pyridin-6-yl]-2,4- difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (Compound 115) Synthesis of 115-a: 2-[6-bromo-5-fluoroimidazo[1,5-a]pyridin-1-yl]-4-chloro-1-[[ 2- (trimethylsilyl)ethoxy] methyl]imidazole [0653] To a stirred solution of 4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole (2.05 g, 8.8 mmol, 6 equiv) in THF (6 mL) was added 2.5 M n-BuLi in hexanes (3.5 mL, 8.8 mmol, 6 equiv) dropwise at -78 °C under N ₂ atmosphere. The resulting mixture was stirred for 30 min at low temperature, before 1 M ZnCl ₂ in Et ₂ O (8.8 mL, 8.8 mmol, 6 equiv) was added dropwise at -78 °C. The solution was stirred for 30 min at room temperature, then 6- bromo-5-fluoro-1-iodoimidazo[1,5-a]pyridine (500 mg, 1.46 mmol, 1 equiv) and Pd(PPh ₃ ) ₄ (339 mg, 0.29 mmol, 0.2 equiv) in THF (4 mL) were added dropwise. The reaction was stirred for 30 min at 60 °C, then cooled and quenched by the addition of water (30 mL). The resulting mixture was extracted with EA (3 x 30 mL), and the combined organics were washed with water (50 mL) and brine (50 mL), dried over anhydrous Na ₂ SO ₄ then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EA/PE (0-30%) to afford 2-[6-bromo-5-fluoroimidazo[1,5- a]pyridin-1-yl]-4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl ]imidazole (200 mg, 31% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 445, 447. Synthesis of 115-b: 3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol- 2-yl)-5- fluoroimidazo [1,5-a]pyridin-6-yl]-2,4-difluoroaniline [0654] A solution of 2-[6-bromo-5-fluoroimidazo[1,5-a]pyridin-1-yl]-4-chloro-1-[[ 2- (trimethylsilyl)ethoxy]methyl]imidazole (220 mg, 0.49 mol, 1 equiv), 2,4-difluoro-3-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (315 mg, 1.3 mmol, 2.5 equiv), KF (86 mg, 1.5 mmol, 3 equiv) and Pd(dtbpf)Cl ₂ (97 mg, 0.15 mmol, 0.3 equiv) in dioxane (2.2 mL) and H ₂ O (0.2 mL) was stirred for 6 h at 80 °C under nitrogen atmosphere. The mixture was cooled and diluted with water (5 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL), and the combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-50%) to afford 3-[1-(4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5-fluoroimidazo [1,5-a]pyridin-6-yl]-2,4- difluoroaniline (190 mg, 78% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 494. Synthesis of 115-c: N-[3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidaz ol-2-yl)-5- fluoroimidazo [1,5-a]pyridin-6-yl] -2,4-difluorophenyl]-5-fluoro-2-methoxypyridine-3- sulfonamide [0655] To a stirred solution of 3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol- 2-yl)-5-fluoroimidazo[1,5-a]pyridin-6-yl]-2,4-difluoroanilin e (80 mg, 0.16 mmol, 1 equiv) in pyridine (1 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (73 mg, 0.32 mmol, 2 equiv) in portions at room temperature. The reaction was stirred for 2 h at room temperature, then diluted with water (5 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL). The combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-50%) to afford N-[3-[1-(4- chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5- fluoroimidazo[1,5-a]pyridin-6- yl] -2,4-difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfonamid e (80 mg, 72% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 683. Synthesis of Compound 115: N-[3-[1-(4-chloro-1H-imidazol-2-yl)-5-fluoroimidazo[1,5- a]pyridin-6-yl]-2,4- difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide [0656] A solution of N-[3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidaz ol-2-yl)-5- fluoroimidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-5-fluo ro-2-methoxypyridine-3- sulfonamide (80 mg, 0.12 mmol, 1 equiv) in 1 M TBAF in THF (0.8 mL, 0.8 mmol, 6.8 equiv) was stirred overnight at 60 °C. The mixture was cooled and diluted with water (5 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL). The combined organics were washed with sat. NH ₄ Cl (aq.) and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, XBridge Prep C18 OBD, 5 µm, 19*150 mm; mobile phase: 16-39% MeCN / 0.05% aqueous ammonia; Detector, uv; to afford N-[3-[1-(4-chloro-1H-imidazol-2- yl)-5-fluoroimidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]- 5-fluoro-2-methoxypyridine-3- sulfonamide (16 mg, 25% yield) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 553. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.89 (s, 1H), 10.48 (s, 1H), 8.72 (s, 1H), 8.45 (d, J = 3.0 Hz, 1H), 8.08-7.96 (m, 2H), 7.52-7.38 (m, 1H), 7.25 (d, J = 6.8 Hz, 2H), 7.06-6.95 (m, 1H), 3.90 (s, 3H).

Example 131: Synthesis of 5-chloro-N-[3-[1-(4-chloro-1H-imidazol-2-yl)-5- fluoroimidazo[1,5-a]pyridin-6-yl]-2,4- difluoropheny]-2-methoxypyridine-3-sulfonamide (Compound 116) Synthesis of 116-a: 5-chloro-N-[3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]meth yl]imidazol- 2-yl)-5- fluoroimidazo[1,5-a]pyridine -6-yl]-2,4-difluorophenyl]-2-methoxypyridine-3- sulfonamide [0657] To a stirred solution of 3-[1-(4-chloro-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol2 - yl)-5-fluoroimidazo[1,5-a]pyridin-6-yl]-2,4-difluoroaniline (80 mg, 0.16 mmol, 1 equiv) in pyridine (1 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (79 mg, 0.32 mmol, 2 equiv) in portions at room temperature. The reaction was stirred for 2 h then diluted with water (5 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL). The combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-50%) to afford 5-chloro-N-[3-[1-(4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5-fluoroimidazo [1,5-a]pyridine-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide (75 mg, 66% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 699. Synthesis of Compound 116: 5-chloro-N-[3-[1-(4-chloro-1H-imidazol-2-yl)-5- fluoroimidazo[1,5-a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide [0658] A solution of 5-chloro-N-[3-[1-(4-chloro-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)-5-fluoroimidazo [1,5-a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide (80 mg, 0.11 mmol, 1 equiv) in TBAF (0.8 mL, 0.8 mmol, 7 equiv) was stirred overnight at 60 °C, then cooled and diluted with water (5 mL). The resulting mixture was extracted with EtOAc (3 x 20 mL). The combined organics were washed with sat. NH ₄ Cl (aq.) and brine, dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The crude product was purified by Prep-HPLC with the following conditions: Column, XBridge Prep C18 OBD, 5 µm, 19*150 mm; mobile phase: 19-40% MeCN / 0.05% aqueous ammonia; Detector, uv; to give 5-chloro-N-[3-[1-(4-chloro- 1H-imidazol-2-yl)-5-fluoroimidazo[1,5-a]pyridin-6-yl]-2,4-di fluorophenyl]-2- methoxypyridine-3-sulfonamide (7.6 mg, 12% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 569. 1H NMR (300 MHz, DMSO-d ₆ ) δ 12.90 (s, 1H), 10.51 (s, 1H), 8.72 (s, 1H), 8.51 (d, J = 2.6 Hz, 1H), 8.11-7.99 (m, 2H), 7.54-7.40 (m, 1H), 7.35-7.21 (m, 2H), 7.07-6.95 (m, 1H), 3.91 (s, 3H). Example 132: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2-cyano-6- fluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 117) Synthesis of 117-a: ethyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5- a]pyrazine-1-carboxylate [0659] Into a 25 mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed ethyl 6-bromoimidazo[1,5-a]pyrazine-1-carboxylate (300 mg, 1 mmol, 1 equiv), dioxane (10 mL), bis(pinacolato)diboron (423 mg, 1.7 mmol, 1.5 equiv), Pd(dppf)Cl ₂ (81.3 mg, 0.1 mmol, 0.1 equiv) and KOAc (327 mg, 3.3 mmol, 3 equiv). The resulting solution was stirred for 4 h at 90 °C in an oil bath. This solution was used directly in next step. Synthesis of 117-b: ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2-cyano-6- fluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylate [0660] To the solution from step 1 was added N-(3-bromo-2-cyano-4-fluorophenyl)-5- chloro-2-methoxypyridine-3-sulfonamide (300 mg, 0.72 mmol, 1 equiv), Pd(dtbpf)Cl ₂ (47 mg, 0.07 mmol, 0.1 equiv), K ₂ CO ₃ (296 mg, 2.16 mmol, 3 equiv and H ₂ O (3 mL). The resulting solution was stirred for 4 h at 85 °C, then concentrated under vacuum. The residue was applied to a silica gel column, eluting with dichloromethane/methanol (10:1) to give ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2-cyano-6- fluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylate (150 mg) as a white solid. Synthesis of Compound 117: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2-cyano-6- fluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide [0661] Into a 25 mL 3-necked round-bottom flask, was placed 30% CH ₃ NH ₂ /H ₂ O (2 mL), THF (5 mL) and ethyl 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2-cyano-6- fluorophenyl]imidazo [1,5-a]pyrazine-1-carboxylate (150 mg, 0.28 mmol, 1 equiv). The resulting solution was stirred for 2 h at 50 °C then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, Sunfire Prep C18 OBD, 50*250 mm 5 µm 10 nm, Mobile Phase: 5-30% MeCN / 0.05% aqueous ammonia; Detector, 220 nm; to give 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2- cyano-6-fluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carbo xamide (2 mg) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 516 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.87 (br s, 1H), 9.53 (d, J = 1.7 Hz, 1H), 8.71 (d, J = 16.3 Hz, 1H), 8.44 (d, J = 4.9 Hz, 1H), 8.36-8.20 (m, 1H), 8.18-8.08 (m, 1H), 8.05 (d, J = 2.6 Hz, 1H), 7.52- 7.30 (m, 2H), 3.86 (s, 3H), 2.82 (d, J = 4.8 Hz, 3H). Example 133: Synthesis of N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin- 6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (Compound 118) Synthesis of Compound 118: N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin- 6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide [0662] To a stirred solution of 2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin-6- yl]aniline (100 mg, 0.32 mmol, 1 equiv) and pyridine (76 mg, 0.96 mmol, 3 equiv) in DCM (5 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (108 mg, 0.48 mmol, 1.5 equiv) at room temperature. The reaction was stirred for 1 h at room temperature, then concentrated under reduced pressure. The residue was purified by prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 10-40% MeCN / 0.05% aqueous ammonia; Detector, 220 nm; to afford N-[2,4-difluoro-3-[1-(1,2- oxazol-5-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-me thoxypyridine-3-sulfonamide (30 mg, 19% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 502 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.46 (s, 1H), 8.69-8.62 (m, 3H), 8.48 (d, J = 3.0 Hz, 1H), 8.12-7.97 (m, 2H), 7.38 (td, J = 8.9, 6.0 Hz, 1H), 7.30-7.21 (m, 1H), 7.06 (dd, J = 9.5, 1.5 Hz, 1H), 6.78 (d, J = 2.0 Hz, 1H), 3.92 (s, 3H).

Example 134: Synthesis of 5-cyano-N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 119) Synthesis of Compound 119: 5-cyano-N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0663] To a stirred solution of 2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin-6- yl]aniline (100 mg, 0.32 mmol, 1 equiv) and pyridine (76 mg, 0.96 mmol, 3 equiv) in DCM (5 mL) was added 5-cyano-2-methoxypyridine-3-sulfonyl chloride (111 mg, 0.48 mmol, 1.5 equiv). The resulting mixture was stirred for 1 h then concentrated under reduced pressure. The residue was purified by prep-HPLC with following conditions: Column, Welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 5-40% MeCN / 0.05% aqueous ammonia; Detector, 220 nm; to afford 5-cyano-N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (30 mg, 18% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 509 1H NMR (300 MHz, DMSO-d ₆ ) δ 10.56 (s, 1H), 8.95 (d, J = 2.2 Hz, 1H), 8.70-8.58 (m, 3H), 8.52 (d, J = 2.2 Hz, 1H), 8.07 (d, J = 9.5 Hz, 1H), 7.40 (td, J = 9.0, 5.9 Hz, 1H), 7.27 (td, J = 9.2, 1.5 Hz, 1H), 7.11-6.99 (m, 1H), 6.78 (d, J = 1.9 Hz, 1H), 4.03 (s, 3H).

Example 135: Synthesis of 2-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[4,3-b][1,3]thiazole-7-carbox amide (Compound 120) Synthesis of 120-a: methyl 2-bromoimidazo[4,3-b][1,3]thiazole-7-carboxylate [0664] To a solution of methyl 2-isocyanoacetate (0.82 g, 8 mmol, 2 equiv) in DMF was added sodium hydride (0.2 g, 8 mmol, 2 equiv) at -20 °C. The mixture was stirred for 15 min. 2,5-Dibromothiazole (1 g, 4 mmol, 1 equiv) was added and the mixture was allowed to warm to RT and stirred for 3 h. The reaction was quenched by the addition of water/ice (50 mL) at 0 °C, then extracted with EtOAc (3 x 25 mL). The combined organics were washed with brine (2x20 mL), dried over anhydrous Na ₂ SO ₄ , and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford methyl 2-bromoimidazo[4,3-b][1,3]thiazole-7-carboxylate (500 mg, 47% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 261, 263 Synthesis of 120-b: methyl 2-(3-amino-2,6-difluorophenyl)imidazo[4,3-b][1,3]thiazole-7- carboxylate [0665] To a solution of methyl 2-bromoimidazo[4,3-b][1,3]thiazole-7-carboxylate (580 mg, 2.2 mmol, 1 equiv) and 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) aniline (850 mg, 3 mmol, 1.5 equiv) in dioxane (50 mL) and H ₂ O (10 mL) were added K ₃ PO ₄ (943 mg, 4.4 mmol, 2 equiv) and Pd(dtbpf)Cl ₂ (145 mg, 0.2 mmol, 0.1 equiv). After stirring for 1 h at 90 °C under a nitrogen atmosphere, the resulting mixture was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (5:1) to afford methyl 2-(3-amino-2,6-difluorophenyl)imidazo[4,3-b][1,3]thiazole- 7-carboxylate (550 mg, 80% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 310 Synthesis of 120-c: 2-(3-amino-2,6-difluorophenyl)-N-methylimidazo[4,3-b][1,3]th iazole-7- carboxamide [0666] A solution of methyl 2-(3-amino-2,6-difluorophenyl)imidazo[4,3-b][1,3]thiazole-7- carboxylate (550 mg, 1.8 mmol, 1 equiv) and 40% methylamine water solution (5 mL) in THF (5 mL) was stirred for 16 h at 40°C. The resulting mixture was concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20-85% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 2-(3-amino-2,6-difluorophenyl)-N- methylimidazo[4,3-b][1,3]thiazole-7-carboxamide (300 mg, 55% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 309 Synthesis of Compound 120: 2-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[4,3-b][1,3]thiazole-7-carbox amide [0667] To a stirred solution of 2-(3-amino-2,6-difluorophenyl)-N-methylimidazo[4,3- b][1,3]thiazole-7-carboxamide (150 mg, 0.49 mmol, 1 equiv) in pyridine (2 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (141 mg, 0.59 mmol, 1.2 equiv) dropwise. The resulting mixture was stirred for 3 h then concentrated. The residue was purified by prep- HPLC with the following conditions: Column: welch Vltimate XB-C18, 50x250 mm, 10 µm; Mobile Phase: 20-60% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 2-[3-(5- chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]- N-methylimidazo[4,3- b][1,3]thiazole-7-carboxamide (150 mg) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 514 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.54 (s, 1H), 8.52 (d, J = 2.6 Hz, 1H), 8.41 (s, 1H), 8.33 (s, 1H), 8.07 (dd, J = 9.8, 3.7 Hz, 2H), 7.42 (td, J = 8.9, 5.8 Hz, 1H), 7.31 (ddd, J = 10.5, 9.0, 1.5 Hz, 1H), 3.92 (s, 3H), 2.77 (d, J = 4.7 Hz, 3H). Example 136: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide (Compound 121) Synthesis of Compound 121: 5-chloro-N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide [0668] To a stirred solution of 2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin-6- yl]aniline (100 mg, 0.32 mmol, 1 equiv) and pyridine (76 mg, 0.96 mmol, 3 equiv) in DCM (5 mL) was added 5-chloro-2-methylpyridine-3-sulfonyl chloride (109 mg, 0.48 mmol, 1.5 equiv) at room temperature. The resulting mixture was stirred for 2 h at room temperature then concentrated under reduced pressure. The residue was purified by prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 2-47% MeCN / 0.05% aqueous ammonia; Detector, 220 nm; to afford 5-chloro-N-[2,4- difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin-6-yl]ph enyl]-2-methylpyridine-3- sulfonamide (20 mg, 13% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 502 ¹ H NMR (300 MHz, Methanol-d ₄ ) δ 8.64 (d, J = 2.4 Hz, 1H), 8.54 (s, 1H), 8.46 (dd, J = 4.9, 1.7 Hz, 2H), 8.17 (d, J = 2.4 Hz, 1H), 8.11 (d, J = 9.5 Hz, 1H), 7.53 (td, J = 9.0, 5.7 Hz, 1H), 7.15 (td, J = 9.2, 1.8 Hz, 1H), 7.09-7.02 (m, 1H), 6.75 (d, J = 2.0 Hz, 1H), 2.85 (s, 3H).

Example 137: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-6-fluoro-2- methylphenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxamide (Compound 122) Synthesis of 122-a: 2-bromo-1-fluoro-3-methyl-4-nitrobenzene [0669] To a stirred solution of 2-bromo-1-fluoro-3-methylbenzene (5 g, 26.4 mmol, 1 equiv) in H ₂ SO ₄ (66 mL) was added HNO ₃ (3.3 g, 52 mmol, 2 equiv) dropwise at 0 °C under nitrogen atmosphere. The reaction was stirred for 30 min, then diluted with water (100 mL). The resulting mixture was extracted with EtOAc (2 x 50 mL), and the combined organics were washed with brine (1 x 50 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (50:1) to afford 2-bromo-1-fluoro-3-methyl-4-nitrobenzene (2 g, 32% yield) as an off-white solid. Synthesis of 122-b: 3-bromo-4-fluoro-2-methylaniline [0670] To a solution of 2-bromo-1-fluoro-3-methyl-4-nitrobenzene (1 g, 4.3 mmol, 1 equiv) in 10 mL THF was added Pd/C (10%, 200 mg) in a pressure tank. The mixture was hydrogenated at 40 °C under 2 atm hydrogen pressure for 3 h, filtered through a Celite pad and concentrated under reduced pressure to give 3-bromo-4-fluoro-2-methylaniline (500 mg, 57% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 204, 206 Synthesis of 122-c: 6-(3-amino-6-fluoro-2-methylphenyl)imidazo[1,5-a]pyridine-1- carboxylate [0671] To a solution of methyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,5- a]pyridine-1-carboxylate (550 mg, 1.8 mmol, 1 equiv) and 3-bromo-4-fluoro-2-methylaniline (557 mg, 2.7 mmol, 1.5 equiv) in dioxane (10 mL) were added K ₃ PO ₄ (772 mg, 3.6 mmol, 2 equiv) and Pd(dtbpf)Cl ₂ (118 mg, 0.18 mmol, 0.1 equiv). After stirring for 3 h at 90 °C under a nitrogen atmosphere, the resulting mixture was concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:8) to afford methyl 6-(3-amino-6-fluoro-2-methylphenyl)imidazo[1,5-a]pyridine-1- carboxylate (400 mg, 73% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 300 Synthesis of 122-d: 6-(3-amino-6-fluoro-2-methylphenyl)-N-methylimidazo[1,5-a]py ridine- 1-carboxamide [0672] To a stirred mixture of methyl 6-(3-amino-6-fluoro-2-methylphenyl)imidazo[1,5- a]pyridine-1-carboxylate (200 mg, 0.67 mmol, 1 equiv) in THF (5 mL) was added 40% aqueous methylamine solution (5 mL) dropwise at room temperature. The resulting mixture was stirred for 16 h at room temperature then concentrated under reduced pressure. The residue was purified by reverse flash chromatography with the following conditions: column, C18 silica gel; mobile phase: 15-75% MeOH / water; detector, UV 254 nm to give 6-(3- amino-6-fluoro-2-methylphenyl)-N-methylimidazo[1,5-a]pyridin e-1-carboxamide (180 mg, 90% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 299 Synthesis of Compound 122: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-6-fluoro-2- methylphenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxamide [0673] To a stirred solution of 6-(3-amino-6-fluoro-2-methylphenyl)-N-methylimidazo[1,5- a]pyridine-1-carboxamide (80 mg, 0.3 mmol, 1 equiv) in pyridine (2 mL) was added 5- chloro-2-methoxypyridine-3-sulfonyl chloride (78 mg, 0.36 mmol, 1.2 equiv) in DCM (2 mL) dropwise at room temperature . The reaction was stirred for 2 h then concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 25-65% MeCN / 0.1% aqueous formic acid; detector, 220 nm; to give 6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-6-fluoro-2-methylphenyl]-N-methylimidazo[1,5-a] pyridine-1-carboxamide (30 mg, 22% yield) as a white solid LCMS (ES, m/z): [M+H] ⁺ : 504 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.04 (s, 1H), 8.53 (d, J = 2.6 Hz, 1H), 8.49-8.39 (m, 2H), 8.13 (d, J = 9.3 Hz, 1H), 8.06 (dd, J = 13.6, 3.7 Hz, 2H), 7.15 (t, J = 8.8 Hz, 1H), 7.07 (dd, J = 8.9, 5.5 Hz, 1H), 6.98-6.88 (m, 1H), 3.97 (s, 3H), 2.81 (d, J = 4.7 Hz, 3H), 2.06 (d, J = 10.5 Hz, 3H). Example 138: Synthesis of 5-cyano-N-[2,4-difluoro-3-[1-(4,5,6,7-tetrahydro-1H-1,3- benzodiazol-2-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (Compound 123) Synthesis of 123-a: 1-[[2-(trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro-1,3- benzodiazole [0674] Into a 100 mL 3-necked round-bottom flask were added 4,5,6,7-tetrahydro-1H-1,3- benzodiazole (500 mg, 4.1 mmol, 1 equiv) in DMF (5 mL).60% NaH in oil (294 mg, 12.2 mmol, 3 equiv) was added in portions at 0 °C, and the resulting mixture was stirred for 30 min in the ice bath. To this was added [2-(chloromethoxy)ethyl]trimethylsilane (682 mg, 4.1 mmol, 1 equiv) dropwise at 0 °C. The reaction was stirred for 2 h at room temperature, then was quenched with water (100 mL). The resulting mixture was extracted with EtOAc (3 x 100 mL), and the combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 1-[[2- (trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro-1,3-benzod iazole (800 mg, 77% yield) as a colorless oil. LCMS (ES, m/z): [M+H] ⁺ : 253. Synthesis of 123-b: 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]-4,5, 6,7- tetrahydro-1,3- benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]aniline [0675] Into a 40 mL vial was added 1-[[2-(trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro- 1,3-benzodiazole (408 mg, 1.6 mmol, 3 equiv) in THF (5 mL). To this was added 2.5M n- BuLi in hexanes (0.7 mL, 1.6 mmol, 3 equiv) dropwise at -78 °C. The resulting mixture was stirred for 1 h at -78 °C, before 1 M ZnCl ₂ in ether solution (1.6 mL, 1.6 mmol, 1 equiv) was added. This was stirred for 1 h to room temperature, then 2,4-difluoro-3-[1-iodoimidazo[1,5- a]pyridin-6-yl]aniline (200 mg, 0.54 mmol, 1 equiv), Pd(PPh ₃ ) ₄ (62 mg, 0.054 mmol, 0.1 equiv) were added. The reaction was stirred for 1 h at 60 °C, then was cooled and diluted with water (100 mL). The resulting mixture was extracted with EtOAc (3 x 100 mL). The combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro-1,3-benzod iazol-2-yl)imidazo[1,5a]pyridin- 6-yl]aniline (120 mg, 33% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 496. Synthesis of 123-c: 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]m ethyl]- 4,5,6,7-tetrahydro- 1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0676] Into an 8 mL vial were added 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]- 4,5,6,7-tetrahydro-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridi n-6-yl]aniline (200 mg, 0.4 mmol, 1 equiv), 5-cyano-2-methoxypyridine-3-sulfonyl chloride (188 mg, 0.81 mmol, 2 equiv) and pyridine (1 mL). The resulting mixture was stirred for 2 h at room temperature, then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro-1,3-benzod iazol-2-yl)imidazo [1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (210 mg, 58% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 692. Synthesis of Compound 123: 5-cyano-N-[2,4-difluoro-3-[1-(4,5,6,7-tetrahydro-1H-1,3- benzodiazol-2-yl)imidazo [1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide [0677] Into an 8 mL vial were added 5-cyano-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro-1,3-benzod iazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (190 mg, 0.28 mmol, 1 equiv) and TFA (5 mL). The resulting mixture was stirred for 30 min at 40 °C, then cooled and concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: Sunfire Prep C18 OBD, 50*250 mm 5 µm 10 nm; Mobile Phase: 18-48% MeCN / 0.1% aqueous formic acid; Flow rate: 90 mL/min; detector 220 nm; to afford 5-cyano-N-[2,4-difluoro-3-[1-(4,5,6,7-tetrahydro-1H-1,3-benz odiazol-2- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (24 mg, 16% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 562. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.94 (1H, s), 8.48-8.60 (3H, m), 8.21 (1H, d), 7.20-7.45 (2H, m), 6.88 (1H, d), 4.04 (3H, s), 2.57 (4H, m), 1.80 (4H, m).

