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Title:
AZA-BENZOTHIOPHENE COMPOUNDS AS STING AGONISTS
Document Type and Number:
WIPO Patent Application WO/2019/195063
Kind Code:
A1
Abstract:
Compounds of general formula (I), and their pharmaceutically acceptable salts, wherein R1, R2, R3, R5, R6, R8, R9, A, X1, X2, and X3 are defined herein, that may be useful as inductors of type I interferon production, specifically as STING active agents, are provided. Also provided are compositions comprising such compounds, processes for the synthesis of such compounds, and to uses of such compounds, including administration of such compounds to induce immune response, to induce STING-dependent type I interferon production, and/or to treat a cell proliferation disorder, such as cancer.

Inventors:
ALTMAN MICHAEL (US)
CASH BRANDON (US)
CUMMING JARED (US)
DEMONG DUANE (US)
HAIDLE ANDREW (US)
JEWELL JAMES (US)
LARSEN MATTHEW (US)
LU MIN (US)
OTTE RYAN (US)
TAOKA BRANDON (US)
TROTTER BENJAMIN WESLEY (US)
TRUONG QUANG (US)
Application Number:
PCT/US2019/024455
Publication Date:
October 10, 2019
Filing Date:
March 28, 2019
Export Citation:
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Assignee:
MERCK SHARP & DOHME (US)
ALTMAN MICHAEL D (US)
CASH BRANDON D (US)
CUMMING JARED N (US)
DEMONG DUANE E (US)
HAIDLE ANDREW M (US)
JEWELL JAMES P (US)
LARSEN MATTHEW A (US)
LU MIN (US)
OTTE RYAN D (US)
TAOKA BRANDON M (US)
TROTTER BENJAMIN WESLEY (US)
TRUONG QUANG T (US)
International Classes:
C07D333/64; C07D409/06; C07D409/12
Foreign References:
US8343967B22013-01-01
US4952571A1990-08-28
US20060194821A12006-08-31
US4342689A1982-08-03
US20180093964A12018-04-05
Other References:
See also references of EP 3774765A4
Attorney, Agent or Firm:
MERCK SHARP & DOHME CORP. (US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. A compound of formula (I):

or a pharmaceutically acceptable salt thereof, wherein

each A-R1 is sepected independently from the group consisting of C-R1 and N, and at least one A-R1 is CH;

each R1 is selected independently from the group consisting of H, halogen, OR6, N(R6)2, SR6, Ci-C6 alkyl, Ci-C6 haloalkyl, C C6 alkyl substituted by OR6, Ci-C6 alkyl substituted by SR6, Ci-C6 alkyl substituted by N(R6)2, Ci-C6 haloalkyl substituted by OR6, Ci-C6 haloalkyl substituted by SR6, and Ci-C6 haloalkyl substituted by N(R6)2;

R2 is selected from the group consisting of H, halogen, CN, OR6, N(R6)2, COOR6, C(0)N(R6)2, SR6, S02R6, CI-C6 alkyl, Ci-C6 haloalkyl, C2-C6 alkenyl, C2-C6 haloalkenyl, C2-C6 alkynyl, C2-G, haloalkynyl, C3-C6 cycloalkyl, and a 3- to 6-membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, N, and N(R6), wherein said Ci-C6 alkyl, Ci-C6 haloalkyl, C2-C6 alkenyl, C2-C6 haloalkenyl, C2-C6 alkynyl, C2-C6 haloalkynyl, C3-C6 cycloalkyl, and 3- to 6-membered heterocyclic ring groups are optionally substituted by one or more substituents independently selected from the group consisting of CN, OR6, N(R6)2, and SR6, and wherein said C3-C6 cycloalkyl and 3- to 6-membered heterocyclic ring are each further optionally substituted with a member of the group consisting of C1-C3 alkyl and C1-C3 haloalkyl;

R3 is selected from the group consisting of H, halogen, CN, OR6, N(R6)2, COOR6, C(0)N(R6)2, SR6, S02R6, CI-C6 alkyl, Ci-C6 haloalkyl, C2-C6 alkenyl, C2-C6 haloalkenyl, C2-C6 alkynyl, CVG, haloalkynyl, C3-C6 cycloalkyl, and a 3- to 6-membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, N, and N(R6), wherein said Ci-C6 alkyl, Ci-C6 haloalkyl, C2-C6 alkenyl, C2-C6 haloalkenyl, C2-C6 alkynyl, C2-C6 haloalkynyl, C3-C6 cycloalkyl, and 3- to 6-membered heterocyclic ring groups are optionally substituted by one or more substituents independently selected from the group consisting of CN, OR6, N(R6)2, and SR6, and wherein said C3-C6 cycloalkyl and 3- to 6-membered heterocyclic ring are each further optionally substituted with a member of the group consisting of C1-C3 alkyl and C1-C3 haloalkyl;

optionally R3 and an adjacent A-R1 may be taken together with the atoms to which they are attached form a fused 5- or 6-membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, N, and N(R6) wherein said heterocyclic ring is optionally substituted with or more members of the group consisting of C1-C3 alkyl and C1-C3 haloalkyl;

each R6 is independently selected from the group consisting of H, Ci-C6 alkyl, and Ci-C6 haloalkyl, wherein said Ci-C6 alkyl, and Ci-C6 haloalkyl are optionally substituted with OH, 0(Ci-C3 alkyl), and 0(Ci-C3 haloalkyl);

X1 is selected from the group consisting of CH2 and C(O);