Example 139: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 124) Synthesis of 124-a: 2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy]met hyl]-1,2,4- triazol-3-yl)imidazo[1,5-a]pyrazin-6-yl]aniline [0678] To a solution of 3-methyl-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazole (2 g, 9.4 mmol, 5 equiv) in THF (20 mL) was added dropwise n-butyllithium solution (2.5 M in THF, 3.75 mL, 9.4 mmol) at -78 °C under N ₂ atmosphere. The reaction mixture was stirred at -78 °C for 30 min, then a solution of ZnCl ₂ (1.0 M in Et ₂ O, 9.4 mL, 9.4 mmol) was added dropwise and the mixture was stirred for 30 min at room temperature. A solution of Pd(PPh ₃ ) ₄ (434 mg, 0.38 mmol, 0.2 equiv) and 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyrazin- 6-yl]aniline (700 mg, 1.88 mmol, 1 equiv) in THF (2 mL) was then added dropwise and the mixture was stirred for 1 h at 60 °C under nitrogen atmosphere. The reaction was cooled and quenched with water/sat. NH ₄ Cl (50 mL). This was extracted with 1:1 ether/EtOAc (2 x 50 mL). The combined extracts were washed with brine (50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]aniline (350 mg, 41% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 458 Synthesis of 124-b: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0679] To a stirred solution of 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]aniline (75 mg, 0.16 mmol, 1 equiv) in pyridine (2 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (48 mg, 0.2 mmol, 1.2 equiv) in portions at room temperature. The reaction was stirred for 3 h at room temperature then diluted with MeOH (2 mL) and concentrated. The residue was purified by reverse flash chromatography with the following conditions: column, C18 silica gel; mobile phase: 25-75% MeOH / water; detector, UV 254 nm; to give 5-chloro- N-[2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy] methyl]-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (50 mg, 46% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 663 Synthesis of Compound 124: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0680] To a stirred solution of 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (50 mg, 0.075 mmol, 1 equiv) in DCM (3 mL) was added TFA (1 mL). The resulting mixture was stirred for 2 h at room temperature then concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 17-53% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to afford 5-chloro-N-[2,4-difluoro-3- [1-(5-methyl-4H-1,2,4-triazol-3-yl)imidazo[1,5-a]pyrazin-6-y l]phenyl]-2-methoxypyridine-3- sulfonamide (25 mg, 62% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 533 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.79 (s, 1H), 10.45 (s, 1H), 9.55 (d, J = 1.8 Hz, 1H), 8.69- 8.56 (m, 2H), 8.51 (d, J = 2.6 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.46-7.37 (m, 1H), 7.24 (t, J = 9.1 Hz, 1H), 3.93 (s, 3H), 2.47 (s, 3H). Example 140: Synthesis of N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin- 6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide (Compound 125) Compound 125 Synthesis of Compound 125: N-[2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin- 6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide [0681] To a stirred solution of 2,4-difluoro-3-[1-(1,2-oxazol-5-yl)imidazo[1,5-a]pyridin-6- yl]aniline (100 mg, 0.3 mmol, 1 equiv) and pyridine (76 mg, 0.96 mmol, 3 equiv) in DCM (5 mL) was added 5-fluoro-2-methylpyridine-3-sulfonyl chloride (100 mg, 0.6 mmol, 1.5 equiv) at room temperature. The resulting mixture was stirred for 1 h, then concentrated under reduced pressure. The residue was purified by prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 5-40% MeCN / 0.05% aqueous ammonia; Detector 220 nm; to afford N-[2,4-difluoro-3-[1-(1,2-oxazol-5- yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyrid ine-3-sulfonamide (20 mg, 13% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 486 ¹ H NMR (300 MHz, Methanol-d ₄ ) δ 8.54 (d, J = 3.0 Hz, 2H), 8.50-8.43 (m, 2H), 8.11 (d, J = 9.5 Hz, 1H), 7.99 (dd, J = 8.2, 2.9 Hz, 1H), 7.50 (td, J = 9.0, 5.7 Hz, 1H), 7.17-7.02 (m, 2H), 6.75 (d, J = 2.0 Hz, 1H), 2.86 (d, J = 1.3 Hz, 3H).

Example 141: Synthesis of 5-cyano-N-[3-[1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide (Compound 126) Compound 126 Synthesis of 126-a: 4,5-dimethyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole [0682] Into a 40 mL vial were added 4,5-dimethyl-1H-imidazole hydrochloride (500 mg, 3.8 mmol, 1 equiv) and DMF (10 mL). The mixture was cooled to -30 °C and 60% NaH (180 mg, 7.5 mmol, 2 equiv) was added in portions. The resulting mixture was stirred for 30 min at -30 °C, then [2-(chloromethoxy)ethyl]trimethylsilane (628 mg, 3.8 mmol, 1 equiv) was added dropwise. The mixture was allowed to stir to 0 °C over 2 hrs, then quenched with water (100 mL). This was extracted with EtOAc (3 x 100 mL) and the combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 4,5-dimethyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole (800 mg, 94% yield) as a colorless oil. LCMS (ES, m/z): [M+H] ⁺ : 227. Synthesis of 126-b: 3-[1-(4,5-dimethyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imida zol-2- yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluoroaniline [0683] Into a 40 mL vial were added 4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole (367 mg, 1.6 mmol, 3 equiv) and THF (5 mL). n- BuLi (0.65 mL, 1.6 mmol, 3 equiv) was added dropwise at -78 °C. The resulting mixture was stirred for 1 h at -78 °C, then 1 M ZnCl ₂ solution (1.6 mL, 1.6 mmol, 3 equiv) was added. The mixture was stirred to room temperature over 1 hr. To the resultant mixture was added 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyridin-6-yl]aniline (200 mg, 0.54 mmol, 1 equiv) and Pd(PPh ₃ ) ₄ (62 mg, 0.054 mmol, 0.1 equiv). This was stirred for 30 min at 60 °C under N ₂ atmosphere. The resulting mixture was diluted with water (100 mL) and extracted with EtOAc (3 x 100 mL). The combined organics were washed with brine (3 x 50 mL), dried over anhydrous Na ₂ SO ₄ , and concentrated under reduced pressure. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 3-[1-(4,5- dimethyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)i midazo[1,5-a]pyridin-6-yl]-2,4- difluoroaniline (230 mg, 81% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 470. Synthesis of 126-c: 5-cyano-N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide [0684] Into an 8 mL vial were added 3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl]-2,4-difluoroaniline (180 mg, 0.38 mmol, 1 equiv), 5-cyano-2-methoxypyridine-3-sulfonyl chloride (180 mg, 0.77 mmol, 2 equiv) and pyridine (4 mL). The resulting mixture was stirred for 2 h at room temperature, then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/THF (1:1) to afford 5-cyano-N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 2-methoxypyridine-3-sulfonamide (190 mg, 55% yield) as a brown solid. LCMS (ES, m/z): [M+H] ⁺ : 666. Synthesis of Compound 126: 5-cyano-N-[3-[1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide [0685] Into an 8 mL vial were added 5-cyano-N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl]-2,4- difluorophenyl]-2-methoxypyridine-3-sulfonamide (180 mg, 0.27 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 40 °C, then concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column: XBridge Prep C18 OBD, 5 µm, 19*150 mm; Mobile Phase: 3-33% MeCN / 0.05% aqueous ammonia; Flow rate: 20 mL/min; to give 5-cyano-N-[3-[1-(4,5-dimethyl -1H-imidazol-2- yl)imidazo[1,5-a]pyridin-6-yl]-2,4-difluorophenyl]-2-methoxy pyridine-3-sulfonamide (31 mg, 22% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 536. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 11.58-11.52 (m, 2H), 8.90 (d, J = 2.2 Hz, 1H), 8.52-8.43 (m, 3H), 8.19 (d, J = 9.4 Hz, 1H), 7.35 (td, J = 8.9, 5.8 Hz, 1H), 7.24-7.12 (m, 1H), 6.87-6.77 (m, 1H), 4.01 (s, 3H), 2.14 (s, 6H). Example 142: Synthesis of N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide (Compound 127) Compound 127 Synthesis of 127-a: N-[2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy] methyl]- 1,2,4-triazol-3-yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluo ro-2-methoxypyridine-3- sulfonamide [0686] To a stirred solution of 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]aniline (65 mg, 0.14 mmol, 1 equiv) in pyridine (2 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride in portions. The mixture was stirred for 3 h then concentrated under reduced pressure. The residue was purified by prep-HPLC Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 µm, 120 g; mobile phase: 35- 95% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give N-[2,4-difluoro-3-[1-(5- methyl-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (60 mg, 65% yield) as a white solid. Synthesis of Compounds 127: N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyri dine-3-sulfonamide [0687] To a stirred solution of N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide (55 mg, 0.08 mmol, 1 equiv) in DCM (3 mL) was added TFA (1 mL) dropwise at 0 °C. The resulting mixture was stirred for 3 h at room temperature then concentrated under reduced pressure. The residue was purified by prep- HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 5-40% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give N- [2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl)imidazo[1 ,5-a]pyrazin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide (35 mg, 80% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 517 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 14.03 (d, J = 144.2 Hz, 1H), 10.43 (s, 1H), 9.55 (d, J = 1.8 Hz, 1H), 8.61 (d, J = 17.6 Hz, 1H), 8.46 (d, J = 3.0 Hz, 1H), 8.03 (dd, J = 7.3, 3.0 Hz, 1H), 7.41 (s, 1H), 7.23 (t, J = 9.2 Hz, 1H), 3.92 (s, 3H), 2.41 (d, J = 30.1 Hz, 3H).

Example 143: Synthesis of 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (Compound 128) Compound 128 Synthesis of 128-a: 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide [0688] To a stirred solution of 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]aniline (65 mg, 0.14 mmol, 1 equiv) in pyridine (2 mL) was added 5-cyano-2-methoxypyridine-3-sulfonyl chloride (66 mg, 0.28 mmol, 2 equiv) in portions and the mixture stirred for 6 h. The resulting mixture was concentrated and the residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 µm, 120 g; mobile phase: 25-95% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-cyano-N- [2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy]me thyl]-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (65 mg, 70% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 654 Synthesis of Compound 128: 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide [0689] To a stirred solution of 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (60 mg) in DCM (3 mL) was added TFA (1 mL) dropwise at 0 °C. The resulting mixture was stirred for 1 h then concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 3-29% MeCN / 0.05% aqueous ammonia; Detector, 220 nm; to give 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methoxypyridine-3-su lfonamide (25 mg) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 524 1H NMR (300 MHz, DMSO-d6) δ 14.04 (br s, 1H), 10.56 (br s, 1H), 9.55 (br s, 1H), 8.91 (br s, 1H), 8.90-8.40 (m, 3H), 7.42 (br s, 1H), 7.21 (br s, 1H), 4.01 (s, 3H), 2.39 (s, 3H). Example 144: Synthesis of N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluoro-2-methylpyrid ine-3-sulfonamide (Compound 129) Compound 129 Synthesis of 129-a: N-[2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy] methyl]- 1,2,4-triazol-3-yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluo ro-2-methylpyridine-3- sulfonamide [0690] To a stirred solution of 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]aniline (100 mg, 0.22 mmol, 1 equiv) in pyridine (2 mL) was added 5-fluoro-2-methylpyridine-3-sulfonyl chloride (137 mg, 0.66 mmol, 3 equiv) in portions at room temperature. The resulting mixture was stirred for 6 h then concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820- 40 µm, 120 g; mobile phase: 25-95% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give N-[2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy] methyl]-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluoro-2-methylpyrid ine-3-sulfonamide (100 mg, 73% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 631 Synthesis of Compound 129: N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluoro-2-methylpyrid ine-3-sulfonamide [0691] To a stirred solution of N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]phenyl]-5- fluoro-2-methylpyridine-3-sulfonamide (95 mg, 0.15 mmol, 1 equiv) in DCM (3 mL) in an ice bath was added TFA (1 mL) dropwise. The resulting mixture was stirred for 1 h at room temperature then concentrated under reduced pressure. The residue was purified by prep- HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 10-45% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give N- [2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3-yl)imidazo[1 ,5-a]pyrazin-6-yl]phenyl]-5- fluoro-2-methylpyridine-3-sulfonamide (44 mg, 58% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 501 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 14.02 (d, J = 143.3 Hz, 1H), 10.79 (s, 1H), 9.54 (d, J = 1.6 Hz, 1H), 8.78-8.68 (m, 1H), 8.64 (s, 1H), 8.56 (s, 1H), 7.95 (dd, J = 8.2, 2.8 Hz, 1H), 7.39 (q, J = 8.5 Hz, 1H), 7.28-7.16 (m, 1H), 2.78 (d, J = 1.2 Hz, 3H), 2.41 (d, J = 29.6 Hz, 3H).

Example 145: Synthesis of 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4- triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl] -2-methoxypyridine-3- sulfonamide & 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazo l-3-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyri dine-3-sulfonamide (Compounds 130-1 & 130-2) Synthesis of 130-a: 2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy]met hyl]-1,2,4- triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]aniline [0692] Into a 50 mL pressure tank reactor was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyridin-6-yl]aniline (500 mg, 1.1 mmol, 1 equiv) and MeOH (20 mL).20% Pd(OH) ₂ /C (500 mg) was added and the mixture stirred under 25 atm of hydrogen gas for 4 h at 70 °C. The reaction mixture was cooled and filtered. The filtrate was concentrated to give 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]aniline (600 mg, 92% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 461 Synthesis of 130-b: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide [0693] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]aniline (120 mg, 0.26 mmol, 1 equiv), pyridine (4 mL) and 5-chloro-2-methoxypyridine-3- sulfonyl chloride (95 mg, 0.39 mmol, 1.5 equiv). The resulting solution was stirred overnight then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 10- 90% MeCN / 0.1% aqueous formic acid; Detector, 220 nm; to give 5-chloro-N-[2,4-difluoro- 3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-tr iazol-3-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfo namide (100 mg, 58% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 666 Synthesis of Compounds 130-1 & 130-2: 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H- 1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]p henyl]-2-methoxypyridine-3- sulfonamide & 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazo l-3-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyri dine-3-sulfonamide [0694] Into a 40 mL vial was placed 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide (100 mg, 0.15 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 5 h then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 10-85% MeCN / 0.1% aqueous formic acid; Detector, 220 nm to give the racemic product. The enantiomers were separated using Chiral-Prep-HPLC with the following conditions: Column: CHIRAL ART Cellulose- SB, 3*25 cm, 5 µm; Mobile Phase: 25% EtOH / hexane containing 0.1% 2 M NH ₃ in MeOH; Flow rate: 55 mL/min; to give the single enantiomers 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(5- methyl-4H-1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyri din-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (RT 13.80 mins, 10 mg, 12% yield, stereochemistry randomly assigned) as a white solid and 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H- 1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]p henyl]-2-methoxypyridine-3- sulfonamide (RT 15.80 mins, 10 mg 12% yield, stereochemistry opposite to randomly assigned isomer) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 536 for both isomers 130-1: ¹ NMR (300 MHz, DMSO-d ₆ ) δ 13.56 (s, 1H), 10.34 (s, 1H), 8.50 (q, J = 2.5 Hz, 1H), 8.02 (q, J = 2.5 Hz, 1H), 7.65 (s, 1H), 7.25 (s, 1H), 7.10 (t, J = 9.6 Hz, 1H), 4.35-4.23 (m, 1H), 4.07-3.93 (m, 1H), 3.90 (s, 3H), 3.61-3.43 (m, 1H), 3.41-3.32 (m, 1H), 3.01-2.79 (m, 1H), 2.26 (s, 3H), 2.17-1.89 (m, 2H). 130-2: ¹ H NMR (300 MHz, DMSO-d6) δ 13.56 (s, 1H), 10.37 (s, 1H), 8.49 (d, J = 2.6 Hz, 1H), 8.01 (d, J = 2.5 Hz, 1H), 7.65 (s, 1H), 7.38-7.18 (m, 1H), 7.15-7.02 (m, 1H), 4.34-4.24 (m, 1H), 4.09-3.96 (m, 1H), 3.92 (s, 3H), 3.59-3.43 (m, 1H), 3.43-3.34 (m, 1H), 3.00-2.92 (m, 1H), 2.26 (s, 3H), 2.17-1.91 (m, 2H). Example 146: Synthesis of N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol-3-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-me thoxypyridine-3- sulfonamide & N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5 H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridin e-3-sulfonamide (Compounds 131-1 & 131-2) Synthesis of 131-a: N-[2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy] methyl]- 1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]p henyl]-5-fluoro-2- methoxypyridine-3-sulfonamide [0695] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]aniline (120 mg, 0.26 mmol, 1 equiv), pyridine (4 mL) and 5-fluoro-2-methoxypyridine-3- sulfonyl chloride (88 mg, 0.39 mmol, 1.5 equiv). The resulting solution was stirred overnight then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 20-90% MeCN / 0.1% aqueous formic acid to give N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (93 mg, 55% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 650 Synthesis of Compounds 131-1 & 131-2: N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5 H,6H,7H,8H-imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide & N-[2,4-difluoro-3- [(6R)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo [1,5-a]pyridin-6-yl]phenyl]- 5-fluoro-2-methoxypyridine-3-sulfonamide [0696] Into a 40 mL vial was placed N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (90 mg, 0.14 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 5 h then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 15-80% MeCN / 0.1% aqueous formic acid to give the racemic product. The enantiomers were separated using CHIRAL- Prep-HPLC with the following conditions: Column: CHIRAL ART Cellulose-SB, 3*25 cm, 5 µm; Mobile Phase: 25% EtOH / Hexane containing 0.1% 2 M NH ₃ in MeOH; Flow rate: 55 mL/min; to give N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5 H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridin e-3-sulfonamide (RT 13 mins, 25 mg, 35% yield, stereochemistry randomly assigned) as a white solid and N-[2,4-difluoro- 3-[(6R)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5H,6H,7H,8H-imida zo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (RT 16 mins, 10 mg 14% yield, stereochemistry opposite of randomly assigned isomer) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 520 for both isomers 131-1: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.56 (br s, 1H), 10.33 (br s, 1H), 8.47 (d, J = 3.0 Hz, 1H), 7.97 (dd, J = 7.3, 3.0 Hz, 1H), 7.66 (br s, 1H), 7.25 (td, J = 8.9, 5.7 Hz, 1H), 7.15- 7,05 (m, 1H), 4.30 (dd, J = 12.3, 5.2 Hz, 1H), 4.00 (t, J = 11.9 Hz, 1H), 3.92 (s, 3H), 3.60- 3.45 (m, 1H), 3.44-3.30 (m, 1H), 2.97-2.83 (m, 1H), 2.25 (br s, 3H), 2.30-1.92 (m, 2H). 131-2: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.55 (br s, 1H), 8.47 (d, J = 3.0 Hz, 1H), 7.98 (dd, J = 7.3, 3.0 Hz, 1H), 7.66 (br s, 1H), 7.24 (td, J = 8.9, 5.7 Hz, 1H), 7.15-7,05 (m, 1H), 4.30 (dd, J = 12.3, 5.2 Hz, 1H), 4.00 (t, J = 11.9 Hz, 1H), 3.91 (s, 3H), 3.62-3.47 (m, 1H), 3.40- 3.30 (m, 1H), 2.95-2.80 (m, 1H), 2.25 (br s, 3H), 2.30-1.92 (m, 2H). Example 147: Synthesis of 6-(3-((5-chloro-2-oxo-1,2-dihydropyridine)-3-sulfonamido)- 2,6-difluorophenyl)-N-methylimidazo[1,5-a]pyrazine-1-carboxa mide (Compound 132) Synthesis of Compound 132: 6-(3-((5-chloro-2-oxo-1,2-dihydropyridine)-3-sulfonamido)- 2,6-difluorophenyl)-N-methylimidazo[1,5-a]pyrazine-1-carboxa mide [0697] HBr (50% aqueous, 48 µL, 0.29 mmol, 3 equiv) was added to a suspension of 6-(3- ((5-chloro-2-methoxypyridine)-3-sulfonamido)-2,6-difluorophe nyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (50 mg, 0.098 mmol, 1 equiv) in AcOH (1.0 mL) and the mixture was heated to 80 °C for 2.5 hours and then concentrated under reduced pressure. The crude residue was purified by Prep-HPLC with the following conditions: Column, RediSep Prep C18, 100 Å, 5 µm, 150 × 20 mm; mobile phase: 5-40% MeCN / 0.1% aqueous ammonium hydroxide; Detector, 254 nm; to afford 6-(3-((5-chloro-2-oxo-1,2-dihydropyridine)-3- sulfonamido)-2,6-difluorophenyl)-N-methylimidazo[1,5-a]pyraz ine-1-carboxamide (15 mg, 31% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 495. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 12.83 (br s, 1H), 9.52 (dd, J = 1.7, 0.6 Hz, 1H), 8.71 – 8.68 (m, 1H), 8.66 (d, J = 0.6 Hz, 1H), 8.43 (q, J = 4.7 Hz, 1H), 8.05 (d, J = 2.9 Hz, 1H), 7.41 (td, J = 8.9, 5.8 Hz, 1H), 7.23 (td, J = 9.1, 1.6 Hz, 1H), 2.84 (d, J = 4.8 Hz, 3H). Example 148: Synthesis of 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methylpyridine-3-sul fonamide (Compound 133) Compound 133 Synthesis of 133-a: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide [0698] To a stirred solution of 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]aniline (100 mg, 0.22 mmol, 1 equiv) in pyridine (2 mL) was added 5-chloro-2-methylpyridine-3-sulfonyl chloride (74 mg, 0.33 mmol, 1.5 equiv) in portions at room temperature. The resulting mixture was stirred for 6 h then concentrated under reduced pressure. The residue was purified by prep-HPLC Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 µm, 120 g; mobile phase: 25-95% MeCN / 0.1% aqueous formic acid; to give 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (70 mg, 49% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 647 Synthesis of Compound 133: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H-1,2,4-triazol-3- yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-methylpyridine-3-sul fonamide [0699] To a stirred solution of 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)imidazo[1, 5-a]pyrazin-6-yl]phenyl]-2- methylpyridine-3-sulfonamide (65 mg) in DCM (3 mL) in an ice bath was added TFA (1 mL) dropwise. The resulting mixture was stirred for 1 h at room temperature then concentrated under reduced pressure. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 10-50% MeCN / 0.1% aqueous formic acid; to give 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4H- 1,2,4-triazol-3-yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-2-meth ylpyridine-3-sulfonamide (32 mg) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 517 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 14.03 (d, J = 143.1 Hz, 1H), 10.79 (s, 1H), 9.54 (d, J = 1.6 Hz, 1H), 8.76 (d, J = 2.4 Hz, 1H), 8.65 (s, 1H), 8.61-8.54 (m, 1H), 8.09 (d, J = 2.4 Hz, 1H), 7.40 (td, J = 8.8, 5.7 Hz, 1H), 7.31-7.19 (m, 1H), 2.78 (s, 3H), 2.42 (d, J = 27.7 Hz, 3H). Example 149: Synthesis of N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol-3-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-me thylpyridine-3- sulfonamide & N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5 H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine -3-sulfonamide (Compounds 134-1 & 134-2) Synthesis of 134-a: N-[2,4-difluoro-3-[1-(5-methyl-4-[[2-(trimethylsilyl)ethoxy] methyl]- 1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]p henyl]-5-fluoro-2- methylpyridine-3-sulfonamide [0700] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]aniline (120 mg, 0.26 mmol, 1 equiv), pyridine (4 mL) and 5-fluoro-2-methylpyridine-3- sulfonyl chloride (82 mg, 0.39 mmol, 1.5 equiv). The resulting solution was stirred overnight then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 30- 85% MeCN / 0.1% aqueous formic acid; to give N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonamide (88 mg, 53% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 634 Synthesis of Compounds 134-1 & 134-2: N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4- triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl] -5-fluoro-2-methylpyridine-3- sulfonamide & N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5 H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine -3-sulfonamide [0701] Into a 40 mL vial was placed N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (90 mg, 0.14 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 5 h then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 15-75% MeCN / 0.1% aqueous formic acid to give the racemic product. The enantiomers were separated using Chiral-Prep-HPLC; Column: CHIRALPAK IE, 3*25 cm, 5 µm; Mobile Phase: 18% MeOH / MTBE containing 0.2% diethylamine; Flow rate: 35 mL/min; to give N-[2,4-difluoro-3- [(6S)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo [1,5-a]pyridin-6-yl]phenyl]- 5-fluoro-2-methylpyridine-3-sulfonamide (RT 17 mins, 25 mg, 35% yield, stereochemistry randomly assigned) as a white solid, and N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4- triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl] -5-fluoro-2-methylpyridine-3- sulfonamide (RT 19 mins, 10 mg 14% yield, stereochemistry assigned as opposite to other enantiomer) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 504 for both isomers 134-1: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.56 (br s, 1H), 10.66 (br s, 1H), 8.70 (d, J = 2.8 Hz, 1H), 7.87 (dd, J = 8.3, 2.9 Hz, 1H), 7.65 (s, 1H), 7.22 (td, J = 8.9, 5.7 Hz, 1H), 7.07 (t, J = 9.4 Hz, 1H), 4.27 (dd, J = 12.3, 5.2 Hz, 1H), 3.97 (t, J = 12.0 Hz, 1H), 3.61-3.43 (m, 1H), 3.43-3.33 (m, 1H), 2.93-2.87 (m, 1H), 2.74 (d, J = 1.2 Hz, 3H), 2.26 (s, 3H), 2.17-1.90 (m, 2H). 134-2: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.56 (br s, 1H), 10.69 (br s, 1H), 8.74 (d, J = 2.8 Hz, 1H), 7.87 (dd, J = 8.2, 2.8 Hz, 1H), 7.64 (s, 1H), 7.25 (td, J = 8.8, 5.7 Hz, 1H), 7.17-7.05 (m, 1H), 4.27 (dd, J = 12.2, 5.1 Hz, 1H), 3.96 (t, J = 11.9 Hz, 1H), 3.53-3.43 (m, 1H), 3.42- 3.33 (m, 1H), 2.89 (ddd, J = 17.6, 11.6, 6.4 Hz, 1H), 2.74 (d, J = 1.2 Hz, 3H), 2.27 (s, 3H), 2.17-1.87 (m, 2H). Example 150: Synthesis of 5-cyano-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol - 3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-metho xypyridine-3- sulfonamide & 5-cyano-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazol -3-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyri dine-3-sulfonamide (Compounds 135-1 & 135-2) Synthesis of 135-a: 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide [0702] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]aniline (120 mg, 0.26 mmol, 1 equiv), pyridine (4 mL) and 5-cyano-2-methoxypyridine-3- sulfonyl chloride (91 mg, 0.4 mmol, 1.5 equiv). The resulting solution was stirred for 16 h then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20- 90% MeCN / 0.1% aqueous formic acid; to give 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4- [[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H ,7H,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide (90 mg, 53% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 657 Synthesis of Compounds 135-1 & 135-2: 5-cyano-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H- 1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]p henyl]-2-methoxypyridine-3- sulfonamide & 5-cyano-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazol -3-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyri dine-3-sulfonamide [0703] Into an 8 mL vial was placed 5-cyano-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methoxypyridine-3-sulfonamide (90 mg, 0.14 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 5 h then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20-90% MeCN / 0.1% aqueous formic acid; to give the racemic product. The enantiomers were separated by Chiral- Prep-HPLC with the following conditions: Column: CHIRALPAK IE, 2*25 cm, 5 µm; Mobile Phase: 18% MeOH / MTBE (containing 0.1% DEA; Flow rate: 35 mL/min; to give 5- cyano-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol-3 -yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfo namide(RT 19 mins, 10 mg, 14% yield, stereochemistry randomly assigned) and 5-cyano-N-[2,4-difluoro-3-[(6R)-1-(5- methyl-4H-1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyri din-6-yl]phenyl]-2- methoxypyridine-3-sulfonamide (RT 21 mins, 15 mg, 21% yield, stereochemistry assigned as opposite to other enantiomer) as white solids. LCMS (ES, m/z): [M+H] ⁺ : 527 for both isomers 135-1: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.56 (br s, 1H), 8.83 (d, J = 2.3 Hz, 1H), 8.36 (d, J = 2.3 Hz, 1H), 7.66 (s, 1H), 7.23-7.12 (m, 1H), 6.96 (t, J = 9.5 Hz, 1H), 4.35-4.25 (m, 1H), 4.05 (d, J = 11.4 Hz, 1H), 3.97 (s, 3H), 3.60-3.37 (m, 2H), 3.00-2.83 (m, 1H), 2.26 (s, 3H), 2.18-1.96 (m, 2H). 135-2: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.57 (br s, 1H), 10.44 (br s, 1H), 8.91 (s, 1H), 8.42 (d, J = 2.2 Hz, 1H), 7.66 (s, 1H), 7.28-7.21 (m, 1H), 7.07 (t, J = 9.5 Hz, 1H), 4.29 (s, 1H), 4.09-3.91 (m, 4H), 3.62-3.44 (m, 1H), 3.43-3.35 (m, 1H), 2.94-2.88 (m, 1H), 2.25 (s, 3H), 2.18-1.98 (m, 2H). Example 151: Synthesis of 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4- triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl] -2-methylpyridine-3- sulfonamide & 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazo l-3-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyrid ine-3-sulfonamide (Compounds 136-1 & 136-2) Compound 136-1 Compound 136-2 Synthesis of 136-a: 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide [0704] Into a 40 mL vial was placed 2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]aniline (120 mg, 0.26 mmol, 1 equiv), pyridine (4 mL) and 5-chloro-2-methylpyridine-3- sulfonyl chloride (77 mg, 0.34 mmol, 1.3 equiv). The resulting solution was stirred overnight then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20- 90% MeCN / 0.1% aqueous formic acid; to give 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4- [[2-(trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H ,7H,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide (88 mg, 52% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 650 Synthesis of Compounds 136-1 & 136-2: 5-chloro-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H- 1,2,4-triazol-3-yl)-5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]p henyl]-2-methylpyridine-3- sulfonamide & 5-chloro-N-[2,4-difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazo l-3-yl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyrid ine-3-sulfonamide [0705] Into a 40 mL vial was placed 5-chloro-N-[2,4-difluoro-3-[1-(5-methyl-4-[[2- (trimethylsilyl)ethoxy]methyl]-1,2,4-triazol-3-yl)-5H,6H,7H, 8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide (100 mg, 0.15 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 5 h then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20-90% MeCN / 0.1% aqueous formic acid to give the racemic product. The enantiomers were separated via Chiral- Prep-HPLC with the following conditions: Column: CHIRALPAK IE, 3*25 cm, 5 µm; Mobile Phase 15% MeOH / MTBE containing 0.1% DEA; Flow rate: 35 mL/min; to give 5- chloro-N-[2,4-difluoro-3-[(6S)-1-(5-methyl-4H-1,2,4-triazol- 3-yl)-5H,6H,7H,8H- imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfon amide (RT 23 mins, 10 mg, 13% yield, stereochemistry randomly assigned) as a white solid and 5-chloro-N-[2,4- difluoro-3-[(6R)-1-(5-methyl-4H-1,2,4-triazol-3-yl)-5H,6H,7H ,8H-imidazo[1,5-a]pyridin-6- yl]phenyl]-2-methylpyridine-3-sulfonamide (RTRT 27 mins, 10 mg, 13% yield, stereochemistry opposite to randomly assigned isomer) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 520 for both isomers 136-1: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.57 (br s, 1H), 10.69 (br s, 1H), 8.77 (d, J = 2.4 Hz, 1H), 7.98 (d, J = 2.4 Hz, 1H), 7.64 (s, 1H), 7.26 (td, J = 8.8, 5.7 Hz, 1H), 7.12 (t, J = 9.3 Hz, 1H), 4.27 (dd, J = 12.4, 5.1 Hz, 1H), 3.96 (t, J = 11.9 Hz, 1H), 3.78 (s, 3H), 3.60-3.43 (m, 1H), 3.43-3.33 (m, 1H), 3.02-2.81 (m, 1H), 2.27 (br s, 3H), 2.19-1.87 (m, 2H). 136-2: ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.56 (br s, 1H), 10.68 (br s, 1H), 8.77 (d, J = 2.4 Hz, 1H), 7.98 (d, J = 2.4 Hz, 1H), 7.64 (s, 1H), 7.26 (td, J = 8.8, 5.7 Hz, 1H), 7.19-7.04 (m, 1H), 4.27 (dd, J = 12.3, 5.2 Hz, 1H), 3.96 (t, J = 11.9 Hz, 1H), 3.59-3.41 (m, 1H), 3.43-3.30 (m, 1H), 2.98-2.78 (m, 1H), 2.75 (s, 3H), 2.28 (s, 3H), 2.20-1.87 (m, 2H). Example 152: Synthesis of 6-[6-chloro-3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2- fluorophenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxamide (Compound 137) Compound 137 Synthesis of 137-a: 6-(3-amino-6-chloro-2-fluorophenyl)-N-methylimidazo[1,5-a]py ridine-1- carboxamide [0706] Into an 8 mL vial was placed methyl 6-(3-amino-6-chloro-2- fluorophenyl)imidazo[1,5-a]pyridine-1-carboxylate (130 mg, 0.4 mmol, 1 equiv) and 33% methylamine in ethanol solution (3 mL). The resulting solution was stirred for 24 h at 60 °C then was concentrated under reduced pressure to give crude 6-(3-amino-6-chloro-2- fluorophenyl)-N-methylimidazo[1,5-a]pyridine-1-carboxamide (100 mg) as a brown solid which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 319 Synthesis of Compounds 137: 6-[6-chloro-3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2- fluorophenyl]-N-methylimidazo[1,5-a]pyridine-1-carboxamide [0707] Into an 8 mL vial was placed 6-(3-amino-6-chloro-2-fluorophenyl)-N- methylimidazo[1,5-a]pyridine-1-carboxamide (100 mg, 0.3 mmol, 1 equiv), pyridine (3 mL) and 5-chloro-2-methoxypyridine-3-sulfonyl chloride (92 mg, 0.4 mmol, 1.2 equiv). The resulting solution was stirred for 2 h then concentrated under vacuum. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 40-80% MeCN / 0.1% aqueous formic acid to afford 6-[6- chloro-3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2-fluoro phenyl]-N- methylimidazo[1,5-a]pyridine-1-carboxamide (45 mg, 27% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 524 1H NMR (300 MHz, DMSO-d ₆ ) δ 10.62 (s, 1H), 8.57-8.45 (m, 3H), 8.20-8.07 (m, 3H), 7.47 (d, J = 9.0 Hz, 1H), 7.47-7.35 (m, 1H), 6.96 (d, J = 9.3 Hz, 1H), 3.90 (s, 3H), 2.81 (d, J = 4.7 Hz, 3H). Example 153: Synthesis of 2-[6-chloro-3-(5-chloro-2-methylpyridine-3-sulfonamido)-2- fluorophenyl]-N-methylimidazo[1,5-b]pyridazine-5-carboxamide (Compounds 138) Synthesis of 138-a: methyl 6-(3-amino-6-chloro-2-fluorophenyl)imidazo[1,5-a]pyrazine-1- carboxylate [0708] Into an 8 mL vial were added ethyl 2-bromoimidazo[1,5-b]pyridazine-5-carboxylate (200 mg, 0.74 mmol, 1 equiv), 4-chloro-2-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)aniline (301 mg, 1.1 mmol, 1.5 equiv), Pd(dtbpf)Cl ₂ (48 mg, 0.07 mmol, 0.1 equiv), KF (129 mg, 2.2 mmol, 3 equiv), dioxane (4 mL) and H ₂ O (0.8 mL). The resulting mixture was stirred for 1 h at 80 °C under nitrogen atmosphere, then concentrated. The residue was purified by silica gel column chromatography, eluting with (PE:EA=1:5) to afford ethyl 2-(3- amino-6-chloro-2-fluorophenyl)imidazo[1,5-b]pyridazine-5-car boxylate (17 mg, 69% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 335 Synthesis of 138-b: 6-(3-amino-6-chloro-2-fluorophenyl)-N-methylimidazo[1,5-a]py razine-1- carboxamide [0709] Into a 40 mL vial were added ethyl 2-(3-amino-6-chloro-2-fluorophenyl)imidazo[1,5- b]pyridazine-5-carboxylate (160 mg, 0.48 mmol, 1 equiv), MeOH (3 mL) and 30% methylamine in water (3 mL). The resulting mixture was stirred for 2 h at 60 °C, then concentrated. The residue was purified by silica gel column chromatography, eluting with CH ₂ Cl ₂ / MeOH (10:1) to afford 2-(3-amino-6-chloro-2-fluorophenyl)-N-methylimidazo[1,5- b]pyridazine-5-carboxamide (125 mg, 82% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 320 Synthesis of Compound 138: 2-[6-chloro-3-(5-chloro-2-methylpyridine-3-sulfonamido)-2- fluorophenyl]-N-methylimidazo[1,5-b]pyridazine-5-carboxamide [0710] Into an 8 mL vial were added 2-(3-amino-6-chloro-2-fluorophenyl)-N- methylimidazo[1,5-b]pyridazine-5-carboxamide (115 mg, 0.36 mmol, 1 equiv), 5-chloro-2- methylpyridine-3-sulfonyl chloride (161 mg, 0.7 mmol, 2 equiv) and pyridine (5 mL). The resulting mixture was stirred for 2 h then concentrated. The crude product was purified by Prep-HPLC with the following conditions: Column: XBridge Prep C18 OBD, 5 µm, 19*150 mm; Mobile Phase: 10-35% MeCN / 0.05% aqueous ammonia; to afford 2-[6-chloro-3-(5- chloro-2-methylpyridine-3-sulfonamido)-2-fluorophenyl]-N-met hylimidazo[1,5- b]pyridazine-5-carboxamide (32 mg, 18% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 509. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 11.04 (s, 1H), 8.86 (s, 1H), 8.72 (d, J = 2.4 Hz, 1H), 8.58 (d, J = 9.4 Hz, 1H), 8.32 (q, J = 4.7 Hz, 1H), 8.13 (d, J = 2.4 Hz, 1H), 7.51-7.36 (m, 2H), 7.08 (d, J = 9.4 Hz, 1H), 2.82 (d, J = 4.7 Hz, 3H), 2.77 (s, 3H).

Example 154: Synthesis of 2-[2-chloro-3-(5-chloro-2-methylpyridine-3-sulfonamido)-6- fluorophenyl]-N-methylimidazo[1,5-b]pyridazine-5-carboxamide (Compound 139) Synthesis of 139-a: ethyl 2-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5-b]pyridazine- 5- carboxylate [0711] Into a 40 mL vial purged and maintained with an inert atmosphere of nitrogen, was placed ethyl 2-bromoimidazo[1,5-b]pyridazine-5-carboxylate (180 mg, 0.67 mmol, 1 equiv), dioxane (10 mL), H ₂ O (2 mL), 2-chloro-4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)aniline (217 mg, 0.8 mmol, 1.2 equiv), K ₃ PO ₄ (283 mg, 1.3 mmol, 2 equiv) and Pd(dppf)Cl ₂ (49 mg, 0.067 mmol, 0.1 equiv). The resulting solution was stirred for 2 h at 90 °C then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 10-80% MeCN / 0.1% aqueous formic acid; to give ethyl 2-(3-amino-2-chloro-6- fluorophenyl)imidazo[1,5-b]pyridazine-5-carboxylate (120 mg, 54% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 335 Synthesis of 139-b: 2-(3-amino-2-chloro-6-fluorophenyl)-N-methylimidazo[1,5-b]py ridazine- 5-carboxamide [0712] Into a 40 mL vial was placed ethyl 2-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5- b]pyridazine-5-carboxylate (180 mg, 0.54 mmol, 1 equiv), MeOH (10 mL) and 30% aqueous methylamine (3 mL). The resulting solution was stirred overnight at 45 °C then concentrated to give 2-(3-amino-2-chloro-6-fluorophenyl)-N-methylimidazo[1,5-b]py ridazine-5- carboxamide (120 mg, 70% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 320 Synthesis of Compound 139: 2-[2-chloro-3-(5-chloro-2-methylpyridine-3-sulfonamido)-6- fluorophenyl]-N-methylimidazo[1,5-b]pyridazine-5-carboxamide [0713] Into a 40 mL vial was placed 2-(3-amino-2-chloro-6-fluorophenyl)-N- methylimidazo[1,5-b]pyridazine-5-carboxamide (120 mg, 0.38 mmol, 1 equiv), pyridine (5 mL) and 5-chloro-2-methylpyridine-3-sulfonyl chloride (127 mg, 0.56 mmol, 1.5 equiv). The resulting solution was stirred for 2 days then concentrated. The crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 10-65% MeCN / 0.1% aqueous ammonia; to give 2-[2-chloro-3-(5- chloro-2-methylpyridine-3-sulfonamido)-6-fluorophenyl]-N-met hylimidazo[1,5- b]pyridazine-5-carboxamide (40 mg, 21% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 509 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.84 (br s, 1H), 8.86 (s, 1H), 8.75 (d, J = 2.4 Hz, 1H), 8.58 (d, J = 9.4 Hz, 1H), 8.32 (q, J = 4.7 Hz, 1H), 8.04 (d, J = 2.4 Hz, 1H), 7.51 (dd, J = 9.1, 5.7 Hz, 1H), 7.44 (t, J = 8.8 Hz, 1H), 7.06 (d, J = 9.4 Hz, 1H), 2.86 (d, 3H), 2.74 (s, 3H). Example 155: Synthesis of 6-(2-fluoro-5-((5-fluoro-2-methoxypyridine)-3- sulfonamido)phenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a ]pyridine-1- carboxamide (Compound 140) Synthesis of 140-a: methyl 6-(5-amino-2-fluorophenyl)-5,6,7,8-tetrahydroimidazo[1,5- a]pyridine-1-carboxylate [0714] To a solution of methyl 6-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5-a]pyridine- 1-carboxylate (100 mg, 0.3 mmol, 1 equiv) in 10 mL MeOH was added Pd/C (10%, 66 mg) in a pressure tank. The mixture was hydrogenated at room temperature under 20 atm of hydrogen pressure for 2 h at 80 °C, then filtered through a Celite pad. The filtrate was concentrated and the residue was purified by silica gel column chromatography, eluting with PE:EA(1:1) to afford methyl 6-(5-amino-2-fluorophenyl)-5,6,7,8-imidazo[1,5-a]pyridine-1- carboxylate (60 mg, 66% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 290 Synthesis of 140-b: 6-(5-amino-2-fluorophenyl)-N-methyl-5,6,7,8-imidazo[1,5-a]py ridine-1- carboxamide [0715] To a solution of methyl 6-(5-amino-2-fluorophenyl)-5,6,7,8-imidazo[1,5-a]pyridine- 1-carboxylate (60 mg) and CH ₃ NH ₂ solution in MeOH (5 mL, 2 M) was stirred at 80 °C for 20 h. The mixture was cooled and concentrated to give crude 6-(5-amino-2-fluorophenyl)-N- methyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (60 mg). LCMS (ES, m/z): [M+H] ⁺ : 289 Synthesis of Compound 140: 6-(2-fluoro-5-((5-fluoro-2-methoxypyridine)-3- sulfonamido)phenyl)-N-methyl-5,6,7,8-tetrahydroimidazo[1,5-a ]pyridine-1-carboxamide [0716] To a stirred solution of 6-(5-amino-2-fluorophenyl)-N-methyl-5,6,7,8-imidazo[1,5- a]pyridine-1-carboxamide (60 mg, 0.2 mmol, 1 equiv) and pyridine (49 mg, 0.6 mmol, 3 equiv) in DCM (5 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (70 mg, 0.3 mmol, 1.5 equiv). The reaction was stirred for 1 h then concentrated. The residue was purified by prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 15-55% MeCN / 0.1% aqueous formic acid; to afford 6-(2- fluoro-5-((5-fluoro-2-methoxypyridine)-3-sulfonamido)phenyl) -N-methyl-5,6,7,8- tetrahydroimidazo[1,5-a]pyridine-1-carboxamide (60 mg, 60% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 478 ¹ H NMR (300 MHz, Chloroform-d) δ 8.19 (d, J = 3.0 Hz, 1H), 7.83 (dd, J = 6.8, 3.0 Hz, 1H), 7.34 (s, 1H), 7.26 (s, 1H), 7.10-7.01 (m, 2H), 6.98 (d, J = 7.8 Hz, 2H), 4.28 (dd, J = 12.2, 5.0 Hz, 1H), 4.16 (s, 3H), 3.86 (q, J = 11.8 Hz, 1H), 3.64-3.51 (m, 1H), 3.46 (d, J = 11.4 Hz, 1H), 3.07 (td, J = 11.4, 5.6 Hz, 1H), 2.98 (d, J = 4.8 Hz, 3H), 2.20-1.97 (m, 2H). Example 156: Synthesis of 6-(6-chloro-3-((5-chloro-2-methoxypyridine)-3-sulfonamido)- 2-fluorophenyl)-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 141) Synthesis of 141-a: 3-bromo-4-chloro-2-fluoroaniline [0717] To a stirred solution of 3-bromo-2-fluoroaniline (5 g, 26 mmol, 1 equiv) in DMF (25 mL) was added NCS (3.69 g, 28 mmol, 1.05 equiv) in portions at 0 °C. The reaction was stirred overnight then quenched by the addition of water/ice (25 mL). The resulting mixture was extracted with EtOAc (3 x 100 mL) and the combined organics washed with water and brine, then dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-30%) to afford 3-bromo-4-chloro-2- fluoroaniline (3 g, 51% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 224, 226 Synthesis of 141-b: 4-chloro-2-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)aniline [0718] A solution of 3-bromo-4-chloro-2-fluoroaniline (200 mg, 0.89 mmol, 1 equiv), bis(pinacolato)diboron (339 mg, 1.3 mmol, 1.5 equiv), tricyclohexylphosphine (50 mg, 0.18 mmol, 0.2 equiv), Pd ₂ (dba) ₃ (81 mg, 0.09 mmol, 0.1 equiv) and KOAc (175 mg, 1.8 mmol, 2 equiv) in dioxane (2 mL) was stirred for 16 h at 100 °C under nitrogen atmosphere. The mixture was cooled and diluted with water (10 mL), then extracted with EtOAc (3 x 50 mL). The combined organics were washed with water and brine, dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with EtOAc/PE (0-50%) to afford 4-chloro-2-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2- yl)aniline (150 mg, 62% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 272. Synthesis of 141-c: methyl 6-(3-amino-6-chloro-2-fluorophenyl)imidazo[1,5-a]pyrazine-1- carboxylate [0719] Into an 8 mL vial were added ethyl 6-bromoimidazo[1,5-a]pyrazine-1-carboxylate (200 mg, 0.74 mmol, 1 equiv), 4-chloro-2-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl) aniline (295 mg, 1.1 mmol, 1.5 equiv), Pd(dtbpf)Cl ₂ (53 mg, 0.08 mmol, 0.1 equiv), KF (126 mg, 2.2 mmol, 3 equiv), dioxane (4 mL) and H ₂ O (0.8 mL). The resulting mixture was stirred for 1 h at 80 °C under nitrogen atmosphere, then concentrated. The residue was purified by silica gel column chromatography, eluting with (PE:EA=1:5) to afford methyl 6- (3-amino-6-chloro-2-fluorophenyl)imidazo[1,5-a]pyrazine-1-ca rboxylate (160 mg, 67% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 335. Synthesis of 141-d: 6-(3-amino-6-chloro-2-fluorophenyl)-N-methylimidazo[1,5-a]py razine-1- carboxamide [0720] Into a 40 mL vial were added methyl 6-(3-amino-6-chloro-2- fluorophenyl)imidazo[1,5-a]pyrazine-1-carboxylate (160 mg, 0.5 mmol, 1 equiv), MeOH (3 mL) and 30% aqueous methylamine (3 mL). The resulting mixture was stirred for 2 h at 60 °C, then concentrated. The residue was purified by silica gel column chromatography, eluting with CH ₂ Cl ₂ / MeOH (10:1) to afford 6-(3-amino-6-chloro-2-fluorophenyl)-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (110 mg, 69% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 320. Synthesis of Compound 141: 6-(6-chloro-3-((5-chloro-2-methoxypyridine)-3-sulfonamido)- 2-fluorophenyl)-N- methylimidazo[1,5-a]pyrazine-1-carboxamide [0721] Into an 8 mL vial were added 6-(3-amino-6-chloro-2-fluorophenyl)-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (100 mg, 0.31 mmol, 1 equiv), 5-chloro-2- methoxypyridine-3-sulfonyl chloride (150 mg, 0.62 mmol, 2 equiv) and pyridine (5 mL). The resulting mixture was stirred for 2 h then concentrated. The crude product was purified by Prep-HPLC with the following conditions: Column: XBridge Prep C18 OBD, 5 µm, 19*150 mm; Mobile Phase: 10-35% MeCN / 0.05% aqueous ammonia; Flow rate: 20 mL/min; to give 6-[6-chloro-3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2-f luorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (61 mg, 37% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 525. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.62 (s, 1H), 9.52 (d, J = 1.7 Hz, 1H), 8.69-8.60 (m, 2H), 8.50 (d, J = 2.6 Hz, 1H), 8.43 (d, J = 5.0 Hz, 1H), 8.13 (d, J = 2.6 Hz, 1H), 7.44 (d, J = 3.9 Hz, 2H), 3.90 (s, 3H), 2.85 (d, J = 4.7 Hz, 3H). Example 157: Synthesis of N-[4-chloro-2-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide (Compound 142) Synthesis of 142-a: 4-chloro-2-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)aniline [0722] A solution of 3-bromo-4-chloro-2-fluoroaniline (200 mg, 0.89 mmol, 1 equiv), bis(pinacolato)diboron (340 mg, 1.34 mmol, 1.5 equiv), tricyclohexylphosphine (50 mg, 0.18 mmol, 0.2 equiv), Pd ₂ (dba) ₃ (82 mg, 0.09 mmol, 0.1 equiv) and KOAc (175 mg, 1.78 mmol, 2 equiv) in dioxane (2 mL) was stirred for 5 h at 100 °C under nitrogen atmosphere. The mixture was cooled and diluted with water (10 mL), then was extracted with EtOAc (3 x 50 mL). The combined organics were washed with H ₂ O (50 mL) and brine (50 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (2/1) to afford 4-chloro-2-fluoro-3-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (150 mg, 62% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 272 Synthesis of 142-b: 6-(3-amino-6-chloro-2-fluorophenyl)imidazo[1,5-a]pyrazine-1- carbonitrile [0723] To a stirred solution of 6-bromoimidazo[1,5-a]pyrazine-1-carbonitrile (510 mg, 2.3 mmol, 1 equiv) and 4-chloro-2-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)aniline (930 mg, 3.4 mmol, 1.5 equiv) in dioxane (5 mL) and H ₂ O (0.5 mL) were added KF (399 mg, 6.9 mmol, 3 equiv) and Pd(dtbpf)Cl ₂ (149 mg, 0.23 mmol, 0.1 equiv) in portions at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 1 h at 80 °C then quenched with H ₂ O (20 mL) and extracted with EA (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 30-80% MeCN / 0.1% aqueous formic acid; to afford 6-(3-amino-6-chloro-2-fluorophenyl)imidazo[1,5-a]pyrazine-1- carbonitrile (607 mg, 92% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 288 Synthesis of 142-c: 4-chloro-2-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyraz in-6- yl]aniline [0724] To a stirred solution of 6-(3-amino-6-chloro-2-fluorophenyl)imidazo[1,5-a]pyrazine- 1-carbonitrile (300 mg, 1 mmol, 1 equiv) in MeOH (5 mL) in an ice bath was added MeONa (225 mg, 4.2 mmol, 4 equiv) in portions. The resulting mixture was stirred for 2 h at 50 °C, then cooled to room temperature.2,2-Dimethoxyethanamine (132 mg, 1.3 mmol, 1.2 equiv) was added dropwise over 2 min then this was stirred for 2 h at 50 °C. The mixture was allowed to cool and 6 M aqueous HCl (8.8 mL) was added dropwise over 2 min. The resulting mixture was stirred for 1 h at 100 °C. H ₂ O (10 mL) was added and the mixture extracted with EA (3 x 5 mL). The combined organics were washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20-70% MeCN / 0.1% aqueous formic acid; to afford 4-chloro-2-fluoro-3-[1- (1H-imidazol-2-yl)imidazo[1,5-a]pyrazin-6-yl]aniline (66 mg, 19% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 329 Synthesis of 142-d: 4-chloro-2-fluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl] imidazol-2- yl)imidazo[1,5-a]pyrazin-6-yl]aniline [0725] To a stirred solution of 4-chloro-2-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]aniline (75 mg, 0.23 mmol, 1 equiv) in THF (4 mL) was added 60% NaH in oil (16 mg, 0.68 mmol, 3 equiv) in portions at 0 °C. The resulting mixture was stirred for 0.5 h at room temperature then SEMCl (57 mg, 0.34 mmol, 1.5 equiv) was added dropwise at 0 °C. The resulting mixture was stirred for 1 h at room temperature, before H ₂ O (5 mL) was added. This was extracted with EA (3 x 3 mL), and the combined organics were washed with brine (5 mL), dried over anhydrous Na ₂ SO ₄ then concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20-70% MeCN / 0.1% aqueous formic acid; to afford 4- chloro-2-fluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]aniline (54 mg, 52% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 459 Synthesis of 142-e: N-[4-chloro-2-fluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]meth yl]imidazol- 2-yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypy ridine-3-sulfonamide [0726] To a stirred solution of 4-chloro-2-fluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]aniline (50 mg, 0.11 mmol, 1 equiv) in pyridine (2 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (49 mg, 0.22 mmol, 2 equiv) in DCM (0.5 mL) dropwise. The resulting mixture was stirred for 1 h then concentrated to give crude N-[4-chloro-2-fluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide as a yellow oil, which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 648 Synthesis of Compound 142: N-[4-chloro-2-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide [0727] Into a 40 mL vial was placed N-[4-chloro-2-fluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (50 mg, 0.08 mmol, 1 equiv), DCM (1.5 mL) and TFA (0.5 mL). The resulting solution was stirred for 0.5 h then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 20-60% MeCN / 0.1% aqueous formic acid; to afford N-[4- chloro-2-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyrazin -6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (20 mg, 50% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 518 Example 158: Synthesis of 5-chloro-N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl)-2,4- difluorophenyl)-2-methoxypyridine-3-sulfonamide (Compound 143) Compound 143 Synthesis of 143-a: 5-chloro-N-(3-(1-(4,5-dimethyl-1-((2-(trimethylsilyl)ethoxy) methyl)-1H- imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl)-2,4-difluorophenyl)-2-methoxypyr idine-3- sulfonamide [0728] Into an 8 mL vial were added 3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluoroaniline (150 mg, 0.32 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (155 mg, 0.64 mmol, 2 equiv) and pyridine (3 mL). The resulting mixture was stirred for 2 h then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:7) to afford 5-chloro-N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 2-methoxypyridine-3-sulfonamide (140 mg, 65% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 675. Synthesis of Compound 143: 5-chloro-N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl)-2,4- difluorophenyl)-2-methoxypyridine-3-sulfonamide [0729] Into an 8 mL vial were added 5-chloro-N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 2-methoxypyridine-3-sulfonamide (130 mg, 0.19 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 40 °C, then concentrated. The crude product was purified by Prep-HPLC with the following conditions: XBridge Prep C18 OBD Column, 5 µm, 19*150 mm; Mobile Phase: 24-41% MeCN / 0.05% aqueous ammonia; to give 5-chloro- N-[3-[1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6-yl]-2,4-difluorophenyl]-2- methoxypyridine-3-sulfonamide (17 mg, 17% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 545. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 11.33 (s, 1 H), 8.51-8.44 (m, 3H), 8.19 (d, J = 9.4 Hz, 1H), 8.07 (d, J = 2.6 Hz, 1H), 7.35 (td, J = 8.9, 5.9 Hz, 1H), 7.19 (td, J = 9.0, 1.5 Hz, 1H), 6.81 (d, J = 9.4 Hz, 1H), 3.91 (s, 3H), 2.14 (s, 6H). Example 159: Synthesis of N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl)- 2,4-difluorophenyl)-5-fluoro-2-methoxypyridine-3-sulfonamide (Compound 144) Compound 144 Synthesis of 144-a: N-(3-(1-(4,5-dimethyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1 H-imidazol- 2-yl)imidazo [1,5-a]pyridin-6-yl)-2,4-difluorophenyl)-5-fluoro-2-methoxyp yridine-3- sulfonamide [0730] Into an 8 mL vial were added 3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluoroaniline (150 mg, 0.32 mmol, 1 equiv), 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (144 mg, 0.64 mmol, 2 equiv) and pyridine (3 mL). The resulting mixture was stirred for 2 h then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:7) to afford N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 5-fluoro-2-methoxypyridine-3-sulfonamide (130 mg, 62% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 659. Synthesis of Compound 144: N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5-a]pyridin - 6-yl)- 2,4-difluorophenyl)-5-fluoro-2-methoxypyridine-3-sulfonamide [0731] Into an 8 mL vial were added N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 5-fluoro-2-methoxypyridine-3-sulfonamide (120 mg, 0.18 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 40 °C, then concentrated. The crude product was purified by Prep-HPLC with the following conditions: XBridge Prep C18 OBD Column, 5 µm, 19*150 mm; Mobile Phase: 24-41% MeCN / 0.05% aqueous ammonia; to give N-[3- [1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl ]-2,4-difluorophenyl]-5-fluoro- 2-methoxypyridine-3-sulfonamide (32 mg, 33% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 529. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 11.41-11.35 (m, 2H), 8.51 - 8.41 (m, 3H), 8.19 (d, J = 9.4 Hz, 1H), 8.02 (dd, J = 7.4, 3.0 Hz, 1H), 7.35 (td, J = 8.9, 5.9 Hz, 1H), 7.20 (td, J = 9.1, 1.5 Hz, 1H), 6.80 (d, J = 9.4 Hz, 1H), 3.91 (s, 3H), 2.14 (s, 6H). Example 160: Synthesis of N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl)-2,4-difluorophenyl)-5-fluoro-2-methylpyridin e-3-sulfonamide (Compound 145) Compound 145 Synthesis of 145-a: N-(3-(1-(4,5-dimethyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1 H-imidazol- 2-yl)imidazo[1,5-a]pyridin-6-yl)-2,4-difluorophenyl)-5-fluor o-2-methylpyridine-3- sulfonamide [0732] Into an 8 mL vial were added 3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo [1,5-a]pyridin-6-yl]-2,4-difluoroaniline (150 mg, 0.32 mmol, 1 equiv), 5-fluoro-2-methylpyridine-3-sulfonyl chloride (134 mg, 0.64 mmol, 2 equiv) and pyridine (3 mL). The resulting mixture was stirred for 2 h then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:7) to afford N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 5-fluoro-2-methylpyridine-3-sulfonamide (150 mg, 73% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 643. Synthesis of Compound 145: N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5-a]pyridin - 6-yl)-2,4-difluorophenyl)-5-fluoro-2-methylpyridine-3-sulfon amide [0733] Into an 8 mL vial were added N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 5-fluoro-2-methylpyridine-3-sulfonamide (140 mg, 0.22 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 40 °C, then concentrated. The crude product was purified by Prep-HPLC with the following conditions: XBridge Prep C18 OBD Column, 5 µm, 19*150 mm; Mobile Phase: 24-41% MeCN / 0.05% aqueous ammonia; Flow rate: 20 mL/min; to give N-[3-[1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5-a]pyridin -6-yl]-2,4- difluorophenyl]-5-fluoro-2-methylpyridine-3-sulfonamide (41 mg, 37% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 513. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.60 (d, J = 2.9 Hz, 1H), 8.50 (d, J = 6.0 Hz, 2H), 8.18 (d, J = 9.5 Hz, 1H), 7.93 (dd, J = 8.4, 2.9 Hz, 1H), 7.27 (td, J = 9.1, 6.0 Hz, 1H), 7.07 (td, J = 9.1, 1.6 Hz, 1H), 6.87 (d, J = 9.4 Hz, 1H), 2.78 (d, J = 1.2 Hz, 3H), 2.16 (s, 6H). Example 161: Synthesis of 5-chloro-N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl) -2,4-difluorophenyl)-2-methylpyridine-3-sulfonamide (Compound 146) Compound 146 Synthesis of 146-a: 5-chloro-N-(3-(1-(4,5-dimethyl-1-((2-(trimethylsilyl)ethoxy) methyl)-1H- imidazol- 2-yl)imidazo[1,5-a]pyridin-6-yl)-2,4-difluorophenyl)-2-methy lpyridine-3- sulfonamide [0734] Into an 8 mL vial were added 3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluoroaniline (150 mg, 0.32 mmol, 1 equiv), 5-chloro-2-methylpyridine-3-sulfonyl chloride (144 mg, 0.64 mmol, 2 equiv) and pyridine (3 mL). The resulting mixture was stirred for 2 h then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:7) to afford 5-chloro-N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 2-methylpyridine-3-sulfonamide (160 mg, 76% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 659. Synthesis of Compound 146: 5-chloro-N-(3-(1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6-yl) -2,4-difluorophenyl)-2-methylpyridine-3-sulfonamide [0735] Into an 8 mL vial were added 5-chloro-N-[3-[1-(4,5-dimethyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl]-2,4-difluorophenyl]- 2-methylpyridine-3-sulfonamide (160 mg, 0.24 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 40 °C, then concentrated. The crude product was purified by Prep-HPLC with the following conditions: XBridge Prep C18 OBD Column, 5 µm, 19*150 mm; Mobile Phase: 24-41% MeCN / 0.05% aqueous ammonia; Flow rate: 20 mL/min; to give 5-chloro-N-[3-[1-(4,5-dimethyl-1H-imidazol-2-yl)imidazo[1,5- a]pyridin-6- yl]-2,4-difluorophenyl]-2-methylpyridine-3-sulfonamide (34 mg, 26% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 529. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.02 (s, 1H), 8.62 (d, J = 2.4 Hz, 1H), 8.50 (d, J = 6.1 Hz, 2H), 8.17 (d, J = 9.4 Hz, 1H), 8.07 (d, J = 2.4 Hz, 1H), 7.32-7.18 (m, 1H), 7.05 (t, J = 9.3 Hz, 1H), 6.87 (d, J = 9.5 Hz, 1H), 2.77 (s, 3H), 2.15 (s, 6H). Example 162: Synthesis of 5-chloro-N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H- benzo[d]imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl)phenyl)-2-methoxypyridine-3- sulfonamide (Compound 147) Synthesis of 147-a: 5-chloro-N-(2,4-difluoro-3-(1-(1-((2-(trimethylsilyl)ethoxy) methyl)- 4,5,6,7- tetrahydro-1H-benzo[d]imidazol-2-yl)imidazo[1,5-a]pyridin-6- yl)phenyl)-2- methoxypyridine-3-sulfonamide [0736] Into an 8 mL vial were added 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]- 4,5,6,7-tetrahydro-1,3- benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]aniline (150 mg, 0.3 mmol, 1 equiv), 5-chloro-2-methoxypyridine-3-sulfonyl chloride (146 mg, 0.6 mmol, 2 equiv) and pyridine (3 mL). The reaction mixture was stirred for 2 h then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:7) to afford 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy] methyl]-4,5,6,7- tetrahydro-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]p henyl]-2-methoxypyridine-3- sulfonamide (120 mg, 57% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 701. Synthesis of Compound 147: 5-chloro-N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H- benzo[d]imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl)phenyl)-2-methoxypyridine-3- sulfonamide [0737] Into an 8 mL vial were added 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro-1,3-benzod iazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methoxypyridine-3-sulfonamide (110 mg, 0.16 mmol, 1 equiv) and TFA (3 mL). The mixture was stirred for 30 min at 40 °C then concentrated. The crude product was purified by Prep-HPLC with the following conditions: XBridge Prep C18 OBD Column, 5 µm, 19*150 mm; Mobile Phase: 24-41% MeCN / 0.05% aqueous ammonia; Flow rate: 20 mL/min; to give 5-chloro-N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H- benzo[d]imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl)phenyl)-2-methoxypyridine-3- sulfonamide (37 mg, 41% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 571. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 11.38 (s, 1H), 8.45 (s, 2H), 8.37 (d, J = 2.5 Hz, 1H), 8.18 (d, J = 9.4 Hz, 1H), 8.03 (d, J = 2.6 Hz, 1H), 7.35-7.21 (m, 1H), 7.06 (t, J = 9.3 Hz, 1H), 6.80 (d, J = 9.4 Hz, 1H), 3.87 (s, 3H), 2.57-2.51 (m, 4H), 1.79-1.73 (m, 4H). Example 163: Synthesis of N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H- benzo[d]imidazol-2-yl)imidazo [1,5-a]pyridin-6-yl)phenyl)-5-fluoro-2-methoxypyridine- 3-sulfonamide (Compound 148) Compound 148 Synthesis of 148-a: N-(2,4-difluoro-3-(1-(1-((2-(trimethylsilyl)ethoxy)methyl)-4 ,5,6,7- tetrahydro-1H-benzo[d]imidazol-2-yl)imidazo[1,5-a]pyridin-6- yl)phenyl)-5-fluoro-2- methoxypyridine-3-sulfonamide [0738] Into an 8 mL vial were added 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]- 4,5,6,7-tetrahydro-1,3- benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]aniline (150 mg, 0.3 mmol, 1 equiv), 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (136 mg, 0.6 mmol, 2 equiv) and pyridine (3 mL). The resulting mixture was stirred for 2 h at room temperature then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:7) to afford N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]- 4,5,6,7-tetrahydro-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridi n-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (130 mg, 63% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 685. Synthesis of Compound 148: N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H-benzo[d]imidazol - 2-yl)imidazo [1,5-a]pyridin-6-yl)phenyl)-5-fluoro-2-methoxypyridine-3-sul fonamide [0739] Into an 8 mL vial were added N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro-1,3- benzodiazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide (120 mg, 0.18 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 40 °C, then concentrated. The crude product was purified by Prep-HPLC with the following conditions: XBridge Prep C18 OBD Column, 5 µm, 19*150 mm; Mobile Phase: 24-41% MeCN / 0.05% aqueous ammonia; Flow rate: 20 mL/min; to give N-[2,4-difluoro-3-[1-(4,5,6,7-tetrahydro- 1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5 -fluoro-2-methoxypyridine-3- sulfonamide (12 mg, 12% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 555. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.52-10.49 (m, 1H), 8.45 (s, 2H), 8.38-8.32 (m, 1H), 8.18 (d, J = 9.5 Hz, 1H), 7.96 (dd, J = 7.6, 3.0 Hz, 1H), 7.37-7.22 (m, 1H), 7.15-7.06 (m, 1H), 6.84-6.74 (m, 1H), 3.87 (s, 3H), 2.57-2.51 (m, 4H), 1.79-1.72 (m, 4H). Example 164: Synthesis of N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H- benzo[d]imidazol-2-yl) imidazo[1,5-a]pyridin-6-yl)phenyl)-5-fluoro-2-methylpyridine -3- sulfonamide (Compound 149) Compound 149 Synthesis of 149-a: N-(2,4-difluoro-3-(1-(1-((2-(trimethylsilyl)ethoxy)methyl)-4 ,5,6,7- tetrahydro- 1H-benzo[d]imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl)phenyl)- 5-fluoro-2- methylpyridine-3-sulfonamide [0740] Into an 8 mL vial were added 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]- 4,5,6,7-tetrahydro-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridi n-6-yl]aniline (150 mg, 0.3 mmol, 1 equiv), 5-fluoro-2-methylpyridine-3-sulfonyl chloride (136 mg, 0.6 mmol, 2 equiv) and pyridine (3 mL). The reaction was stirred for 2 h at room temperature then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:7) to afford N-(2,4-difluoro-3-(1-(1-((2-(trimethylsilyl)ethoxy)methyl)-4 ,5,6,7-tetrahydro- 1H- benzo[d]imidazol-2-yl)imidazo[1,5-a]pyridin-6-yl)phenyl)-5-f luoro-2-methylpyridine-3- sulfonamide (160 mg, 68% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 669. Synthesis of Compound 159: N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H-benzo[d]imidazol - 2-yl) imidazo[1,5-a]pyridin-6-yl)phenyl)-5-fluoro-2-methylpyridine -3-sulfonamide [0741] Into an 8 mL vial were added N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro-1,3-benzod iazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-5-fluoro-2-methylpyridine-3-sulfonami de (150 mg, 0.22 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 40 °C, then concentrated. The crude product was purified by Prep-HPLC with the following conditions: XBridge Prep C18 OBD Column, 5 µm, 19*150 mm; Mobile Phase: 24-41% MeCN / 0.05% aqueous ammonia; Flow rate: 20 mL/min; to give N-[2,4-difluoro-3-[1-(4,5,6,7-tetrahydro- 1H-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-5 -fluoro-2-methylpyridine-3- sulfonamide (47 mg, 39% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 539. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 11.84 (s, 1H), 8.62 (d, J = 2.9 Hz, 1H), 8.52 - 8.45 (m, 2H), 8.18 (d, J = 9.5 Hz, 1H), 7.93 (dd, J = 8.3, 2.9 Hz, 1H), 7.35-7.21 (m, 1H), 7.16-7.03 (m, 1H), 6.83 (d, J = 9.3 Hz, 1H), 2.77 (d, J = 1.2 Hz, 3H), 2.59-2.53 (m, 4H), 1.80-1.74 (m, 4H).

Example 165: Synthesis of 5-chloro-N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H- benzo[d]imidazol-2 -yl)imidazo[1,5-a]pyridin-6-yl)phenyl)-2-methylpyridine-3- sulfonamide (Compound 150) Compound 150 Synthesis of 150-a: 5-chloro-N-(2,4-difluoro-3-(1-(1-((2-(trimethylsilyl)ethoxy) methyl)- 4,5,6,7-tetrahydro-1H-benzo[d]imidazol-2-yl)imidazo[1,5-a]py ridin-6-yl)phenyl)-2- methylpyridine-3-sulfonamide [0742] Into an 8 mL vial were added 2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]- 4,5,6,7-tetrahydro-1,3-benzodiazol-2-yl)imidazo[1,5-a]pyridi n-6-yl]aniline (150 mg, 0.3 mmol, 1 equiv), 5-chloro-2-methylpyridine-3-sulfonyl chloride (136 mg, 0.6 mmol, 2 equiv) and pyridine (3 mL). The resulting mixture was stirred for 2 h at room temperature then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:7) to afford N-[2,4-difluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]- 4,5,6,7-tetrahydro-1,3-benzodiazol-2-yl)imidazo[1,5-a] pyridin-6-yl]phenyl]-5-chloro-2- methylpyridine-3-sulfonamide (160 mg, 68% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 685. Synthesis of Compound 150: 5-chloro-N-(2,4-difluoro-3-(1-(4,5,6,7-tetrahydro-1H- benzo[d]imidazol-2 -yl)imidazo[1,5-a]pyridin-6-yl)phenyl)-2-methylpyridine-3-su lfonamide [0743] Into an 8 mL vial were added 5-chloro-N-[2,4-difluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]-4,5,6,7-tetrahydro-1,3-benzod iazol-2-yl)imidazo[1,5- a]pyridin-6-yl]phenyl]-2-methylpyridine-3-sulfonamide (140 mg, 0.2 mmol, 1 equiv) and TFA (3 mL). The resulting mixture was stirred for 30 min at 40 °C then concentrated. The crude product was purified by Prep-HPLC with the following conditions: XBridge Prep C18 OBD Column, 5 µm, 19*150 mm; Mobile Phase: 24-41% MeCN / 0.05% aqueous ammonia; Flow rate: 20 mL/min; to give 5-chloro-N-[2,4-difluoro-3-[1-(4,5,6,7-tetrahydro-1H-1,3- benzodiazol-2-yl)imidazo[1,5-a]pyridin-6-yl]phenyl]-2-methyl pyridine-3-sulfonamide (39 mg, 34% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 555. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 11.84 (s, 1H), 8.56 (d, J = 2.5 Hz, 1H), 8.49-8.42 (m, 2H), 8.16 (d, J = 9.4 Hz, 1H), 8.06 (d, J = 2.5 Hz, 1H), 7.21 (td, J = 9.2, 5.9 Hz, 1H), 7.03-6.91 (m, 1H), 6.88-6.78 (m, 1H), 2.77 (s, 3H), 2.58-2.52 (m, 4H), 1.80-1.72 (m, 4H). Example 166: Synthesis of N-[2-chloro-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide (Compound 151) Synthesis of 151-a: 6-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5-a]pyrazine-1- carbonitrile [0744] To a stirred solution of 6-bromoimidazo[1,5-a]pyrazine-1-carbonitrile (350 mg, 1.57 mmol, 1 equiv) and 2-chloro-4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)aniline (639 mg, 2.35 mmol, 1.5 equiv) in dioxane (4 mL) and H ₂ O (0.4 mL) were added Pd(dtbpf)Cl ₂ (102 mg, 0.16 mmol, 0.1 equiv) and K ₃ PO ₄ (999 mg, 4.7 mmol, 3 equiv) in portions at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 5 h at 80 °C, then cooled and quenched with H ₂ O (20 mL). After extraction with EA (3 x 10 mL), the combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 10- 55% MeCN / 0.1% aqueous formic acid; to afford 6-(3-amino-2-chloro-6- fluorophenyl)imidazo[1,5-a]pyrazine-1-carbonitrile (190 mg, 42% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 288 Synthesis of 151-b: 2-chloro-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]pyraz in-6- yl]aniline [0745] To a stirred solution of 6-(3-amino-2-chloro-6-fluorophenyl)imidazo[1,5-a]pyrazine- 1-carbonitrile (180 mg, 0.63 mmol, 1 equiv) in MeOH (4 mL) was added sodium methoxide (452 mg, 8.37 mmol, 13.4 equiv) in portions at 0 °C. The reaction was stirred for 2 h at 50 °C. The mixture was allowed to cool and 2,2-dimethoxyethanamine (66 mg, 0.63 mmol, 1.2 equiv) was added, followed by AcOH (0.15 mL, 2.51 mmol, 5 equiv) dropwise. The resulting mixture was stirred for 4 h at 50 °C, then cooled.6 M aqueous HCl (2.7 mL) was added, then the mixture heated for 5 h at 100 °C. After cooling, H ₂ O (10 mL) was added, and the mixture basified to pH 8 with 30% aqueous NaOH. Following extraction with EA (3 x 5 mL), the combined organics were washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 30-70% MeCN / 0.1% aqueous formic acid; to afford 2-chloro-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]aniline (160 mg, 92% yield) as a brown oil. LCMS (ES, m/z): [M+H] ⁺ : 329 Synthesis of 151-c: 2-chloro-4-fluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl] imidazol-2- yl)imidazo[1,5-a]pyrazin-6-yl]aniline [0746] To a stirred solution of 2-chloro-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]aniline (180 mg, 0.54 mmol, 1 equiv) in THF (4 mL) was added NaH (46 mg, 1.9 mmol, 3.5 equiv) in portions at 0 °C. The resulting mixture was stirred for 0.5 h at 0 °C, then SEMCl (137 mg, 0.82 mmol, 1.5 equiv) was added dropwise over 5 min at 0 °C. The reaction was stirred for 1 h at room temperature, then quenched by the addition of H ₂ O (5 mL). The resulting mixture was extracted with EA (3 x 5 mL), and the combined organics were washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase; 30-80% MeCN / 0.1% aqueous formic acid; to afford 2-chloro-4-fluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl] imidazol-2- yl)imidazo[1,5-a]pyrazin-6-yl]aniline (242 mg, 96% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 459 Synthesis of 151-d: N-[2-chloro-4-fluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]meth yl]imidazol- 2-yl)imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypy ridine-3-sulfonamide [0747] To a stirred solution of 2-chloro-4-fluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]aniline (247 mg, 0.54 mmol, 1 equiv) in pyridine (2 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (182 mg, 0.81 mmol, 1.5 equiv) in DCM (0.5 mL). The reaction was stirred for 1 h at room temperature. The resulting mixture was concentrated, and the residue purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820- 40 μm, 120 g; mobile phase: 30-80% MeCN / 0.1% aqueous formic acid; to afford N-[2- chloro-4-fluoro-3-[1-(1-[[2-(trimethylsilyl)ethoxy]methyl]im idazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide (135 mg, 39% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 648 Synthesis of Compound 151: N-[2-chloro-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonam ide [0748] Into a 40 mL vial was placed N-[2-chloro-4-fluoro-3-[1-(1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (140 mg, 0.22 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 2 h at room temperature, then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 30-75% MeCN / 0.1% aqueous formic acid; to give N-[2-chloro-4-fluoro-3-[1-(1H-imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide (50 mg, 45% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 518 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.71 (s, 1H), 10.41 (s, 1H), 9.56 (d, J = 2.4 Hz, 1H), 8.64 (d, J = 0.6 Hz, 1H), 8.53 (d, J = 1.7 Hz, 1H), 8.46 (d, J = 3.0 Hz, 1H), 8.01 (dd, J = 7.3, 3.0 Hz, 1H), 7.49 (dd, J = 8.9, 5.7 Hz, 1H), 7.40 (t, J = 8.8 Hz, 1H), 7.17 (s, 2H), 3.88 (s, 3H). Example 167: Synthesis of (6R)-6-[2-chloro-6-fluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyrid ine-1-carboxamide (first eluting isomer, 35 mg, stereochemistry randomly assigned) and (6S)-6-[2-chloro-6- fluoro-3-(5-fluoro-2-methoxypyridine-3-sulfonamido)phenyl]-N -methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (Compounds 152-1 & 152-2) Compound 152-1 Compound 152-2 Synthesis of 152-a: 6-(3-amino-2-chloro-6-fluorophenyl)-N-methyl-5,6,7,8-imidazo [1,5- a]pyridine-1-carboxamide [0749] To a solution of 6-(3-amino-2-chloro-6-fluorophenyl)-N-methylimidazo[1,5- a]pyridine-1-carboxamide (400 mg, 1.2 mmol, 1 equiv) in 10 mL MeOH and 2M aqueous HCl (1 mL) was added PtO ₂ (28 mg) in a pressure tank. The mixture was hydrogenated at 50 °C under 10 atm of hydrogen pressure for 2 hr, then filtered through a Celite pad and concentrated. The residue was purified by silica gel column chromatography, eluting with PE:EA(1:1) to afford 6-(3-amino-2-chloro-6-fluorophenyl)-N-methyl-5,6,7,8-imidazo [1,5- a]pyridine-1-carboxamide (120 mg, 30% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 323 Synthesis of Compounds 152-1 & 152-2: (6R)-6-[2-chloro-6-fluoro-3-(5-fluoro-2- methoxypyridine-3-sulfonamido)phenyl]-N-methyl-5H,6H,7H,8H-i midazo[1,5-a]pyridine-1- carboxamide (first eluting isomer, 35 mg, stereochemistry randomly assigned) and (6S)-6-[2- chloro-6-fluoro-3-(5-fluoro-2-methoxypyridine-3-sulfonamido) phenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide [0750] To a solution of 6-(3-amino-2-chloro-6-fluorophenyl)-N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (120 mg, 0.3 mmol, 1 equiv) and pyridine (88 mg, 1 mmol, 3 equiv) in DCM (5 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (125 mg, 0.5 mmol, 1.5 equiv). The reaction mixture was stirred for 1 hr, then concentrated. The residue was purified by column chromatography over silica gel (eluent: PE:EA =2:1) to afford 6-[2-chloro-6-fluoro-3-(5-fluoro-2-methoxypyridine-3-sulfona mido)phenyl]-N- methyl-5,6,7,8-imidazo[1,5-a]pyridine-1-carboxamide (80 mg, 42% yield) as a white solid. The racemic mixture of 6-[2-chloro-6-fluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyrid ine-1-carboxamide (100 mg) was separated by chiral HPLC using the following conditions: Column, CHIRALAPLC,IC, 250 x 20 mm, 5 µm; Mobile Phase: 50% EtOH / Hexane; to give (6R)-6- [2-chloro-6-fluoro-3-(5-fluoro-2-methoxypyridine-3-sulfonami do)phenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (first eluting isomer, 35 mg, stereochemistry randomly assigned) and (6S)-6-[2-chloro-6-fluoro-3-(5-fluoro-2- methoxypyridine-3-sulfonamido)phenyl]-N-methyl-5H,6H,7H,8H-i midazo[1,5-a]pyridine-1- carboxamide (second eluting isomer, 33 mg, stereochemistry assigned as opposite to other isomer) as white solids. First eluting isomer: LCMS (ES, m/z): [M+H] ⁺ : 512 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.30 (s, 1H), 8.48 (d, J = 3.0 Hz, 1H), 7.99 (dd, J = 7.3, 3.0 Hz, 1H), 7.75 (d, J = 4.9 Hz, 1H), 7.56 (s, 1H), 7.35-7.21 (m, 2H), 4.26 (dd, J = 12.5, 5.4 Hz, 1H), 4.12 (t, J = 11.9 Hz, 1H), 3.85 (s, 3H), 3.69 (s, 1H), 3.39 (d, J = 3.0 Hz, 1H), 2.86 (ddd, J = 17.6, 11.7, 5.9 Hz, 1H), 2.71 (d, J = 4.8 Hz, 3H), 2.25 (d, J = 15.2 Hz, 1H), 1.98 (d, J = 12.7 Hz, 1H). Second eluting isomer : LCMS (ES, m/z): [M+H] ⁺ : 512 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.30 (s, 1H), 8.47 (d, J = 3.0 Hz, 1H), 7.99 (dd, J = 7.3, 3.0 Hz, 1H), 7.75 (q, J = 4.7 Hz, 1H), 7.56 (s, 1H), 7.38-7.17 (m, 2H), 4.26 (dd, J = 12.4, 5.4 Hz, 1H), 4.12 (t, J = 11.9 Hz, 1H), 3.85 (s, 3H), 3.69 (s, 1H), 3.39 (d, J = 3.0 Hz, 1H), 2.86 (ddd, J = 17.7, 11.8, 6.1 Hz, 1H), 2.71 (d, J = 4.8 Hz, 3H), 2.24 (d, J = 13.7 Hz, 1H), 1.98 (d, J = 13.2 Hz, 1H). Example 168: Synthesis of methyl 2-[6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]imidazo[1,5-a]pyrazin-1-yl]-3H-1,3-benzod iazole-5-carboxylate (Compound 153) Compound 153 Synthesis of 153-a: methyl 3-amino-4-[6-(3-amino-2,6-difluorophenyl)imidazo[1,5- a]pyrazine-1-amido]benzoate [0751] Into a 250 mL 3-necked round-bottom flask was placed 6-(3-amino-2,6- difluorophenyl)imidazo[1,5-a]pyrazine-1-carboxylic acid (2 g, 6.9 mmol, 1 equiv), methyl 3,4-diaminobenzoate (1.15 g, 6.9 mmol, 1 equiv), HATU (3.93 g, 10 mmol, 1.5 equiv), DIEA (1.8 g, 13.8 mmol, 2 equiv) and DMF (100 mL). The resulting solution was stirred for 2 h then quenched by the addition of water (150 mL). The solid formed was collected by filtration and dried to give methyl 3-amino-4-[6-(3-amino-2,6-difluorophenyl)imidazo[1,5- a]pyrazine-1-amido]benzoate (2.3 g, 69% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 439. Synthesis of 153-b: methyl 2-[6-(3-amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazin-1-yl] - 3H-1,3-benzodiazole-5-carboxylate [0752] Into a 50 mL 3-necked round-bottom flask was placed methyl 3-amino-4-[6-(3- amino-2,6-difluorophenyl)imidazo[1,5-a]pyrazine-1-amido]benz oate (2.3 g, 5.3 mmol, 1 equiv) in AcOH (15 mL). The resulting solution was stirred for 12 h at 80 °C then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: sunfire Prep C18 OBD Column, 50*250 mm 5 µm 10 nm; Mobile Phase: 10-45% MeCN / 0.1% aqueous formic acid; to give methyl-2-[6-(3-amino-2,6- difluorophenyl)imidazo[1,5-a]pyrazin-1-yl]-3H-1,3-benzodiazo le-5-carboxylate (1.0 g, 43% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 421 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.43 (s, 1H), 9.82 (d, J = 1.6 Hz, 1H), 8.83 (s, 1H), 8.73 (s, 1H), 8.23 (d, J = 47.0 Hz, 1H), 7.74 (d, J = 71.1 Hz, 2H), 7.04-6.82 (m, 2H), 5.18 (s, 2H), 3.90 (s, 3H). Synthesis of Compound 153: methyl 2-[6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]imidazo[1,5-a]pyrazin-1-yl]-3H-1,3-benzod iazole-5-carboxylate [0753] Into a 25 mL 3-necked round-bottom flask was placed methyl 2-[6-(3-amino-2,6- difluorophenyl)imidazo[1,5-a]pyrazin-1-yl]-3H-1,3-benzodiazo le-5-carboxylate (100 mg, 0.24 mmol, 1 equiv), DCM (5 mL), pyridine (0.5 mL) and 5-fluoro-2-methoxypyridine-3- sulfonyl chloride (107 mg, 0.48 mmol, 2 equiv). The resulting solution was stirred for 12 h at 45 °C then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: sunfire Prep C18 OBD Column, 50*250 mm 5 µm 10 nm, Mobile Phase 25-65% MeCN / 0.1% aqueous formic acid; to give methyl 2-[6-[2,6-difluoro-3-(5- fluoro-2-methoxypyridine-3-sulfonamido)phenyl]imidazo[1,5-a] pyrazin-1-yl]-3H-1,3- benzodiazole-5-carboxylate (55 mg, 37% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 610 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.44 (s, 1H), 10.46 (s, 1H), 9.79 (d, J = 1.6 Hz, 1H), 8.84 (s, 1H), 8.73 (d, J = 1.6 Hz, 1H), 8.48 (d, J = 3.0 Hz, 1H), 8.19 (s, 1H), 8.05 (dd, J = 7.3, 3.0 Hz, 1H), 7.87 (d, J = 8.2 Hz, 1H), 7.44 (td, J = 8.8, 5.8 Hz, 1H), 7.33-7.21 (m, 1H), 3.91 (s, 3H), 3.90 (s, 3H). Example 169: Synthesis of (6S)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methyl-5H,6H,8H-imidazo[4,3-c][1,4]oxazine -1-carboxamide and (6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-dif luorophenyl]-N-methyl- 5H,6H,8H-imidazo[4,3-c][1,4]oxazine-1-carboxamide hydrochloride (Compounds 154-1 & 154-2) Synthesis of 154-a: 3-bromo-2,4-difluoro-N,N-bis[(4-methoxyphenyl)methyl]aniline [0754] Into a 500 mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, cooled in an ice bath, was placed 3-bromo-2,4-difluoroaniline (10 g, 48 mmol, 1 equiv), DMF (200 mL), 60% NaH (3.46 g, 144 mmol, 3 equiv) and PMBCl (22.6 g, 144 mmol, 3 equiv). The resulting solution was stirred for 5 h at 0 °C. The reaction was quenched by the addition of water (300 mL) and extracted with ethyl acetate (2 x 200 mL). The combined organics were washed with 200 ml of water and 200 mL of brine, dried over anhydrous sodium sulfate and concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:3) to give 3-bromo-2,4-difluoro-N,N-bis[(4- methoxyphenyl)methyl]aniline (15.6 g, 72% yield) as a light yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 448 Synthesis of 154-b: 1-(3-[bis[(4-methoxyphenyl)methyl]amino]-2,6-difluorophenyl) -2- chloroethanone [0755] Into a 500 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 3-bromo-2,4-difluoro-N,N-bis[(4- methoxyphenyl)methyl]aniline (15.6 g, 34.8 mmol, 1 equiv) in THF (300 mL).2.5 M n-BuLi in hexanes (17 mL, 42.5 mmol, 1.2 equiv) was added dropwise with stirring at -78 °C, and the reaction stirred for 1 h at low temperature. To the resultant mixture was added a solution of 2-chloro-N-methoxy-N-methylacetamide (6.7 g, 48.7 mmol, 1.4 equiv) in THF (6 mL) dropwise with stirring at -78 °C. This mixture was allowed to warm to room temperature over 5 h. The reaction was quenched by the addition of water (300 mL), then extracted with ethyl acetate (3 x 200 mL). The combined organics were washed with 300 ml of water and 300 mL of brine, dried over anhydrous sodium sulfate and concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:2) to give 1-(3-[bis[(4- methoxyphenyl)methyl]amino]-2,6-difluorophenyl)-2-chloroetha none (7 g, 45% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 446 Synthesis of 154-c: 4,5-dimethyl 1-[2-(3-[bis[(4-methoxyphenyl)methyl]amino]-2,6- difluorophenyl)-2-oxoethyl]imidazole-4,5-dicarboxylate [0756] Into a 250 mL 3-necked round-bottom flask was placed 1-(3-[bis[(4- methoxyphenyl)methyl]amino]-2,6-difluorophenyl)-2-chloroetha none (4 g, 8.9 mmol, 1 equiv), MeCN (100 mL), 4,5-dimethyl 1H-imidazole-4,5-dicarboxylate (1.8 g, 9.9 mmol, 1.1 equiv) and K ₂ CO ₃ (2.5 g, 17.9 mmol, 2 equiv). The resulting solution was stirred overnight at 80 °C then cooled and filtered. The filtrate was concentrated and applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:2).4,5-Dimethyl 1-[2-(3-[bis[(4- methoxyphenyl)methyl]amino]-2,6-difluorophenyl)-2-oxoethyl]i midazole-4,5-dicarboxylate (3 g, 56% yield) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 594 Synthesis of 154-d: methyl 1-[2-(3-[bis[(4-methoxyphenyl)methyl]amino]-2,6- difluorophenyl)-2-hydroxyethyl]-5-(hydroxymethyl)imidazole-4 -carboxylate [0757] Into a 250 mL 3-necked round-bottom flask was placed 4,5-dimethyl 1-[2-(3-[bis[(4- methoxyphenyl)methyl]amino]-2,6-difluorophenyl)-2-oxoethyl]i midazole-4,5-dicarboxylate (3 g, 5.1 mmol, 1 equiv), THF (60 mL), NaBH ₄ (0.57 g, 15.2 mmol, 3 equiv) and MeOH (10 mL). The resulting solution was stirred for 5 h then concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:1). Methyl 1-[2-(3-[bis[(4- methoxyphenyl)methyl]amino]-2,6-difluorophenyl)-2-hydroxyeth yl]-5- (hydroxymethyl)imidazole-4-carboxylate (2 g, 70% yield) was isolated as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 568 Synthesis of 154-e: methyl 6-(3-[bis[(4-methoxyphenyl)methyl]amino]-2,6-difluorophenyl) - 5H,6H,8H-imidazo[4,3-c][1,4]oxazine-1-carboxylate [0758] Into a 100 mL round-bottom flask was placed methyl 1-[2-(3-[bis[(4- methoxyphenyl)methyl]amino]-2,6-difluorophenyl)-2-hydroxyeth yl]-5- (hydroxymethyl)imidazole-4-carboxylate (1 g, 1.8 mmol, 1 equiv), DCM (50 mL), TMAD (0.46 g, 2.7 mmol, 1.5 equiv) and PPh ₃ (0.69 g, 2.6 mmol, 1.5 equiv). The resulting solution was stirred overnight, then concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:2) to give methyl 6-(3-[bis[(4- methoxyphenyl)methyl]amino]-2,6-difluorophenyl)-5H,6H,8H-imi dazo[4,3-c][1,4]oxazine- 1-carboxylate (160 mg, 17% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 550 Synthesis of 154-f: 6-(3-[bis[(4-methoxyphenyl)methyl]amino]-2,6-difluorophenyl) -N- methyl-5H,6H,8H-imidazo[4,3-c][1,4]oxazine-1-carboxamide [0759] To a stirred solution of methyl 6-(3-[bis[(4-methoxyphenyl)methyl]amino]-2,6- difluorophenyl)-5H,6H,8H-imidazo[4,3-c][1,4]oxazine-1-carbox ylate (160 mg, 0.29 mmol, 1 equiv) in MeOH (5 mL) was added 33% aqueous methylamine solution (5 mL). The reaction was stirred for 24 h, then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 µm, 120 g; mobile phase: 25-95% MeCN / 0.1% aqueous formic acid; to give 6-(3-[bis[(4- methoxyphenyl)methyl]amino]-2,6-difluorophenyl)-N-methyl-5H, 6H,8H-imidazo[4,3- c][1,4]oxazine-1-carboxamide (140 mg, 88% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 549. Synthesis of 154-g: 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,8H-imidazo[4,3 - c][1,4]oxazine-1-carboxamide [0760] To a stirred solution of 6-(3-[bis[(4-methoxyphenyl)methyl]amino]-2,6- difluorophenyl)-N-methyl-5H,6H,8H-imidazo[4,3-c][1,4]oxazine -1-carboxamide (135 mg, 0.25 mmol, 1 equiv) in DCM (3 mL) was added TFA (1 mL) dropwise at 0 °C. The resulting mixture was stirred for 6 h at room temperature then was concentrated. The residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 µm, 120 g; mobile phase: 20-70% MeCN / 0.1% aqueous formic acid; to give 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,8H-imidazo[4,3 -c][1,4]oxazine-1- carboxamide (60 mg, 79% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 309. Synthesis of Compounds 154-1 & 154-2: (6S)-6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-methyl-5H,6H,8H-imidazo[4 ,3-c][1,4]oxazine-1- carboxamide and (6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methyl-5H,6H,8H-imidazo[4,3-c][1,4]oxazine -1-carboxamide hydrochloride [0761] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methyl-5H,6H,8H- imidazo[4,3-c][1,4]oxazine-1-carboxamide (55 mg, 0.18 mmol, 1 equiv) in pyridine (2 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (130 mg, 0.54 mmol, 3 equiv) in portions at room temperature. The resulting mixture was stirred for 2 days then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 20-50% MeCN / 0.1% aqueous formic acid to give the racemic product. The enantiomers were separated by Chiral-Prep- HPLC with the following conditions: Column, CHIRALPAK IC, 20*250 mm, 5 μm; Mobile Phase: 30% EtOH / Hexane (containing 0.1% DEA); to give (6S)-6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-methyl- 5H,6H,8H-imidazo[4,3- c][1,4]oxazine-1-carboxamide (first eluting isomer, 3.4 mg, 4% yield, stereochemistry randomly assigned) and (6R)-6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methyl-5H,6H,8H-imidazo[4,3-c][1,4]oxazine -1-carboxamide (second eluting isomer, 4.1 mg, 4% yield, stereochemistry assigned as opposite to other isomer) as white solids. LCMS (ES, m/z): [M+H] ⁺ : 514 for both isomers ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.39 (s, 1H), 8.50 (d, J = 2.6 Hz, 1H), 8.05 (d, J = 2.6 Hz, 1H), 7.87 (d, J = 4.9 Hz, 1H), 7.68 (s, 1H), 7.42-7.28 (m, 1H), 7.12 (t, J = 9.5 Hz, 1H), 5.29- 5.13 (m, 2H), 5.00 (d, J = 15.9 Hz, 1H), 4.35 (dd, J = 12.6, 3.6 Hz, 1H), 4.19 (t, J = 11.7 Hz, 1H), 3.91 (s, 3H), 2.72 (d, J = 4.8 Hz, 3H). ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.39 (s, 1H), 8.49 (s, 1H), 8.05 (d, J = 2.6 Hz, 1H), 7.87 (d, J = 5.0 Hz, 1H), 7.68 (s, 1H), 7.34 (d, J = 6.6 Hz, 1H), 7.11 (t, J = 9.3 Hz, 1H), 5.21 (t, J = 13.8 Hz, 2H), 5.00 (d, J = 16.0 Hz, 1H), 4.35 (d, J = 11.5 Hz, 1H), 4.20 (t, J = 11.9 Hz, 1H), 3.90 (s, 3H), 2.72 (d, J = 4.8 Hz, 3H).

Example 170: Synthesis of (6R)-6-[6-chloro-2-fluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyrid ine-1-carboxamide and (6S)-6-[6-chloro-2-fluoro-3-(5-fluoro-2-methoxypyridine-3-su lfonamido)phenyl]-N- methyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (Compounds 155-1 & 155- 2) Synthesis of 155-a: methyl 6-(3-amino-6-chloro-2-fluorophenyl)imidazo[1,5-a]pyridine-1- carboxylate [0762] To a stirred mixture of methyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)imidazo[1,5-a]pyridine-1-carboxylate (3.5 g, 12 mmol, 1 equiv) in dioxane (70 mL) and H ₂ O (10 mL) was added 3-bromo-4-chloro-2-fluoroaniline (2.8 g, 13 mmol, 1.1 equiv), Pd(dppf)Cl ₂ (0.7 g, 0.9 mmol, 0.08 equiv) and K ₂ CO ₃ (3.2 g, 23 mmol, 2 equiv). The reaction was stirred for 4 h at 90 °C under nitrogen atmosphere. The resulting solution was cooled and diluted with 50 mL of H ₂ O, then extracted with 3 x 50 mL of ethyl acetate. The combined organics were dried over anhydrous sodium sulfate and concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 30-80% MeCN / 0.1% aqueous formic acid; to afford methyl 6-(3-amino-6-chloro-2-fluorophenyl)imidazo[1,5-a]pyridine-1- carboxylate (3 g, 81% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 320 Synthesis of 155-b: methyl 6-(3-amino-2-fluorophenyl)-5H,6H,7H,8H-imidazo[1,5- a]pyridine-1-carboxylate [0763] To a stirred mixture of methyl 6-(3-amino-6-chloro-2-fluorophenyl)imidazo[1,5- a]pyridine-1-carboxylate (2 g, 6.3 mmol, 1 equiv) in MeOH (120 mL) was added 10% Pd/C (2 g). The resulting suspension was stirred for 16 h at 80 °C under H ₂ atmosphere (20 atm). The mixture was cooled and the solids removed by filtration. The filtrate was concentrated, and the residue purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 5-55% MeCN / 0.1% aqueous formic acid; to afford methyl 6-(3-amino-2-fluorophenyl)-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxylate (807 mg, 45% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 290 Synthesis of 155-c and 155-cA: methyl 6-(3-amino-6-chloro-2-fluorophenyl)-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxylate and 6-(3-amino-4-chloro-2-fluorophenyl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxylate [0764] To a stirred mixture of methyl 6-(3-amino-2-fluorophenyl)-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxylate (807 mg, 2.8 mmol, 1 equiv) in DMF (55 mL) was added NCS (410 mg, 3.1 mmol, 1.1 equiv). The reaction was stirred for 12 h at 50 °C, then cooled and diluted with 20 mL of H ₂ O. The resulting mixture was extracted with 3 x 20 mL of ethyl acetate. The combined organics were washed with brine (2 x 100 mL), dried over anhydrous sodium sulfate and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 16-33% MeCN / 0.1% aqueous formic acid; to afford methyl 6-(3-amino-6-chloro-2- fluorophenyl)-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxyla te (530 mg, 59% yield) and 6-(3-amino-4-chloro-2-fluorophenyl)-5H,6H,7H,8H-imidazo[1,5- a]pyridine-1-carboxylate (237 mg, 26% yield) as white solids. LCMS (ES, m/z): [M+H] ⁺ : 324 Synthesis of 155-d: 6-(3-amino-6-chloro-2-fluorophenyl)-N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide [0765] Into a 40 mL vial was placed methyl 6-(3-amino-6-chloro-2-fluorophenyl)- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxylate (287 mg, 0.9 mmol, 1 equiv) and 33% methylamine solution in EtOH (20 mL). The solution was stirred for 3 days at 80 °C then concentrated to give crude 6-(3-amino-6-chloro-2-fluorophenyl)-N-methyl-5H,6H,7H,8H- imidazo[1,5-a]pyridine-1-carboxamide (287 mg) as brown oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 323 Synthesis of Compounds 155-1 & 155-2 : (6R)-6-[6-chloro-2-fluoro-3-(5-fluoro-2- methoxypyridine-3- sulfonamido)phenyl]-N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyrid ine-1- carboxamide and (6S)-6-[6-chloro-2-fluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyrid ine-1-carboxamide [0766] Into a 40 mL vial was placed 6-(3-amino-6-chloro-2-fluorophenyl)-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (287 mg, 0.9 mmol, 1 equiv), pyridine (5 mL) and 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (602 mg, 2.7 mmol, 3 equiv). The solution was stirred for 2 h then diluted with water (10 mL). The resulting mixture was extracted with EA (3 x 10 mL), and the combined organics washed with brine (2 x 5 mL), dried over anhydrous Na ₂ SO ₄ then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm: Mobile Phase: 20-50% MeCN / 0.1% aqueous formic acid to give the racemic product. The enantiomers were separated by chiral-prep-HPLC with the following conditions: Column, CHIRALPAK IE, 3*25 cm, 5 µm; Mobile Phase: 5% MeOH / MTBE; Flow rate: 35 mL/min; to give (6R)-6-[6-chloro-2-fluoro-3-(5-fluoro-2-methoxypyridine-3-su lfonamido)phenyl]-N- methyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide (retention time 22 mins, 50 mg, 11% yield, stereochemistry randomly assigned) and (6S)-6-[6-chloro-2-fluoro-3-(5-fluoro-2- methoxypyridine-3-sulfonamido) phenyl]-N-methyl-5H,6H,7H,8H-imidazo[1,5-a]pyridine-1- carboxamide (retention time 28 mins, 50 mg, 11% yield, stereochemistry assigned as opposite to other isomer) as white solids. LCMS (ES, m/z): [M+H] ⁺ : 512 for both isomers (6R)-6-[6-chloro-2-fluoro-3-(5-fluoro-2-methoxypyridine-3-su lfonamido)phenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.50 (s, 1H), 8.38 (d, J = 3.0 Hz, 1H), 7.95 (dd, J = 7.5, 3.0 Hz, 1H), 7.75 (q, J = 4.7 Hz, 1H), 7.57 (s, 1H), 7.25-7.22 (m, 2H), 4.26 (dd, J = 12.3, 5.2 Hz, 1H), 4.02 (t, J = 11.9 Hz, 1H), 3.85 (s, 3H), 3.63 (m, 2H), 2.85 (ddd, J = 17.7, 11.7, 6.0 Hz, 1H), 2.72 (d, J = 4.7 Hz, 3H), 2.16 (d, J = 13.0 Hz, 1H), 1.96 (s, 1H). (6S)-6-[6-chloro-2-fluoro-3-(5-fluoro-2-methoxypyridine-3-su lfonamido)phenyl]-N-methyl- 5H,6H,7H,8H-imidazo[1,5-a]pyridine-1-carboxamide ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.46 (s, 1H), 8.43 (s, 1H), 7.98 (d, J = 7.4 Hz, 1H), 7.75 (d, J = 4.9 Hz, 1H), 7.56 (s, 1H), 7.26 (d, J = 6.5 Hz, 2H), 4.26 (dd, J = 12.3, 5.2 Hz, 1H), 4.00 (t, J = 11.9 Hz, 1H), 3.87 (s, 3H), 3.64 (s, 1H), 2.94 – 2.79 (m, 1H), 2.72 (d, J = 4.7 Hz, 3H), 2.54 (s, 1H), 2.19-2.05 (m, 1H), 1.96 (s, 1H).

Example 171: Synthesis of N-[2,4-difluoro-3-[1-(4-phenyl-1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide (Compound 156) Synthesis of 156-a: 5-phenyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole and 4-phenyl-1- ((2- (trimethylsilyl) ethoxy)methyl)-1H-imidazole [0767] To a stirred solution of 4-phenyl-1H-imidazole (4 g, 28 mmol, 1 equiv) in THF (140 mL) was added NaH (2 g, 55 mmol, 2 equiv, 60%) in portions at 0 °C. To this was then added SEMCl (6.9 g, 42 mmol, 1.5 equiv) dropwise at 0 °C. The reaction was stirred for additional 1 h in the ice bath, then quenched with water/ice (200 mL). The resulting mixture was extracted with EtOAc (3 x 200 mL), and the combined organics were washed with water (3 x 100 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford 5-phenyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazole and 4-phenyl-1-((2-(trimethylsilyl) ethoxy)methyl)- 1H-imidazole mixture (6.9 g, 91% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 275 Synthesis of 156-b: 2,4-difluoro-3-[1-(4-phenyl-1- [[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo [1,5-a]pyrazin-6-yl]aniline and 2,4- difluoro-3-[1-(5-phenyl-1- [[2-(trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]aniline [0768] To a stirred solution of 4-phenyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazole and 5-phenyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazole mixture (1.4 g, 5 mmol, 5 equiv) in THF (8 mL) was added n-BuLi in hexanes (32 mL, 81 mmol, 5 equiv, 2.5 M) dropwise at -78 °C and this was stirred at low temperature for 30 min. To the solution was added ZnCl ₂ (5 mL, 5 mmol, 5 equiv, 1 M in Et ₂ O) dropwise at -78 °C, and the resulting mixture was stirred to room temperature for 30 min. Pd(PPh ₃ ) ₄ (230 mg, 0.2 mmol, 0.2 equiv) and 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyrazin-6-yl]aniline (372 mg, 1 mmol, 1 equiv, in THF) were added, and this mixture heated to 60 °C for 1 hr. The reaction was cooled to 0 °C and quenched with aqueous NH ₄ Cl (saturated, 30 ml). The resulting mixture was extracted with EA (3 x 30 ml), and the combined organics washed with brine (30 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EA (1/1) to afford 2,4-difluoro-3-[1-(4-phenyl-1- [[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]aniline and 2,4- difluoro-3-[1-(5-phenyl-1-[[2-(trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]aniline mixture (290 mg, 66% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 519 Synthesis of 156-c: N-[2,4-difluoro- 3-[1-(4-phenyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyrazin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide and N-[2,4-difluoro-3- [1- (5-phenyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyrazin-6-yl]phenyl]- 5-fluoro-2- methoxypyridine-3-sulfonamide [0769] To a stirred solution of 2,4-difluoro-3-[1-(4-phenyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]aniline and 2,4- difluoro-3-[1-(5-phenyl-1-[[2-(trimethylsilyl)ethoxy]methyl] imidazol-2-yl)imidazo[1,5-a] pyrazin-6-yl]aniline mixture (100 mg, 0.2 mmol, 1 equiv) in pyridine (3 mL) was added 5- fluoro-2-methoxypyridine-3-sulfonyl chloride (65 mg, 0.3 mmol, 1.5 equiv). The resulting mixture was stirred for 2 h then concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20-70% MeCN / 0.1% aqueous formic acid; to give N-[2,4-difluoro- 3-[1-(4- phenyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imi dazo[1,5-a]pyrazin-6- yl]phenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide and N-[2,4-difluoro-3-[1-(5-phenyl-1- [[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl) imidazo[1,5-a]pyrazin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide mixture (95 mg, 70% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 708 Synthesis of Compound 156: N-[2,4-difluoro-3-[1-(4-phenyl-1H-imidazol-2-yl)imidazo[1,5- a]pyrazin-6-yl]phenyl]-5- fluoro-2-methoxypyridine-3-sulfonamide [0770] To a stirred solution of N-[2,4-difluoro-3-[1-(5-phenyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide and N-[2,4-difluoro-3-[1-(4-phenyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]phenyl]-5-fluoro-2- methoxypyridine-3-sulfonamide (95 mg, 0.1 mmol, 1 equiv, mixture) in DCM (6 mL) was added TFA (2 mL). The resulting mixture was stirred for 5 h then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 µm; Mobile Phase: 5-60% MeCN / 0.1% aqueous formic acid; to give N- [2,4-difluoro-3-[1-(4-phenyl-1H-imidazol-2-yl)imidazo[1,5-a] pyrazin-6-yl]phenyl]-5-fluoro- 2-methoxypyridine-3-sulfonamide (60 mg, 77% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 578 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 13.01 (s, 1H), 10.45 (s, 1H), 9.80-9.49 (s, 1H), 8.70 (s, 1H), 8.58 (d, 1H), 8.44 (d, J = 3.0 Hz, 1H), 8.10-7.83 (m, 3H), 7.80-7.52 (d, J = 7.7 Hz, 1H), 7.40 (m, 3H), 7.22 (m, 2H), 3.91 (s, 3H). Example 172: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-isopropylimidazo[1,5-a]pyrazine-1-carboxam ide (Compound 157) Synthesis of Compound 157: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-isopropylimidazo[1,5-a]pyrazine-1-carboxam ide [0771] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added isopropylamine (35 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv) at room temperature. The resulting mixture was stirred for 1 h then diluted with H ₂ O (50 mL). This was extracted with EA (3 x 50 mL), and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: Sunfire Prep C18 OBD, 50*250 mm 5 µm 10 nm; Mobile Phase: 15-50% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-isoprop ylimidazo[1,5-a]pyrazine-1- carboxamide (90 mg, 42% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 537 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.66 (d, J = 4.0 Hz, 2H), 8.50 (d, J = 2.6 Hz, 1H), 8.23-8.03 (m, 2H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.25 (td, J = 9.1, 1.6 Hz, 1H), 4.25-4.08 (m, 1H), 3.92 (s, 3H), 1.22 (d, J = 6.6 Hz, 6H). Example 173: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(2-methylpropyl)imidazo[1,5-a]pyrazine-1-c arboxamide (Compound 158) Synthesis of Compound 158: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(2-methylpropyl)imidazo[1,5-a]pyrazine-1-c arboxamide [0772] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added isobutylamine (44 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1 h at room temperature. The resulting mixture was diluted with H ₂ O (50 mL) and extracted with EA (3 x 50 mL). The combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: Sunfire Prep C18 OBD, 50*250 mm 5 µm 10 nm; Mobile Phase: 15-50% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-(2-meth ylpropyl)imidazo[1,5- a]pyrazine-1-carboxamide (95 mg, 42% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 551 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.67 (d, J = 3.3 Hz, 2H), 8.50 (d, J = 2.6 Hz, 1H), 8.41 (t, J = 6.2 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.25 (td, J = 9.1, 1.6 Hz, 1H), 3.92 (s, 3H), 3.23-3.09 (m, 2H), 1.89 (dq, J = 13.6, 6.9 Hz, 1H), 0.90 (d, J = 6.7 Hz, 6H). Example 174: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(2,2,2-trifluoroethyl)imidazo[1,5-a]pyrazi ne-1-carboxamide (Compound 159) Synthesis of Compound 160: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(2,2,2-trifluoroethyl)imidazo[1,5-a]pyrazi ne-1-carboxamide [0773] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added 2,2,2-trifluoroethylamine (59 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1 h at room temperature, then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL) and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: Sunfire Prep C18 OBD, 50*250 mm 5 µm 10 nm; Mobile Phase: 10-30% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-(2,2,2- trifluoroethyl)imidazo[1,5- a]pyrazine-1-carboxamide (105 mg, 45% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 577 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 9.52 (d, J = 1.6 Hz, 1H), 9.03 (t, J = 6.6 Hz, 1H), 8.72 (d, J = 2.6 Hz, 2H), 8.51 (d, J = 2.6 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.43 (td, J = 8.8, 5.8 Hz, 1H), 7.26 (td, J = 9.1, 1.6 Hz, 1H), 4.10 (dq, 2H), 3.92 (s, 3H).

Example 175: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-fluoro- N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 160) Synthesis of 160-a: tert-butyl N-(3-bromo-6-chloropyrazin-2-yl)-N-(tert- butoxycarbonyl)carbamate [0774] To a stirred solution of 3-bromo-6-chloropyrazin-2-amine (20 g, 96 mmol, 1 equiv) in DCM (400 mL) was added DMAP (5.8 g, 48 mmol, 0.5 equiv) and (Boc) ₂ O (52 g, 240 mmol, 2.5 equiv). The resulting mixture was stirred overnight then washed with brine (2 x 600 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (10:1) to afford tert-butyl N-(3-bromo-6- chloropyrazin-2-yl)-N-(tert-butoxycarbonyl)carbamate (34 g, 87% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 408 Synthesis of 160-b: methyl 5-[bis(tert-butoxycarbonyl)amino]-6-bromoimidazo[1,5- a]pyrazine-1- carboxylate [0775] To NaH (4 g, 100 mmol, 1.2 equiv, 60% in oil) in DMF (400 mL) was added methyl 2-isocyanoacetate (9.9 g, 100 mmol, 1.2 equiv) dropwise at -30 °C and the reaction was stirred for 20 mins. A solution of tert-butyl N-(3-bromo-6-chloropyrazin-2-yl)-N-(tert- butoxycarbonyl)carbamate (34 g, 83.2 mmol, 1 equiv) in DMF (20 mL) was then added dropwise at -30 °C and the mixture stirred for 1 h at this temperature. The reaction was quenched with NH ₄ Cl (aq.) at 0 °C and extracted with EtOAc (3 x 500 mL). The combined organics were washed with water (3 x 600 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford methyl 5-[bis(tert-butoxycarbonyl)amino]-6-bromoimidazo[1,5- a]pyrazine-1-carboxylate (21 g, 54% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 471, 473 Synthesis of 160-c: methyl 5-amino-6-bromoimidazo[1,5-a]pyrazine-1-carboxylate [0776] To a stirred solution of methyl 5-[bis(tert-butoxycarbonyl)amino]-6- bromoimidazo[1,5-a]pyrazine-1-carboxylate (21 g, 44 mmol, 1 equiv) in DCM (100 mL) was added TFA (50 mL). The resulting mixture was stirred for 2 h at room temperature then concentrated. Diethyl ether was added and the precipitated solids were collected by filtration and washed with ethyl ether (2 x 100 mL). Drying gave methyl 5-amino-6- bromoimidazo[1,5-a]pyrazine-1-carboxylate (11 g, 91% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 271, 273 Synthesis of 160-d: methyl 6-bromo-5- chloroimidazo[1,5-a]pyrazine-1-carboxylate [0777] To a stirred solution of methyl 5-amino-6-bromoimidazo[1,5-a]pyrazine-1- carboxylate (3.3 g, 12 mmol, 1 equiv) in MeCN (40 mL) was added CuCl ₂ (4.9 g, 36 mmol, 3 equiv) and CuCl (2.4 g, 24 mmol, 2 equiv). To this mixture was added isopentyl nitrite (2.8 g, 24 mmol, 2 equiv) dropwise at room temperature. The resulting mixture was stirred for 3 h then quenched with water/ice (100 mL). This was extracted with EtOAc (3 x 100 mL), and the combined organics were washed with brine (100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (2:1) to afford methyl 6-bromo-5- chloroimidazo[1,5-a]pyrazine-1-carboxylate (1.2 g, 34% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 290, 292 Synthesis of 160-e: methyl 6-bromo-5-fluoroimidazo[1,5-a]pyrazine-1-carboxylate [0778] To a stirred solution of methyl 6-bromo-5-chloroimidazo[1,5-a]pyrazine-1- carboxylate (1.2 g, 4 mmol, 1 equiv) in DMF (40 mL) was added CsF (3.1 g, 20 mmol, 5 equiv). The reaction was stirred for 1 h at 100 °C, then cooled to 0 °C and quenched with 1 M HCl. The resulting mixture was diluted with water (200 mL) and extracted with EtOAc (3 x 200 mL). The combined organics were washed with water (3 x 200 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford methyl 6-bromo-5- fluoroimidazo[1,5-a]pyrazine-1-carboxylate (500 mg, 31% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 274, 276 Synthesis of 160-f: methyl 6-(3-amino-2,6-difluorophenyl)-5-fluoroimidazo[1,5-a]pyrazin e- 1-carboxylate [0779] To a stirred mixture of methyl 6-bromo-5-fluoroimidazo[1,5-a]pyrazine-1-carboxylate (500 mg, 1.8 mmol, 1 equiv) and 2,4-difluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)aniline (698 mg, 2.7 mmol, 1.5 equiv) in dioxane (15 mL) and H ₂ O (1.5 mL) was added Pd(dtbpf)Cl ₂ (119 mg, 0.18 mmol, 0.1 equiv) and K ₃ PO ₄ (774 mg, 3.6 mmol, 2 equiv) at room temperature under nitrogen atmosphere. The reaction was stirred for 1 h at 80 °C then cooled to 0 °C and quenched with water/ice (100 mL). The resulting mixture was extracted with EtOAc (3 x 100 mL) and the combined organics were washed with brine (100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (1:1) to afford methyl 6-(3-amino-2,6- difluorophenyl)-5-fluoroimidazo[1,5-a]pyrazine-1-carboxylate (410 mg, 69% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 323 Synthesis of 160-g: 6-(3-amino-2,6-difluorophenyl)-5-fluoroimidazo[1,5-a]pyrazin e-1- carboxylic acid [0780] To a stirred mixture of methyl 6-(3-amino-2,6-difluorophenyl)-5-fluoroimidazo[1,5- a]pyrazine-1-carboxylate (420 mg, 1.3 mmol, 1 equiv) in DCM (10 mL) was added BBr ₃ (2 mL) at room temperature. The resulting mixture was stirred for 3 h then concentrated. This resulted in 6-(3-amino-2,6-difluorophenyl)-5-fluoroimidazo[1,5-a]pyrazin e-1-carboxylic acid (500 mg, 87% yield) as a brown solid. The crude product was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 309 Synthesis of 160-h: 6-(3-amino-2,6- difluorophenyl)-5-fluoro-N-methylimidazo[1,5- a]pyrazine-1- carboxamide [0781] To a stirred mixture of 6-(3-amino-2,6-difluorophenyl)-5-fluoroimidazo[1,5- a]pyrazine-1-carboxylic acid (500 mg, 1.6 mmol, 1 equiv) in DMF (8 mL) was added HATU (925 mg, 2.4 mmol, 1.5 equiv), DIEA (629 mg, 4.9 mmol, 3 equiv) and methylamine hydrochloride (219 mg, 3.2 mmol, 2 equiv). The reaction was stirred for 1 h, then quenched by the addition of MeOH (3 mL). Concentration gave a residue which was purified by Flash- Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820- 40 μm, 120 g; mobile phase: 5-50% MeCN / 0.1% aqueous TFA; to give 6-(3-amino-2,6- difluorophenyl)-5-fluoro-N-methylimidazo[1,5-a]pyrazine-1-ca rboxamide (250 mg, 48% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 322 Synthesis of Compound 160: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-fluoro-N-methylimidazo[1,5-a]pyrazine-1-ca rboxamide [0782] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-5-fluoro-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (80 mg, 0.25 mmol, 1 equiv) in pyridine (3 mL) was added 5-chloro-2-methoxypyridine-3-sulfonyl chloride (120 mg, 0.5 mmol, 2 equiv) in portions at room temperature. The resulting mixture was stirred overnight then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 20-55% MeCN / 0.1% aqueous formic acid; to give 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-5-fluoro-N-methylimidazo[1,5-a]pyrazine-1-ca rboxamide (50 mg, 38% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 527 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.50 (s, 1H), 9.36 (d, J = 2.9 Hz, 1H), 8.92 (s, 1H), 8.53 (dd, J = 11.6, 3.7 Hz, 2H), 8.09 (d, J = 2.6 Hz, 1H), 7.52 (td, J = 8.9, 5.8 Hz, 1H), 7.31 (td, J = 9.0, 1.6 Hz, 1H), 3.91 (s, 3H), 2.85 (d, J = 4.7 Hz, 3H). Example 176: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(2-hydroxyethyl)imidazo[1,5-a]pyrazine-1-c arboxamide (Compound 161) Synthesis of Compound 161: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(2-hydroxyethyl)imidazo[1,5-a]pyrazine-1-c arboxamide [0783] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added ethanolamine (36 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv) at room temperature. The reaction was stirred for 1 h, then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL), and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 10-30% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-(2-hydr oxyethyl)imidazo[1,5- a]pyrazine-1-carboxamide (103 mg, 47% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 539 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.72-8.60 (m, 2H), 8.51 (d, J = 2.6 Hz, 1H), 8.29 (t, J = 5.8 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.25 (td, J = 9.0, 1.6 Hz, 1H), 4.80 (s, 1H), 3.92 (s, 3H), 3.56 (t, J = 6.2 Hz, 2H), 3.41 (q, J = 6.1 Hz, 2H). Example 177: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(1-methylpyrazol-4-yl)imidazo[1,5-a]pyrazi ne-1-carboxamide (Compound 162) Synthesis of Compound 162: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(1-methylpyrazol-4-yl)imidazo[1,5-a]pyrazi ne-1-carboxamide [0784] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added 1-methylpyrazol-4-amine (58 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1h then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL) and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 5-55% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-(1-methylpyrazol-4-yl)imi dazo[1,5-a]pyrazine-1- carboxamide (92 mg, 40% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 575 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.65 (s, 1H), 10.46 (s, 1H), 9.58 (d, J = 1.6 Hz, 1H), 8.73 (d, J = 6.6 Hz, 2H), 8.51 (d, J = 2.6 Hz, 1H), 8.17-7.97 (m, 2H), 7.72 (s, 1H), 7.43 (td, J = 8.8, 5.8 Hz, 1H), 7.26 (td, J = 9.1, 1.5 Hz, 1H), 3.93 (s, 3H), 3.83 (s, 3H). Example 178: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(oxan-4-ylmethyl)imidazo[1,5-a]pyrazine-1- carboxamide (Compound 163) Synthesis of Compound 163: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(oxan-4-ylmethyl)imidazo[1,5-a]pyrazine-1- carboxamide [0785] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added 1-(oxan-4-yl)methanamine (69 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1h, then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL), and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50 x 250 mm, 10 μm; Mobile Phase: 25-60% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-(oxan-4-ylmethyl)imidazo[ 1,5-a]pyrazine-1- carboxamide (88 mg, 37% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 593 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.44 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.76-8.61 (m, 2H), 8.55-8.31 (m, 2H), 8.09 (d, J = 2.6 Hz, 1H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.25 (td, J = 9.0, 1.6 Hz, 1H), 3.92 (s, 3H), 3.89-3.80 (m, 1H), 3.30 - 3.18 (m, 4H), 1.86 (ddd, J = 11.3, 7.5, 4.1 Hz, 1H), 1.59 (dd, J = 12.9, 3.7 Hz, 2H), 1.32 -1.09 (m, 2H). Example 179: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(2-methanesulfonylethyl)imidazo[1,5-a]pyra zine-1-carboxamide (Compound 164) Synthesis of Compound 164: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(2-methanesulfonylethyl)imidazo[1,5-a]pyra zine-1-carboxamide [0786] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added 2-methanesulfonylethanamine (74 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The resulting mixture was stirred for 1 h, then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL) and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 15-55% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-(2- methanesulfonylethyl)imidazo[1,5-a]pyrazine-1-carboxamide (85 mg, 35% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 601 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.47 (s, 1H), 9.52 (d, J = 1.6 Hz, 1H), 8.81-8.56 (m, 3H), 8.44 (d, J = 2.6 Hz, 1H), 8.07 (d, J = 2.6 Hz, 1H), 7.38 (td, J = 9.0, 5.9 Hz, 1H), 7.17 (t, J = 9.1 Hz, 1H), 3.90 (s, 3H), 3.77 (q, J = 6.6 Hz, 2H), 3.43 (t, J = 6.9 Hz, 2H), 3.06 (s, 3H). Example 180: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-ethylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 165) Synthesis of Compound 165: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-ethylimidazo[1,5-a]pyrazine-1-carboxamide [0787] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added ethylamine hydrochloride (49 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1 h, then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL) and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 30-60% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-ethylimidazo[1,5-a]pyrazi ne-1-carboxamide (87 mg, 41% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 523 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.67 (d, J = 5.5 Hz, 2H), 8.55-8.39 (m, 2H), 8.09 (d, J = 2.6 Hz, 1H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.25 (td, J = 9.0, 1.6 Hz, 1H), 3.92 (s, 3H), 3.37-3.31 (m, 2H), 1.15 (t, J = 7.1 Hz, 3H).

Example 181: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(cyclopropylmethyl)imidazo[1,5-a]pyrazine- 1-carboxamide (Compound 166) Synthesis of Compound 166: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(cyclopropylmethyl)imidazo[1,5-a]pyrazine- 1-carboxamide [0788] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added 1-cyclopropylmethylamine (43 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1 h, then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL), and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 35-75% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-(cyclopropylmethyl)imidaz o[1,5-a]pyrazine-1- carboxamide (75 mg, 34% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 549 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 9.52 (d, J = 1.6 Hz, 1H), 8.68 (d, J = 3.4 Hz, 2H), 8.55-8.29 (m, 2H), 8.09 (d, J = 2.6 Hz, 1H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.26 (td, J = 8.7, 1.4 Hz, 1H), 3.92 (s, 3H), 3.24-3.06 (m, 2H), 1.09 (ddd, J = 12.6, 7.8, 5.1 Hz, 1H), 0.55- 0.35 (m, 2H), 0.35-0.19 (m, 2H). Example 182: Synthesis of 6-[3-(5-chloro-2-ethoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 167) Synthesis of 167-a: 3-bromo-5-chloro-2-ethoxypyridine [0789] A solution of 3-bromo-5-chloro-2-fluoropyridine (1 g, 4.8 mmol, 1 equiv) and sodium ethoxide (0.97 g, 14 mmol, 3 equiv) in EtOH (10 mL) was stirred for 2 h at 80 °C. The mixture was cooled and quenched with H ₂ O (100 mL), then extracted with EA (3 x 50 mL). The combined organics were washed with brine (100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 40-90% MeCN / 0.1% aqueous formic acid; to afford 3-bromo-5-chloro-2-ethoxypyridine (0.7 g, 62% yield) as a light yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 236, 238 Synthesis of 167-b: 3-(benzylsulfanyl)-5-chloro-2-ethoxypyridine [0790] To a stirred solution of 3-bromo-5-chloro-2-ethoxypyridine (645 mg, 2.7 mmol, 1 equiv), DIEA (1058 mg, 8.2 mmol, 3 equiv) and benzyl mercaptan (508 mg, 4.1 mmol, 1.5 equiv) in toluene (10 mL) were added XantPhos (316 mg, 0.54 mmol, 0.2 equiv) and Pd ₂ (dba) ₃ CHCl ₃ (282 mg, 0.27 mmol, 0.1 equiv) in portions under nitrogen atmosphere. The resulting mixture was stirred for 5 h at 115 °C, then cooled, quenched with H ₂ O (20 mL) and extracted with EA (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep- HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 50-90% MeCN / 0.1% aqueous formic acid; to afford 3- (benzylsulfanyl)-5-chloro-2-ethoxypyridine (470 mg, 62% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 280 Synthesis of 167-c: 5-chloro-2-ethoxypyridine-3-sulfonyl chloride [0791] To a stirred solution of 3-(benzylsulfanyl)-5-chloro-2-ethoxypyridine (476 mg, 1.7 mmol, 1 equiv) in HOAc (6 mL) and H ₂ O (2 mL) was added NCS (795 mg, 5.95 mmol, 3.5 equiv) in portions at 0 °C. The reaction was stirred for 0.5 h at room temperature, then quenched with H ₂ O (10 mL) and extracted with EA (3 x 5 mL). The combined organics were washed with NaHCO ₃ (10 mL) and brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated to give crude 5-chloro-2-ethoxypyridine-3-sulfonyl chloride (640 mg) as a yellow oil, which was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 256 Synthesis of Compound 167: 6-[3-(5-chloro-2-ethoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide [0792] To a stirred solution of 5-chloro-2-ethoxypyridine-3-sulfonyl chloride (200 mg, 0.78 mmol, 1 equiv) in pyridine (2 mL) was added 6-(3-amino-2,6-difluorophenyl)-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (474 mg, 1.56 mmol, 2 equiv) in DCM (0.5 mL) dropwise at room temperature. The resulting mixture was stirred for 1 h then quenched with H ₂ O (10 mL) and extracted with EA (3 x 5 mL). The combined organics were washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 35-70% MeCN / 0.1% aqueous formic acid; to afford 6-[3-(5-chloro- 2-ethoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-methyl imidazo[1,5-a]pyrazine-1- carboxamide (150 mg, 37% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 523 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.34 (s, 1H), 9.51 (d, J = 1.7 Hz, 1H), 8.65 (d, J = 1.9 Hz, 2H), 8.44 (dd, J = 18.6, 3.6 Hz, 2H), 8.09 (d, J = 2.6 Hz, 1H), 7.43 (td, J = 9.0, 5.9 Hz, 1H), 7.24 (td, J = 9.2, 1.7 Hz, 1H), 4.39 (q, J = 7.0 Hz, 2H), 2.84 (d, J = 4.8 Hz, 3H), 1.22 (t, J = 7.0 Hz, 3H). Example 183: Synthesis of 6-[3-(5-chloro-2-isopropoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 168) Synthesis of 168-a: 3-bromo-5-chloro-2-isopropoxypyridine [0793] A solution of 3-bromo-5-chloro-2-fluoropyridine (1 g, 4.8 mmol, 1 equiv), i-PrOH (0.86 g, 14 mmol, 3 equiv) and Cs ₂ CO ₃ (4.65 g, 14 mmol, 3 equiv) in DMSO (10 mL) was stirred for 2 h at 80 °C. The resulting mixture was quenched with H ₂ O (20 mL) and extracted with EA (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 50-90% MeCN / 0.1% aqueous formic acid; to afford 3-bromo-5-chloro-2- isopropoxypyridine (800 mg, 67% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 250, 252 Synthesis of 168-b: 3-(benzylsulfanyl)-5-chloro-2-isopropoxypyridine [0794] To a stirred solution of 3-bromo-5-chloro-2-isopropoxypyridine (775 mg, 3.1 mmol, 1 equiv), DIEA (800 mg, 6.2 mmol, 2 equiv) and benzyl mercaptan (576 mg, 4.6 mmol, 1.5 equiv) in toluene (10 mL) were added XantPhos (358 mg, 0.62 mmol, 0.2 equiv) and Pd ₂ (dba) ₃ CHCl ₃ (320 mg, 0.31 mmol, 0.1 equiv) in portions at room temperature under nitrogen atmosphere. The reaction was stirred for 2 h at 80 °C then quenched with H ₂ O (20 mL) and extracted with EA (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash- Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820- 40 μm, 120 g; mobile phase: 50-95% MeCN / 0.1% aqueous formic acid; to afford 3- (benzylsulfanyl)-5-chloro-2-isopropoxypyridine (570 mg, 63% yield) as a light yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 294 Synthesis of 168-c: 5-chloro-2-isopropoxypyridine-3-sulfonyl chloride [0795] To a stirred solution of 3-(benzylsulfanyl)-5-chloro-2-isopropoxypyridine (570 mg, 1.9 mmol, 1 equiv) in HOAc (6 mL) and H ₂ O (2 mL) was added NCS (907 mg, 6.8 mmol, 3.5 equiv) in portions at 0 °C. The reaction was stirred for 0.5 h at room temperature, then quenched with H ₂ O (20 mL) and extracted with EA (3 x 10 mL). The combined organics were washed with NaHCO ₃ (20 mL) and brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated to give crude 5-chloro-2-isopropoxypyridine-3-sulfonyl chloride (730 mg) as a yellow oil which was used in next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 270 Synthesis of Compound 168: 6-[3-(5-chloro-2-isopropoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide [0796] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (197 mg, 0.65 mmol, 0.5 equiv) in pyridine (4 mL) was added 5- chloro-2-isopropoxypyridine-3-sulfonyl chloride (350 mg, 1.3 mmol, 1 equiv) in DCM (0.5 mL) dropwise. The resulting mixture was stirred for 0.5 h then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 35-70% MeCN / 0.1% aqueous formic acid; to afford 6- [3-(5-chloro-2-isopropoxypyridine-3-sulfonamido)-2,6-difluor ophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (150 mg, 22% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 537 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.24 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.66 (d, J = 1.5 Hz, 2H), 8.47 (d, J = 2.6 Hz, 1H), 8.41 (q, J = 4.5 Hz, 1H), 8.10 (d, J = 2.6 Hz, 1H), 7.45 (td, J = 8.9, 5.9 Hz, 1H), 7.26 (td, J = 9.1, 1.7 Hz, 1H), 5.31 (h, J = 6.0 Hz, 1H), 2.84 (d, J = 4.7 Hz, 3H), 1.21 (d, J = 6.1 Hz, 6H). Example 184: Synthesis of 6-[3-(5-chloro-2-cyclopropoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 169) p Synthesis of 169-a 3-bromo-5-chloro-2-cyclopropoxypyridine [0797] A solution of 3-bromo-5-chloro-2-fluoropyridine (1 g, 4.8 mmol, 1 equiv), caesium carbonate (4.7 g, 14 mmol, 3 equiv) and cyclopropanol (0.83 g, 14 mmol, 3 equiv) in DMSO (10 mL) was stirred for 2 h at 80 °C. The resulting mixture was quenched with H ₂ O (20 mL) and extracted with EA (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep- HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 40-90% MeCN / 0.1% aqueous formic acid; to afford 3-bromo-5- chloro-2-cyclopropoxypyridine (800 mg, 68% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 248, 250 Synthesis of 169-b: 3-(benzylsulfanyl)-5-chloro-2-cyclopropoxypyridine [0798] To a stirred solution of 3-bromo-5-chloro-2-cyclopropoxypyridine (775 mg, 3.1 mmol, 1 equiv), DIEA (806 mg, 6.2 mmol, 2 equiv) and benzyl mercaptan (581 mg, 4.7 mmol, 1.5 equiv) in toluene (10 mL) were added XantPhos (361 mg, 0.62 mmol, 0.2 equiv) and Pd ₂ (dba) ₃ CHCl ₃ (323 mg, 0.31 mmol, 0.1 equiv) in portions at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 2 h at 115 °C then cooled and quenched with H ₂ O (30 mL) and extracted with EA (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 50-80% MeCN / 0.1% aqueous formic acid; to afford 3-(benzylsulfanyl)-5-chloro-2-cyclopropoxypyridine (565 mg, 62% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 292 Synthesis of 169-c: 5-chloro-2-cyclopropoxypyridine-3-sulfonyl chloride [0799] To a stirred solution of 3-(benzylsulfanyl)-5-chloro-2-cyclopropoxypyridine (560 mg, 1.9 mmol, 1 equiv) in HOAc (6 mL) and H ₂ O (2 mL) was added NCS (897 mg, 6.7 mmol, 3.5 equiv) in portions at 0°C. The resulting mixture was stirred for 30 min at room temperature, then quenched with H ₂ O (20 mL) and extracted with EA (3 x 10 mL). The combined organics were washed with NaHCO ₃ (30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated to afford 5-chloro-2-cyclopropoxypyridine-3-sulfonyl chloride (717 mg) as a yellow oil. The crude product mixture was used in the next step directly without further purification. LCMS (ES, m/z): [M+H] ⁺ : 268 Synthesis of Compound 169: 6-[3-(5-chloro-2-cyclopropoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide [0800] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (167 mg, 0.56 mmol, 0.5 equiv) in pyridine (10 mL) was added 5- chloro-2-cyclopropoxypyridine-3-sulfonyl chloride (300 mg, 1.1 mmol, 1 equiv) in DCM (0.5 mL) dropwise. The resulting mixture was stirred for 1h then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 30-70% MeCN / 0.1% aqueous formic acid; to afford 6- [3-(5-chloro-2-cyclopropoxypyridine-3-sulfonamido)-2,6-diflu orophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (110 mg, 18% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 535 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.33 (s, 1H), 9.51 (d, J = 1.7 Hz, 1H), 8.65 (d, J = 2.9 Hz, 2H), 8.53 (d, J = 2.5 Hz, 1H), 8.41 (d, J = 4.9 Hz, 1H), 8.10 (d, J = 2.6 Hz, 1H), 7.42 (td, J = 8.9, 5.8 Hz, 1H), 7.33-7.19 (m, 1H), 4.32 (tt, J = 6.2, 3.1 Hz, 1H), 2.84 (d, J = 4.8 Hz, 3H), 0.81-0.52 (m, 4H). Example 185: Synthesis of 6-[2,6-difluoro-3-(5-fluoro-2-methoxypyridine-3- sulfonamido)phenyl]-5-fluoro-N-methylimidazo[1,5-a]pyrazine- 1-carboxamide (Compound 170) [0801] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-5-fluoro-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (60 mg, 0.2 mmol, 1 equiv) in pyridine (3 mL) was added 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (84 mg, 0.4 mmol, 2 equiv). The reaction was stirred overnight then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 μm; Mobile Phase: 17-55% MeCN / 0.1% aqueous formic acid; to give 6-[2,6-difluoro-3-(5-fluoro-2- methoxypyridine-3-sulfonamido)phenyl]-5-fluoro-N-methylimida zo[1,5-a]pyrazine-1- carboxamide (20 mg, 21% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 511 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.48 (s, 1H), 9.36 (d, J = 2.8 Hz, 1H), 8.92 (s, 1H), 8.55 (d, J = 4.9 Hz, 1H), 8.46 (d, J = 3.0 Hz, 1H), 8.02 (dd, J = 7.3, 3.0 Hz, 1H), 7.51 (td, J = 8.9, 5.8 Hz, 1H), 7.29 (dd, J = 9.8, 8.3 Hz, 1H), 3.89 (s, 3H), 2.85 (d, J = 4.7 Hz, 3H). Example 186: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxamide (Compound 171) Synthesis of Compound 171: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxamide [0802] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added NH ₄ Cl (32 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1 then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL), and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ , then concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: XBridge Shield RP18 OBD, 5 µm,19*150 mm; Mobile Phase: 4-27% MeCN / 0.05% aqueous ammonia; to afford 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxamide (60 mg, 30% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 495 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.44 (s, 1H), 9.50 (d, J = 1.6 Hz, 1H), 8.71-8.62 (m, 2H), 8.51 (d, J = 2.6 Hz, 1H), 8.09 (d, J = 2.6 Hz, 1H), 7.79 (s, 1H), 7.51 (s, 1H), 7.42 (td, J = 8.8, 5.8 Hz, 1H), 7.25 (td, J = 9.1, 1.6 Hz, 1H), 3.92 (s, 3H). Example 187: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[3-(dimethylamino)propyl]imidazo[1,5-a]pyr azine-1-carboxamide (Compound 172) Synthesis of Compound 172: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[3-(dimethylamino)propyl]imidazo[1,5-a]pyr azine-1-carboxamide [0803] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added dimethylaminopropylamine (61 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1 h, then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL), and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na2SO4, then concentrated. The crude product was purified by Prep-HPLC with following conditions: Column, XBridge Prep C18 OBD, 5 µm, 19*150 mm, Mobile Phase: 12-34% MeCN / 0.5% aqueous ammonia; to afford 6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-[3-(dimethylamino)propyl] imidazo[1,5-a]pyrazine-1- carboxamide (46 mg, 20% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 580 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 9.52 (d, J = 1.6 Hz, 1H), 8.65 (d, J = 2.5 Hz, 2H), 8.60 (t, J = 6.0 Hz, 1H), 8.35 (d, J = 2.7 Hz, 1H), 8.04 (d, J = 2.7 Hz, 1H), 7.32 (td, J = 9.1, 6.0 Hz, 1H), 7.05 (t, J = 9.3 Hz, 1H), 3.86 (s, 3H), 3.37 (d, J = 6.5 Hz, 2H), 2.67 (t, J = 7.2 Hz, 2H), 2.45 (s, 6H), 1.80 (m, 2H). Example 188: Synthesis of (R)-6-(3-((5-chloro-2-methoxypyridine)-3-sulfonamido)-2,6- difluorophenyl)-N-(1-methylpyrrolidin-3-yl)imidazo[1,5-a]pyr azine-1-carboxamide & and (S)-6-(3-((5-chloro-2-methoxypyridine)-3-sulfonamido)-2,6-di fluorophenyl)-N-(1- methylpyrrolidin-3-yl)imidazo[1,5-a]pyrazine-1-carboxamide (Compounds 173-1 & 173-2) Synthesis of Compounds 173-1 & 173-2: (R)-6-(3-((5-chloro-2-methoxypyridine)-3- sulfonamido)-2,6-difluorophenyl)-N-(1-methylpyrrolidin-3-yl) imidazo[1,5-a]pyrazine-1- carboxamide and (S)-6-(3-((5-chloro-2-methoxypyridine)-3-sulfonamido)-2,6- difluorophenyl)-N-(1-methylpyrrolidin-3-yl)imidazo[1,5-a]pyr azine-1-carboxamide [0804] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added 1-methylpyrrolidin-3-amine (61 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv. The reaction was stirred for 1 h at room temperature, then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL), and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 5-30% MeCN / 0.1% aqueous formic acid; to afford racemic 6-(3-((5- chloro-2-methoxypyridine)-3-sulfonamido)-2,6-difluorophenyl) -N-(1-methylpyrrolidin-3- yl)imidazo[1,5-a]pyrazine-1-carboxamide (150 mg, 64% yield) as a white solid. [0805] This was separated by SFC with the following conditions Column: Lux 5 µm Cellulose-2, 3*25 cm, 5 µm; Mobile Phase: 55% 1:1 MeOH:MeCN / CO ₂ ; Flow rate: 100 mL/min; Temperature: 35 °C; to give (R)-6-(3-((5-chloro-2-methoxypyridine)-3- sulfonamido)-2,6-difluorophenyl)-N-(1-methylpyrrolidin-3-yl) imidazo[1,5-a]pyrazine-1- carboxamide (retention time 9.65 mins, 60 mg, stereochemistry randomly assigned) and (S)- 6-(3-((5-chloro-2-methoxypyridine)-3-sulfonamido)-2,6-difluo rophenyl)-N-(1- methylpyrrolidin-3-yl)imidazo[1,5-a]pyrazine-1-carboxamide (retention time 15.59 mins, 65 mg, stereochemistry assigned as opposite to other enantiomer) as white solids. LCMS (ES, m/z): [M+H] ⁺ : 578 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 9.49 (d, J = 1.6 Hz, 1H), 8.64 (d, J = 7.2 Hz, 2H), 8.30 (d, J = 2.6 Hz, 1H), 8.01 (d, J = 2.6 Hz, 1H), 7.29 (td, J = 9.0, 5.9 Hz, 1H), 7.02 (t, J = 9.2 Hz, 1H), 4.59 (t, J = 8.0 Hz, 1H), 3.83 (s, 3H), 3.12 (q, J = 9.9, 9.5 Hz, 2H), 2.97- 2.79 (m, 2H), 2.56 (s, 3H), 2.31 (dd, J = 13.9, 6.0 Hz, 1H), 1.94 (q, J = 6.5 Hz, 1H). LCMS (ES, m/z): [M+H] ⁺ : 578 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 9.49 (d, J = 1.7 Hz, 1H), 8.64 (d, J = 6.6 Hz, 2H), 8.30 (d, J = 2.6 Hz, 1H), 8.01 (d, J = 2.6 Hz, 1H), 7.32 – 7.16 (m, 1H), 7.02 (t, J = 8.9 Hz, 1H), 4.56 (d, J = 14.5 Hz, 1H), 3.83 (s, 3H), 3.20 – 3.00 (m, 2H), 2.97 – 2.72 (m, 2H), 2.55 (s, 3H), 2.30 (td, J = 14.2, 8.5 Hz, 1H), 1.95 (dt, J = 12.4, 6.3 Hz, 1H). Example 189: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(1,2-oxazol-4-yl)imidazo[1,5-a]pyrazine-1- carboxamide (Compound 174) Synthesis of Compound 174: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-(1,2-oxazol-4-yl)imidazo[1,5-a]pyrazine-1- carboxamide [0806] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added 1,2-oxazol-4-amine (50 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1 h at room temperature, then diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL), and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: XBridge Shield RP18 OBD, 5 µm, 19*150 mm; Mobile Phase: 14-27% MeCN / 0.05% aqueous ammonia; to afford 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-(1,2-ox azol-4-yl)imidazo[1,5- a]pyrazine-1-carboxamide (73 mg, 32% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 562 Example 190: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[2-(morpholin-4-yl)ethyl]imidazo[1,5-a]pyr azine-1-carboxamide (Compound 175) Synthesis of Compound 175: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[2-(morpholin-4-yl)ethyl]imidazo[1,5-a]pyr azine-1-carboxamide [0807] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added N-aminoethylmorpholine (78 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1 h at room temperature, then was diluted with H ₂ O (50 mL). The resulting mixture was extracted with EA (3 x 50 mL) and the combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: Sunfire Prep C18 OBD, 50*250 mm 5µm 10nm; Mobile Phase: 5-40% MeCN / 0.05% aqueous ammonia; to afford 6-[3-(5-chloro-2- methoxypyridine-3-sulfonamido)-2,6-difluorophenyl]-N-[2-(mor pholin-4- yl)ethyl]imidazo[1,5-a]pyrazine-1-carboxamide (54 mg, 22% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 608 1H NMR (300 MHz, DMSO-d ₆ ) δ 10.42 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.67 (d, J = 3.8 Hz, 2H), 8.48 (d, J = 2.6 Hz, 1H), 8.31 (t, J = 5.9 Hz, 1H), 8.08 (d, J = 2.6 Hz, 1H), 7.40 (td, J = 8.9, 5.8 Hz, 1H), 7.22 (td, J = 9.1, 1.6 Hz, 1H), 3.91 (s, 3H), 3.59 (t, J = 4.6 Hz, 4H), 3.46 (q, J = 6.4 Hz, 2H), 2.54 (d, J = 7.0 Hz, 2H), 2.46 (t, J = 4.7 Hz, 4H). Example 191: Synthesis of 6-[3-[5-chloro-2-(2-methylpropoxy)pyridine-3-sulfonamido]- 2,6-difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxa mide (Compound 176) Synthesis of 176-a: 3-bromo-5-chloro-2-(2-methylpropoxy)pyridine [0808] To a stirred solution of 3-bromo-5-chloro-2-fluoropyridine (1 g, 4.8 mmol, 1 equiv) and cesium carbonate (4.7 g, 14 mmol, 3 equiv) in DMSO (10 mL) was added isobutanol (1.06 g, 14 mmol, 3 equiv). The resulting mixture was stirred for 2 h at 80 °C, then cooled and quenched with H ₂ O (20 mL). The mixture was extracted with EtOAc (3 x 10 mL), and the combined organics washed with brine (10 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 50-90% MeCN / 0.1% aqueous formic acid; to afford 3-bromo-5-chloro-2-(2-methylpropoxy)pyridine (1.07 g, 85% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 264, 266 Synthesis of 176-b: 3-(benzylsulfanyl)-5-chloro-2-(2-methylpropoxy)pyridine [0809] To a stirred solution of 3-bromo-5-chloro-2-(2-methylpropoxy)pyridine (1.08 g, 4.1 mmol, 1 equiv), DIEA (1.06 g, 8.2 mmol, 2 equiv) and benzyl mercaptan (0.76 g, 6.1 mmol, 1.5 equiv) in toluene (15 mL) were added XantPhos (0.47 g, 0.82 mmol, 0.2 equiv) and Pd ₂ (dba) ₃ .CHCl ₃ (0.42 g, 0.41 mmol, 0.1 equiv) in portions at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 5 h at 115 °C then cooled and quenched with H ₂ O (20 mL). The mixture was extracted with EtOAc (3 x 10 mL), and the combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 40-90% MeCN / 0.1% aqueous formic acid; to afford 3-(benzylsulfanyl)-5-chloro-2-(2- methylpropoxy)pyridine (1.16 g, 92% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 308 Synthesis of 176-c: 5-chloro-2-(2-methylpropoxy)pyridine-3-sulfonyl chloride [0810] To a stirred solution of 3-(benzylsulfanyl)-5-chloro-2-(2-methylpropoxy)pyridine (710 mg, 2.3 mmol, 1 equiv) in HOAc (9 mL) and H ₂ O (3 mL) was added NCS (1080 mg, 8.1 mmol, 3.5 equiv) in portions at 0 °C. The resulting mixture was stirred for 1 h at room temperature, then concentrated to afford crude 5-chloro-2-(2-methylpropoxy)pyridine-3- sulfonyl chloride (620 mg, 95% yield) as a white oil which was used in next step directly without further purification. Synthesis of Compound 176: 6-[3-[5-chloro-2-(2-methylpropoxy)pyridine-3-sulfonamido]- 2,6-difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxa mide [0811] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (192 mg, 0.63 mmol, 0.3 equiv) in pyridine (5 mL) was added 5- chloro-2-(2-methylpropoxy)pyridine-3-sulfonyl chloride (600 mg, 2.1 mmol, 1 equiv) in DCM (0.5 mL). The resulting mixture was stirred for 2 h at room temperature, then quenched with H ₂ O (25 mL) and extracted with EtOAc (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 20-65% MeCN / 0.1% aqueous formic acid; to afford 6- [3-[5-chloro-2-(2-methylpropoxy)pyridine-3-sulfonamido]-2,6- difluorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (120 mg, 10% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 551 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.29 (s, 1H), 9.51 (d, J = 1.7 Hz, 1H), 8.66 (d, J = 5.4 Hz, 2H), 8.45 (dd, J = 15.0, 3.9 Hz, 2H), 8.12 (d, J = 2.6 Hz, 1H), 7.51-7.37 (m, 1H), 7.32-7.20 (m, 1H), 4.11 (d, J = 6.9 Hz, 2H), 2.88-2.80 (m, 3H), 1.89 (dt, J = 13.7, 6.6 Hz, 1H), 0.87 (d, J = 6.7 Hz, 6H). Example 192: Synthesis of N-[3-[1-(5-cyclopropyl-3H-imidazol-4-yl)imidazo[1,5- a]pyrazin-6-yl]-2,4-difluorophenyl]-5-fluoro-2-methoxypyridi ne-3-sulfonamide (Compound 177) Synthesis of 177-a: 4,5-diiodo-1H-imidazole [0812] A mixture of KI (29.3 g, 176 mmol, 4 equiv) and I ₂ (22.4 g, 88 mmol, 2 equiv) in water (60 mL) was added to a solution of imidazole (3 g, 44 mmol, 1 equiv) in 2 M aqueous NaOH (133 mL, 266 mmol, 6 equiv). The mixture was stirred for 3 h and then neutralized with 6 M HCl. The resulting solid was collected by filtration and recrystallized from ethanol (100 mL) to give 4,5-diiodo-1H-imidazole (14 g, 99% yield) as a grey solid. LCMS (ES, m/z): [M+H] ⁺ : 321 Synthesis of 177-b: 4,5-diiodo-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole [0813] To 4,5-diiodo-1H-imidazole (6 g, 18.8 mmol, 1 equiv) in THF (60 mL) was added NaH (1.3 g, 20.1 mmol, 1.1 equiv) at 0 °C. The mixture was stirred for 30 min, then SEM-Cl (4.07 g, 24.4 mmol, 1.3 equiv) was added dropwise. The reaction was stirred for 3 h at 0 °C, then quenched by the addition of ice/water (150 mL). The resulting solution was extracted with ethyl acetate (3 x 100 mL), and the combined organics were washed with water (200 mL) and brine (200 mL), before being dried over anhydrous sodium sulfate and concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (1:3), to give 4,5-diiodo-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole (6 g, 71% yield) as a light yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 451 Synthesis of 177-c: 4-cyclopropyl-5-iodo-1-[[2-(trimethylsilyl)ethoxy]methyl]imi dazole [0814] 4,5-Diiodo-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole (2.5 g, 5.6 mmol, 1 equiv), cyclopropylboronic acid (1.43 g, 17 mmol, 3 equiv), Pd(PPh ₃ ) ₄ (1.28 g, 1.1 mmol, 0.2 equiv) and K ₂ CO ₃ (1.92 g, 14 mmol, 2.5 equiv) in toluene (50 mL) and H ₂ O (3 mL) were stirred for 1 day at 120 °C. The resulting mixture was concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 20-85% MeCN / 0.1% aqueous formic acid; to give 4-cyclopropyl-5-iodo-1-[[2-(trimethylsilyl)ethoxy]methyl]imi dazole (0.26 g, 13% yield) as a light brown semi-solid. LCMS (ES, m/z): [M+H] ⁺ : 365 Synthesis of 177-d: 4-cyclopropyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl )-1-((2- (trimethylsilyl)ethoxy)methyl)-1H-imidazole [0815] 4-Cyclopropyl-5-iodo-1-[[2-(trimethylsilyl)ethoxy]methyl]imi dazole (260 mg, 0.71 mmol, 1 equiv), bis(pinacolato)diboron (363 mg, 1.4 mmol, 2 equiv), Pd ₂ (dba) ₃ (130 mg, 0.14 mmol, 0.2 equiv), PCy ₃ (60 mg, 0.21 mmol, 0.3 equiv) and K ₂ CO ₃ (197 mg, 1.4 mmol, 2 equiv) in dioxane (10 mL) were stirred for 5 h at 100 °C. The reaction mixture was used in the next step directly. LCMS (ES, m/z): [M+H] ⁺ : 365 Synthesis of 177-e: 3-[1-(5-cyclopropyl-3-[[2-(trimethylsilyl)ethoxy]methyl]imid azol-4- yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluoroaniline: [0816] To the crude solution of 4-cyclopropyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole from the previous step was added 2,4- difluoro-3-[1-iodoimidazo[1,5-a]pyrazin-6-yl]aniline (153 mg, 0.41 mmol, 1.5 equiv), K ₂ CO ₃ (76 mg, 0.55 mmol, 2 equiv), H ₂ O (0.5 mL) and Pd(dppf)Cl ₂ CH ₂ Cl ₂ (45 mg, 0.055 mmol, 0.2 equiv). The resulting solution was stirred overnight at 100 °C, then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 10-85% MeCN / 0.1% aqueous ammonia; to give 3-[1-(5-cyclopropyl-3-[[2-(trimethylsilyl)ethoxy]methyl]imid azol- 4-yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluoroaniline (100 mg 76% yield) as a light brown solid. LCMS (ES, m/z): [M+H] ⁺ : 483 Synthesis of 177-f: N-[3-[1-(5-cyclopropyl-3-[[2-(trimethylsilyl)ethoxy]methyl]i midazol-4- yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluorophenyl]-5-fluoro- 2-methoxypyridine-3- sulfonamide [0817] Into a 40 mL vial was placed 3-[1-(5-cyclopropyl-3-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-4-yl)imidazo[1,5-a]py razin-6-yl]-2,4-difluoroaniline (130 mg, 0.27 mmol, 1 equiv), pyridine (5 mL) and 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (122 mg, 0.54 mmol, 2 equiv). The resulting solution was stirred overnight, then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 10- 80% MeCN / 0.1% aqueous TFA; to give N-[3-[1-(5-cyclopropyl-3-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-4-yl)imidazo[1,5-a]py razin-6-yl]-2,4- difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (130 mg 72% yield) as a light brown semi-solid. LCMS (ES, m/z): [M+H] ⁺ : 672 Synthesis of Compound 177: N-[3-[1-(5-cyclopropyl-3H-imidazol-4-yl)imidazo[1,5- a]pyrazin-6-yl]-2,4-difluorophenyl]-5-fluoro-2-methoxypyridi ne-3-sulfonamide [0818] Into a 40 mL vial was placed N-[3-[1-(5-cyclopropyl-3-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-4-yl)imidazo[1,5-a]py razin-6-yl]-2,4- difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (100 mg, 0.15 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred overnight then concentrated. The crude product was purified by Prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 10-55% MeCN / 0.1% aqueous ammonia; to give N-[3-[1-(5-cyclopropyl-3H-imidazol-4-yl)imidazo[1,5-a]pyrazi n- 6-yl]-2,4-difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfo namide (55 mg, 68% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 542 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 11.73 (s, 1H), 10.42 (s, 1H), 9.58 (s, 1H), 8.55 (s, 1H), 8.49-8.40 (m, 2H), 8.03 (dd, J = 7.3, 3.0 Hz, 1H), 7.61 (s, 1H), 7.38 (td, J = 8.9, 5.9 Hz, 1H), 7.21 (dd, J = 9.7, 8.2 Hz, 1H), 3.92 (s, 3H), 3.04 (s, 1H), 0.99 (d, J = 8.2 Hz, 2H), 0.88-77 (m, 2H). Example 193: Synthesis of N-[3-[1-(4-benzyl-1H-imidazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]-2,4-difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfona mide (Compound 178) Synthesis of 178-a: 4-benzyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole [0819] A solution of 1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole-4-carbaldehyde (2.7 g, 12 mmol, 1 equiv), and tosylhydrazine (2.2 g, 12 mmol, 1 equiv) in dioxane (100 ml) was stirred at 80 °C for 2 h. Potassium carbonate (4.95 g, 36 mmol, 3 eq) and phenylboronic (2.92 g, 24 mmol, 2 eq) were added to the reaction mixture, and this was heated at reflux for 12 h. Concentration gave a residue, which was applied to a silica gel column, eluting with PE:THF (2:1) resulting in 4-benzyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole (1.9 g, 48% yield) as a colorless oil. LCMS (ES, m/z): [M+H] ⁺ : 289 Synthesis of 178-b: 3-[1-(4-benzyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol- 2- yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluoroaniline [0820] n-BuLi in hexanes (2.6 mL, 6.6 mmol, 3 equiv, 2.5 M) was added dropwise to a solution of 4-benzyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazole (1.9 g, 6.6 mmol, 3 equiv) in THF (20 mL) at -78 °C. The mixture was stirred at -78 °C for 30 minutes and then a solution of ZnCl ₂ (6.6 mL, 6.6 mmol, 3 equiv, 1 M in Et ₂ O) was added dropwise at -78 °C. The reaction mixture was allowed to warm to room temperature over 30 minutes, and 2,4- difluoro-3-[1-iodoimidazo[1,5-a]pyrazin-6-yl]aniline (800 mg, 2.2 mmol, 1 equiv) and Pd(PPh ₃ ) ₄ (497 mg, 0.44 mmol, 0.2 equiv) were added. The reaction was heated at 60 °C for 1 h, then cooled and quenched by the addition of methanol (5 mL). Concentration gave a residue, which was applied to a silica gel column, eluting with PE:EA (40:60) to give 3-[1-(4- benzyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imi dazo[1,5-a]pyrazin-6-yl]-2,4- difluoroaniline (630 mg, 44% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 533 Synthesis of 178-c: N-[3-[1-(4-benzyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidaz ol-2- yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluorophenyl]-5-fluoro- 2-methoxypyridine-3- sulfonamide [0821] Into an 8 mL round-bottom flask was placed 3-[1-(4-benzyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]-2,4-difluoroaniline (200 mg, 0.38 mmol, 1 equiv), pyridine (2 mL) and 5-fluoro-2-methoxypyridine-3-sulfonyl chloride (169 mg, 0.75 mmol, 2 equiv). The solution was stirred for 3 h then concentrated. The residue was applied to a silica gel column, eluting with ethyl acetate/petroleum ether (60%:40%) to give N-[3-[1-(4-benzyl-1-[[2-(trimethylsilyl)ethoxy]methyl]imidaz ol-2- yl)imidazo[1,5-a]pyrazin-6-yl]-2,4-difluorophenyl]-5-fluoro- 2-methoxypyridine-3- sulfonamide (130 mg, 38% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 722 Synthesis of Compound 178: N-[3-[1-(4-benzyl-1H-imidazol-2-yl)imidazo[1,5-a]pyrazin-6- yl]-2,4-difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfona mide [0822] Into an 8 mL round-bottom flask was placed N-[3-[1-(4-benzyl-1-[[2- (trimethylsilyl)ethoxy]methyl]imidazol-2-yl)imidazo[1,5-a]py razin-6-yl]-2,4- difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (130 mg, 0.18 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 4 h then concentrated. The crude product was purified by Flash-Prep-HPLC with the following conditions: XBridge shield RP18 OBD, 19*150 mm 5µm 10nm; Mobile Phase: 15-38% MeCN / 0.05% aqueous ammonia; to give N-[3-[1-(4-benzyl-1H-imidazol-2-yl)imidazo[1,5-a]pyrazin-6-y l]-2,4- difluorophenyl]-5-fluoro-2-methoxypyridine-3-sulfonamide (25 mg, 23% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 592 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.58 (d, J = 61.2 Hz, 1H), 10.43 (s, 1H), 9.52 (s, 1H), 8.64 (s, 1H), 8.53 (s, 1H), 8.45 (d, J = 3.0 Hz, 1H), 8.02 (dd, J = 7.3, 3.0 Hz, 1H), 7.44-7.27 (m, 5H), 7.26-7.15 (m, 2H), 6.86 (s, 1H), 3.85-4.05 (br s, 5H). Example 194: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[2-(dimethylamino)ethyl]imidazo[1,5-a]pyra zine-1-carboxamide (Compound 179) Synthesis of Compound 179: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[2-(dimethylamino)ethyl]imidazo[1,5-a]pyra zine-1-carboxamide [0823] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added (2-aminoethyl)dimethylamine (53 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The resulting mixture was stirred for 1 h then diluted with H ₂ O (50 mL) and extracted with EA (3 x 50 mL). The combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC using the following conditions: Column: shim-pack C18, 20x150 mm, 5 µm; Mobile Phase: 10-32% MeCN / 0.5% aqueous ammonia; to afford 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[2-(dimethylamino)ethyl]imidazo[1,5-a]pyra zine-1-carboxamide (60 mg, 26% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 566 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 9.52 (d, J = 1.6 Hz, 1H), 8.67 (d, J = 2.4 Hz, 2H), 8.46 – 8.32 (m, 2H), 8.06 (d, J = 2.7 Hz, 1H), 7.36 (td, J = 9.0, 5.9 Hz, 1H), 7.22 – 7.04 (m, 1H), 3.88 (s, 3H), 3.50 (q, J = 6.2 Hz, 2H), 2.70 (t, J = 6.5 Hz, 2H), 2.40 (s, 6H). Example 195: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[2-(2-oxopyrrolidin-1-yl)ethyl]imidazo[1,5 -a]pyrazine-1-carboxamide (Compound 180) Synthesis of Compound 180: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[2-(2-oxopyrrolidin-1-yl)ethyl]imidazo[1,5 -a]pyrazine-1-carboxamide [0824] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added 1-(2-aminoethyl)pyrrolidin-2- one hydrochloride (77 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv). The reaction was stirred for 1 h then diluted with H ₂ O (50 mL) and extracted with EA (3 x 50 mL). The combined organics were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: XBridge Shield RP18 OBD, 5 µm, 19*150 mm; Mobile Phase: 15-35% MeCN / 0.05% aqueous ammonia; to afford 6-[3-(5-chloro-2-methoxypyridine-3- sulfonamido)-2,6-difluorophenyl]-N-[2-(2-oxopyrrolidin-1-yl) ethyl]imidazo[1,5-a]pyrazine- 1-carboxamide (70 mg, 29% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 606 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.45 (s, 1H), 9.51 (d, J = 1.6 Hz, 1H), 8.76-8.58 (m, 2H), 8.57-8.45 (m, 2H), 8.09 (d, J = 2.6 Hz, 1H), 7.41 (td, J = 8.9, 5.8 Hz, 1H), 7.23 (td, J = 9.1, 1.6 Hz, 1H), 3.92 (s, 3H), 3.51-3.37 (m, 6H), 2.18 (dd, J = 8.7, 7.4 Hz, 2H), 2.01-1.81 (m, 2H). Example 196: Synthesis of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[4-[(dimethylamino)methyl]phenyl]imidazo[1 ,5-a]pyrazine-1- carboxamide (Compound 181) Synthesis of Compound 180: 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]-N-[4-[(dimethylamino)methyl]phenyl]imidazo[1 ,5-a]pyrazine-1- carboxamide [0825] To a stirred solution of 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6- difluorophenyl]imidazo[1,5-a]pyrazine-1-carboxylic acid (200 mg, 0.4 mmol, 1 equiv) and DIEA (156 mg, 1.2 mmol, 3 equiv) in DMF (5 mL) was added 4- [(dimethylamino)methyl]aniline (90 mg, 0.6 mmol, 1.5 equiv) and HATU (230 mg, 0.6 mmol, 1.5 equiv) at room temperature. The resulting mixture was stirred for 1 h, then diluted with H ₂ O (50 mL) and extracted with EA (3 x 50 mL). The combined organic layers were washed with brine (3 x 30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The crude product was purified by Prep-HPLC with following conditions: Column: XBridge Shield RP18 OBD, 5 µm, 19*150mm; Mobile Phase: 13-37% MeCN / 0.05% aqueous ammonia; to afford 6-[3-(5-chloro-2-methoxypyridine-3-sulfonamido)-2,6-difluoro phenyl]-N-[4- [(dimethylamino)methyl]phenyl]imidazo[1,5-a]pyrazine-1-carbo xamide (32 mg, 13% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 628 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.31 (s, 1H), 9.60 (d, J = 1.6 Hz, 1H), 8.81-8.58 (m, 2H), 8.25 (dd, J = 2.6, 1.1 Hz, 1H), 8.01 (d, J = 2.6 Hz, 1H), 7.93-7.72 (m, 2H), 7.35-7.18 (m, 3H), 6.93 (t, J = 9.2 Hz, 1H), 3.82 (s, 3H), 3.41 (s, 2H), 2.51 (p, J = 1.9 Hz, 6H). Example 197: Synthesis of 6-[3-[5-chloro-2-(2,2,2-trifluoroethoxy)pyridine-3- sulfonamido]-2,6-difluorophenyl]-N-methylimidazo[1,5-a]pyraz ine-1-carboxamide (Compound 182) Synthesis of 182-a: 3-bromo-5-chloro-2-(2,2,2-trifluoroethoxy)pyridine [0826] To a stirred solution of 3-bromo-5-chloro-2-fluoropyridine (1 g, 4.8 mmol, 1 equiv) and trifluoroethanol (1.43 g, 14 mmol, 3 equiv) in DMSO (10 mL) was added cesium carbonate (4.66 g, 14 mmol, 3 equiv) in portions at room temperature. The reaction was stirred for 2 h at 80 °C, then cooled and quenched with H ₂ O (30 mL). The mixture was extracted with EtOAc (3 x 10 mL), and the combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE/EtOAc (50:1) to afford 3-bromo-5-chloro-2-(2,2,2- trifluoroethoxy)pyridine (1.2 g, 87% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 290, 292 Synthesis of 182-b: 3-(benzylsulfanyl)-5-chloro-2-(2,2,2-trifluoroethoxy)pyridin e [0827] To a stirred solution of 3-bromo-5-chloro-2-(2,2,2-trifluoroethoxy)pyridine (600 mg, 2.1 mmol, 1 equiv), benzyl mercaptan (385 mg, 3.1 mmol, 1.5 equiv) and DIEA (534 mg, 4.1 mmol, 2 equiv) in toluene (10 mL) were added XantPhos (239 mg, 0.41 mmol, 0.2 equiv) and Pd ₂ (dba) ₃ .CHCl ₃ (214 mg, 0.21 mmol, 0.1 equiv) in portions at room temperature under nitrogen atmosphere. The reaction was stirred for 5 h at 115 °C, then cooled and quenched with H ₂ O (30 mL). The resulting mixture was extracted with EtOAc (3 x 10 mL), and the combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 40-80% MeCN / 0.1% aqueous formic acid to afford 3-(benzylsulfanyl)-5-chloro-2-(2,2,2- trifluoroethoxy)pyridine (500 mg, 73% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 334 Synthesis of 182-c: 5-chloro-2-(2,2,2-trifluoroethoxy)pyridine-3-sulfonyl chloride [0828] To a stirred solution of 3-(benzylsulfanyl)-5-chloro-2-(2,2,2-trifluoroethoxy)pyridin e (500 mg, 1.5 mmol, 1 equiv) in HOAc (9 mL) and H ₂ O (3 mL) was added NCS (700 mg, 5.2 mmol, 3.5 equiv) in portions at 0 °C. The resulting mixture was quenched with H ₂ O (20 mL) and extracted with EtOAc (3 x 10 mL). The combined organics were washed with saturated NaHCO ₃ solution (40 mL) and brine (1 x 20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated to give crude 5-chloro-2-(2,2,2-trifluoroethoxy)pyridine-3-sulfonyl chloride (650 mg) as a white solid. Synthesis of Compound 182: 6-[3-[5-chloro-2-(2,2,2-trifluoroethoxy)pyridine-3- sulfonamido]-2,6-difluorophenyl]-N-methylimidazo[1,5-a]pyraz ine-1-carboxamide [0829] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (176 mg, 0.58 mmol, 0.3 equiv) in pyridine (5 mL) was added 5- chloro-2-(2,2,2-trifluoroethoxy)pyridine-3-sulfonyl chloride (600 mg, 1.9 mmol, 1 equiv) in DCM (0.5 mL) dropwise. The reaction was stirred for 2 h, then quenched with H ₂ O (30 mL) and extracted with EtOAc (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by prep- HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm; Mobile Phase: 30-70% MeCN / 0.1% aqueous formic acid; to afford 6-[3-[5-chloro-2-(2,2,2- trifluoroethoxy)pyridine-3-sulfonamido]-2,6-difluorophenyl]- N-methylimidazo[1,5- a]pyrazine-1-carboxamide (110 mg, 33% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 577 1H NMR (300 MHz, DMSO-d ₆ ) δ 10.51 (s, 1H), 9.51 (d, J = 1.7 Hz, 1H), 8.65 (d, J = 7.4 Hz, 2H), 8.49 (d, J = 2.6 Hz, 1H), 8.41 (q, J = 4.8 Hz, 1H), 8.18 (d, J = 2.6 Hz, 1H), 7.38 (td, J = 9.1, 5.9 Hz, 1H), 7.13 (t, J = 8.6 Hz, 1H), 5.08 (q, J = 8.9 Hz, 2H), 2.84 (d, J = 4.8 Hz, 3H). Example 198: Synthesis of 6-[3-[2-(benzyloxy)-5-chloropyridine-3-sulfonamido]-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide (Compound 183) Synthesis of 183-a: 2-(benzyloxy)-3-bromo-5-chloropyridine [0830] A solution of 3-bromo-5-chloropyridin-2-ol (1 g, 4.8 mmol, 1 equiv), BnBr (0.9 g, 5.28 mmol, 1.1 equiv) and Ag ₂ CO ₃ (1.46 g, 5.3 mmol, 1.1 equiv) in toluene (10 mL) was stirred for 1 h at 115 °C. The reaction was cooled and quenched with H ₂ O (20 mL), then extracted with EtOAc (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep- HPLC using the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 40-90% MeCN / 0.1% aqueous formic acid to afford 2- (benzyloxy)-3-bromo-5-chloropyridine (640 mg, 45% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 298, 300 Synthesis of 183-b: 2-(benzyloxy)-3-(benzylsulfanyl)-5-chloropyridine [0831] To a stirred solution of 2-(benzyloxy)-3-bromo-5-chloropyridine (600 mg, 2.0 mmol, 1 equiv), XantPhos (233 mg, 0.4 mmol, 0.2 equiv) and benzyl mercaptan (374 mg, 3.0 mmol, 1.5 equiv) in toluene (10 mL) were added DIEA (520 mg, 4.0 mmol, 2 equiv) and Pd ₂ (dba) ₃ .CHCl ₃ (208 mg, 0.2 mmol, 0.1 equiv) in portions at room temperature under nitrogen atmosphere. The resulting mixture was stirred for 5 h at 115 °C, then cooled and quenched with H ₂ O (30 mL). The resulting biphasic mixture was extracted with EtOAc (3 x 10 mL), and the combined organics were washed with brine (30 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by Flash-Prep-HPLC with the following conditions: Column, WelFlash TM C18-I, Spherical C1820-40 μm, 120 g; mobile phase: 50- 95% MeCN / 0.1% aqueous formic acid to afford 2-(benzyloxy)-3-(benzylsulfanyl)-5- chloropyridine (680 mg, 99% yield) as a light yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 342 Synthesis of 183-c: 2-(benzyloxy)-5-chloropyridine-3-sulfonyl chloride [0832] To a stirred solution of 2-(benzyloxy)-3-(benzylsulfanyl)-5-chloropyridine (690 mg, 2.02 mmol, 1 equiv) in HOAc (9 mL) and H ₂ O (3 mL) was added NCS (943 mg, 7.1 mmol, 3.5 equiv) in portions at 0 °C. The resulting mixture was stirred for 0.5 h at room temperature, then quenched with H ₂ O (20 mL) and extracted with EtOAc (3 x 10 mL). The combined organics were washed with NaHCO ₃ (40 mL) and brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated to afford crude 2-(benzyloxy)-5-chloropyridine-3- sulfonyl chloride (1.1 g) as an off-white oil which was used in the next step directly without further purification. Synthesis of Compound 183: 6-[3-[2-(benzyloxy)-5-chloropyridine-3-sulfonamido]-2,6- difluorophenyl]-N-methylimidazo[1,5-a]pyrazine-1-carboxamide [0833] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-N-methylimidazo[1,5- a]pyrazine-1-carboxamide (172 mg, 0.57 mmol, 0.3 equiv) in pyridine (6 mL) was added 2- (benzyloxy)-5-chloropyridine-3-sulfonyl chloride (600 mg, 1.9 mmol, 1 equiv) in DCM (0.6 mL) dropwise. The reaction was stirred for 2 h at room temperature. The resulting mixture was quenched with H ₂ O (20 mL) and extracted with EtOAc (3 x 10 mL). The combined organics were washed with brine (20 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 µm: Mobile Phase: 30-75% MeCN / 0.1% aqueous formic acid; to afford 6-[3-[2-(benzyloxy)-5-chloropyridine-3-sulfonamido]-2,6-difl uorophenyl]-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (110 mg, 10% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 585 1H NMR (300 MHz, DMSO-d ₆ ) δ 10.46 (s, 1H), 9.52 (d, J = 1.8 Hz, 1H), 8.68 (s, 1H), 8.57- 8.47 (m, 2H), 8.43 (q, J = 4.7 Hz, 1H), 8.16 (d, J = 2.6 Hz, 1H), 7.44-7.32 (m, 3H), 7.37-7.19 (m, 3H), 7.10 (td, J = 9.0, 1.6 Hz, 1H), 5.50 (s, 2H), 2.88-2.81 (m, 3H). Example 199: Synthesis of 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-5-fluoro-N-methylimidazo[1,5-a]pyrazine- 1-carboxamide (Compound 184) Synthesis of Compound 184: 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3- sulfonamido)phenyl]-5-fluoro-N- methylimidazo[1,5-a]pyrazine-1-carboxamide [0834] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-5-fluoro-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (60 mg, 0.2 mmol, 1 equiv) in pyridine (3 mL) was added 5-fluoro-2-methylpyridine-3-sulfonyl chloride (78 mg, 0.4 mmol, 2 equiv) in portions at room temperature. The resulting mixture was stirred overnight, then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 μm; Mobile Phase: 27-46% MeCN / 0.1% aqueous formic acid; to give 6-[2,6-difluoro-3-(5-fluoro-2-methylpyridine-3-sulfonamido)p henyl]-5-fluoro- N-methylimidazo[1,5-a]pyrazine-1-carboxamide (51 mg, 55% yield) as an off-white solid. LCMS (ES, m/z): [M+H] ⁺ : 495 1H NMR (300 MHz, DMSO-d ₆ ) δ 10.83 (s, 1H), 9.35 (d, J = 2.8 Hz, 1H), 8.91 (s, 1H), 8.72 (d, J = 2.8 Hz, 1H), 8.54 (q, J = 4.7 Hz, 1H), 7.92 (dd, J = 8.2, 2.8 Hz, 1H), 7.50 (td, J = 8.9, 5.8 Hz, 1H), 7.30 (td, J = 9.1, 1.5 Hz, 1H), 2.85 (d, J = 4.7 Hz, 3H), 2.78 (d, J = 1.2 Hz, 3H). Example 200: Synthesis of N-(2,4-difluoro-3-[1-[5-(4-methylpiperazin-1-yl)-3H-1,3- benzodiazol-2-yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-5-fluoro -2-methoxypyridine-3- sulfonamide (Compound 185) Synthesis of 185-a: 6-bromo-1-[[2-(trimethylsilyl) ethoxy]methyl]-1,3-benzodiazole [0835] To a solution of 5-bromo-3H-1,3-benzodiazole (5 g, 25 mmol, 1 equiv) in THF (130 mL) cooled in an ice bath was added NaH (1 g, 30 mmol, 1.2 equiv, 60% in oil) in portions. The mixture was stirred for 30 min at 0 °C, then SEM-Cl (5 g, 30 mmol, 1.2 equiv) was added dropwise. The ice bath was removed and the solution was stirred for 1 h. Water (100 mL) was added and the mixture extracted with ethyl acetate (3x100 mL). The combined organics were washed with brine (100 mL), dried over anhydrous Na ₂ SO ₄ and concentrated. The residue was purified by silica gel column chromatography, eluting with PE:EA (4:1) to afford 6-bromo-1-[[2-(trimethylsilyl) ethoxy]methyl]-1,3-benzodiazole (7 g, 86% yield) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 327, 329 Synthesis of 185-b: 6-(4-methylpiperazin-1-yl)-1-[[2-(trimethylsilyl)ethoxy]meth yl]-1,3- benzodiazole [0836] Into a 250 mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen was placed 6-bromo-1-[[2-(trimethylsilyl)ethoxy]methyl]-1,3- benzodiazole (4 g, 12 mmol, 1 equiv), toluene (100 mL), 1-methyl-piperazine (1.2 g, 12 mmol, 1 equiv), Pd ₂ (dba) ₃ .CHCl ₃ (1.27 g, 1.2 mmol, 0.1 equiv), BINAP (0.76 g, 1.2 mmol, 0.1 equiv) and t-BuONa (3.5 g, 36 mmol, 3 equiv). The resulting solution was stirred for 12 h at 90 °C then concentrated. The residue was applied to a silica gel column, eluting with dichloromethane/methanol (1:10) to give 6-(4-methylpiperazin-1-yl)-1-[[2- (trimethylsilyl)ethoxy]methyl]-1,3-benzodiazole (2.9 g, 55% yield) as a colorless oil. LCMS (ES, m/z): [M+H] ⁺ : 347 Synthesis of 185-c: 2,4-difluoro-3-[1-[6-(4-methylpiperazin-1-yl)-1-[[2- (trimethylsilyl)ethoxy]methyl]-1,3-benzodiazol-2-yl]imidazo[ 1,5-a]pyridin-6-yl]aniline [0837] Into a 20 mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed 6-(4-methylpiperazin-1-yl)-1-[[2- (trimethylsilyl)ethoxy]methyl]-1,3-benzodiazole (1.4 g, 4.05 mmol, 3 equiv) in THF (20 mL). 2.5M n-BuLi in hexanes (1.6 mL, 4.1 mmol, 3 equiv) was added dropwise at -78 °C, and the mixture was stirred at -78 °C for 30 minutes. ZnCl ₂ solution (4.05 mL, 4.05 mmol, 3 equiv, 1 M in Et ₂ O) was added dropwise at -78°C and the reaction allowed to warm to room temperature over 30 minutes. To the mixture was added Pd(PPh ₃ ) ₄ (311 mg, 0.27 mmol, 0.2 equiv) and 2,4-difluoro-3-[1-iodoimidazo[1,5-a]pyridin-6-yl]aniline (500 mg, 1.35 mmol, 1 equiv). The resulting solution was stirred for 2 h at 60 °C, then cooled and quenched by the addition of MeOH (5 mL). The reaction was concentrated and the residue applied to a silica gel column, eluting with dichloromethane/methanol (10:1) to give 2,4-difluoro-3-[1-[6-(4- methylpiperazin-1-yl)-1-[[2-(trimethylsilyl)ethoxy]methyl]-1 ,3-benzodiazol-2- yl]imidazo[1,5-a]pyridin-6-yl]aniline (500 mg, 57% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 590 Synthesis of 185-d: methyl N-(2,4-difluoro-3-[1-[6-(4-methylpiperazin-1-yl)-1-[[2- (trimethylsilyl)ethoxy]methyl]-1H-1,3-benzodiazol-2-yl]imida zo[1,5-a]pyridin-6-yl]phenyl)- 5-fluoro-2-methoxypyridine-3-sulfonamide [0838] Into an 8 mL round-bottom flask was placed 2,4-difluoro-3-[1-[6-(4-methylpiperazin- 1-yl)-1-[[2-(trimethylsilyl)ethoxy]methyl]-1H-1,3-benzodiazo l-2-yl]imidazo[1,5-a]pyridin-6- yl]aniline (150 mg, 0.25 mmol, 1 equiv), pyridine (2 mL) and 5-fluoro-2-methoxypyridine-3- sulfonyl chloride (115 mg, 0.5 mmol, 2 equiv). The resulting solution was stirred for 3 h then concentrated under vacuum. The residue was applied to a silica gel column, eluting with dichloromethane/methanol (10:1) to give crude N-(2,4-difluoro-3-[1-[6-(4-methylpiperazin- 1-yl)-1-[[2-(trimethylsilyl)ethoxy]methyl]-1H-1,3-benzodiazo l-2-yl]imidazo[1,5-a]pyridin-6- yl]phenyl)-5-fluoro-2-methoxypyridine-3-sulfonamide (137 mg) as a yellow oil. LCMS (ES, m/z): [M+H] ⁺ : 779 Synthesis of Compound 185: methyl N-(2,4-difluoro-3-[1-[5-(4-methylpiperazin-1-yl)-3H- 1,3-benzodiazol-2-yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-5-fl uoro-2-methoxypyridine-3- sulfonamide [0839] Into an 8 mL round-bottom flask was placed N-(2,4-difluoro-3-[1-[6-(4- methylpiperazin-1-yl)-1-[[2-(trimethylsilyl)ethoxy]methyl]-1 ,3-benzodiazol-2- yl]imidazo[1,5-a]pyridin-6-yl]phenyl)-5-fluoro-2-methoxypyri dine-3-sulfonamide (137 mg, 0.18 mmol, 1 equiv), DCM (3 mL) and TFA (1 mL). The resulting solution was stirred for 2 h, then concentrated under vacuum. The crude product was purified by Flash-Prep-HPLC with the following conditions: XBridge shield RP18 OBD, 19*150mm 5µm 10nm; Mobile Phase: 20-45% MeCN / 0.05% aqueous ammonia; to give N-(2,4-difluoro-3-[1-[5-(4- methylpiperazin-1-yl)-3H-1,3-benzodiazol-2-yl]imidazo[1,5-a] pyridin-6-yl]phenyl)-5-fluoro- 2-methoxypyridine-3-sulfonamide (14 mg, 12% yield) as a yellow solid. LCMS (ES, m/z): [M+H] ⁺ : 649 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 12.47 (s, 1H), 8.61 (d, J = 3.5 Hz, 2H), 8.40 (q, J = 3.3, 2.4 Hz, 2H), 8.00 (dd, J = 7.5, 3.0 Hz, 1H), 7.34 (td, J = 8.9, 5.9 Hz, 2H), 7.21-6.89 (m, 4H), 3.90 (s, 3H), 3.14 (t, J = 5.0 Hz, 4H), 2.60 (s, 4H), 2.32 (s, 3H). Example 201: Synthesis of 6-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6- difluorophenyl]-5-fluoro-N-methylimidazo [1,5-a]pyrazine-1-carboxamide (Compound 186) Synthesis of Compound 186: 6-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6- difluorophenyl]-5-fluoro-N- methylimidazo [1,5-a]pyrazine-1-carboxamide [0840] To a stirred solution of 6-(3-amino-2,6-difluorophenyl)-5-fluoro-N- methylimidazo[1,5-a]pyrazine-1-carboxamide (60 mg, 0.2 mmol, 1 equiv) in pyridine (3 mL) was added 5-chloro-2-methylpyridine-3-sulfonyl chloride (84 mg, 0.4 mmol, 2 equiv) in portions at room temperature. The reaction was stirred overnight then concentrated. The residue was purified by prep-HPLC with the following conditions: Column, welch Vltimate XB-C18, 50x250mm, 10 μm; Mobile Phase: 31-46% MeCN / 0.1% aqueous formic acid; to give 6-[3-(5-chloro-2-methylpyridine-3-sulfonamido)-2,6-difluorop henyl]-5-fluoro-N- methylimidazo [1,5-a]pyrazine-1-carboxamide (32 mg, 34% yield) as a white solid. LCMS (ES, m/z): [M+H] ⁺ : 511 ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.83 (s, 1H), 9.35 (d, J = 2.8 Hz, 1H), 8.91 (s, 1H), 8.74 (d, J = 2.4 Hz, 1H), 8.54 (d, J = 4.9 Hz, 1H), 8.06 (d, J = 2.4 Hz, 1H), 7.49 (td, J = 9.0, 5.8 Hz, 1H), 7.28 (t, J = 9.1 Hz, 1H), 2.85 (d, J = 4.7 Hz, 3H), 2.77 (s, 3H). Table 1.

Example 202 - Biochemical Assay for Modulation (Inhibition/Activation) of GCN2 [0841] Exemplary compounds from the above Examples were tested for ability to inhibit GCN2 activity using a time resolved fluorescence energy transfer (TR-FRET) assay. Assay procedures and results are described below for Examples 16-201. Part I – Procedures for TR-FRET Assay [0842] GCN2 protein was obtained from Carna Biosciences (cat# 05-153). The protein was diluted in assay buffer (ThermoFisher Scientific, #PV6135), 2 mM dithiothreitol (DTT), to obtain a final concentration of 2 nM and 5 µL was plated in a 384-well white assay plate. Test compounds were serially diluted to 11 concentrations by 3-fold dilution in DMSO and 10 nL of stock was plated into 384 well white assay plate. DMSO was used as a vehicle control. GFP-eIF2α protein was obtained from ThermoFisher (cat# PV4809). The protein was diluted in assay buffer to a 2x concentration of 200 nM along with 300 µM ATP (final concentration of 100 nM GFP-eIF2α and 150 µM ATP) in the presence of 2 mM DTT and a 5 µL aliquot was added to each well containing the GCN2 protein and test compound. The plate was incubated in the dark at 25 ^o C for 1.5 hours, shaking at 1250 rpm. Tb-anti P-eIF2α (ThermoFisher cat# PV4815) was diluted to a to a concentration of 1 nM in TR-FRET Dilution Buffer (ThermoFisher cat# PV3574).10 µL of the Tb-anti P-eIF2α solution was added to the TR-FRET reaction. The plate was incubated in the dark for 2 h at 25 ^o C shaking at 600 rpm. The FRET signal from the plate was read on a Envision (PerkinElmer) plate reader: [0843] Label 1: Excitation: 340 nm, bandwidth 30 nm; Emission: 495 nm, bandwidth 10 nm. Lag time: 100 μsec. Integration time: 400 μsec. Flashes: 30. [0844] Label 2: Excitation: 340 nm, bandwidth 30 nm; Emission: 520 nm, bandwidth 25 nm. Lag time: 100 μsec. Integration time: 400 μsec. Flashes: 30 [0845] The data were analyzed using GraphPad Prism employing a 4-parameter sigmoidal curve fit. Part II – Results [0846] Experimental results are provided in Table 2 below. The symbol “++++” indicates an IC ₅₀ less than 0.0500 µM. The symbol “+++” indicates an IC ₅₀ in the range of 0.0500 µM to 0.5000 µM. The symbol “++” indicates an IC ₅₀ in the range of greater than 0.5000 µM to 1.0000 µM. The symbol “+” indicates an IC ₅₀ greater than 1.0000 µM. The symbol “N/A” indicates that no data was available. Table 2.

INCORPORATION BY REFERENCE [0847] The entire disclosure of each of the patent documents and scientific articles referred to herein is incorporated by reference for all purposes. EQUIVALENTS [0848] The disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting the disclosure described herein. Scope of the disclosure is thus indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.