X2 is (C(R8)2)(I.3);

each R8 is independently selected from the group consisting of H, halogen, CN, OR6, N(R6)2, SR6, Ci-C6 alkyl, Ci-C6 haloalkyl, C3-C6 cycloalkyl, and a 3- to 6-membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, N, and N(R6), wherein said Ci-C6 alkyl, Ci-C6 haloalkyl, C2-C6 alkenyl, C2-C6 haloalkenyl, C2-C6 alkynyl, CVG, haloalkynyl, C3-C6 cycloalkyl, and 3- to 6-membered heterocyclic ring groups are optionally substituted by one or more substituents independently selected from the group consisting of CN, OR6, N(R6)2, and SR6, and wherein said C3-C6 cycloalkyl and 3- to 6- membered heterocyclic ring are each further optionally substituted with a member of the group consisting of C1-C3 alkyl and C1-C3 haloalkyl;

optionally 2 R8 on different carbon atoms may be taken together, along with the atoms to which they are attached, to form a 3- to 6-membered fused ring;

optionally 2 R8 on a single carbon atom may be taken together, along with the atom to which they are attached, to form a 3- to 6-membered spirocycle;

X3 is selected from the group consisting of COOR6, HO' . C(0)SR6,

C(S)OR6, S02R6, and C(0)N(R9)2; and

each R9 is independently selected from the group consisting of H, COOR6, and

S02R6.

2. The compound according to claim 1, or a pharmaceutically acceptable salt

thereof, wherein selected from the group consisting

3. The compound according to claim 2, or a pharmaceutically acceptable salt

thereof, wherein selected from the group consisting of

4. The compound according to claim 1 or claim 2, or a pharmacuetically acceptable salt thereof, wherein each R1 is selected independently from the group consisting of H, F, Cl, Ci-C3 alkyl, and Ci-C3 haloalkyl.

5. The compound according to claim 4, or a pharmaceutically acceptable salt thereof, wherein each R1 is selected independently from the group consisting of H and F.

6. The compound according to any one of claims 1 to 5, or a pharmacueitically acceptable salt thereof, wherein R2 is selected from the group consisting of halogen, Ci-C3 alkyl, Ci-C3 haloalkyl, OCi-C3 alkyl, C2-C3 alkenyl, and N(R6)2.

7. The compound according to any one of claims 1 to 6, or a pharmaceutically acceptable salt thereof, wherein R2 is selected from the group consisting of Br, Cl, CH3, CH2CH3, CH=CH2, OCH3, and N(R6)2.

8. The compound according to any one of claims 1 to 7, or a pharmacueitically acceptable salt thereof, wherein R3 is selected from the group consisting of halogen, C1-C3 alkyl, C1-C3 haloalkyl, OC1-C3 alkyl, C2-C3 alkenyl, and N(R6)2.

9. The compound according to any one of claims 1 to 8, or a pharmaceutically acceptable salt thereof, wherein R3 is selected from the group consisting of Br, Cl, CH3, CH2CH3, CH=CH2, 0CH3, and N(R6)2.

10. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein

selected from the group consisting

each R1 is selected independently from the group consisting of H, F, Cl, C1-C3 alkyl, and C1-C3 haloalkyl;

R2 is selected from the group consisting of halogen, C1-C3 alkyl, C1-C3 haloalkyl, OC1-C3 alkyl, C2-C3 alkenyl, and N(R6)2;

R3 is selected from the group consisting of halogen, C1-C3 alkyl, C1-C3 haloalkyl, OC1-C3 alkyl, C2-C3 alkenyl, and N(R6)2;

X'-X2-X3 is selected from the group consisting of C(0)-CH2CHR8-C00R6, C(O)- CH2CHR8-S02R6, and C(0)-CH2CHR8-C(0)N(R9)2;

each R6 is independently selected from the group consisting of H, C1-C3 alkyl, and C1-C3 haloalkyl; and

each R8 is selected from the group consisting of H, C1-C3 alkyl, C1-C3 alkyl substituted by OH, C1-C3 alkyl substituted by OC1-C3 alkyl, and C3-C6 cycloalkyl.

11. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein selected from the group consisting

each R1 is selected from the group consisting of H and F;

R2 is selected from the group consisting of Br, Cl, CH3, CH2CH3, CH=CH2, OCH3, and N(R6)2;

R3 is selected from the group consisting of Br, Cl, CH3, CH2CH3, CH=CH2, OCH3, and N(R6)2;

X3-X2-X3 is C(0)-CH2CHR8-C00H;

each R6 is independently selected from the group consisting of H and CH3;

R8 is selected from the group consisting of H, CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2OCH3, and cyclopropyl.

12. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein

selected from the group consisting of

R2 is selected from the group consisting of Br, Cl, CH3, CH2CH3, CH=CH2, OCH3, and N(R6)2;

R3 is selected from the group consisting of Br, Cl, CH3, CH2CH3, CH=CH2, OCH3, and N(R6)2;

X3-X2-X3 is C(0)-CH2CHR8-C00H;

each R6 is independently selected from the group consisting of H and CH3; R8 is selected from the group consisting of H, CH3, CH2CH3, CH2CH2CH3,

CH(CH3)2, CH2OCH3, and cyclopropyl.

13. A compound selected from the group consisting of:

pharmaceutically acceptable salts thereof.

14. A pharmaceutical composition, said pharmaceutical composition comprising a compound according to any one of claims 1 to 13, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

15. A method of inducing an immune response in a patient in need of therapy, said method comprising:

(a) administering a therapeutically effective amount of a compound according to any one of claims 1 through 13, or a pharmaceutically acceptable salt thereof, to the patient.

16. A method of inducing an immune response in a patient in need of therapy, said method comprising:

(a) administering a therapeutically effective amount of a

pharmaceutical composition according to claim 14 to the patient.

17. A method of inducing STING-dependent type I interferon production in a patient in need of therapy, said method comprising administering a therapeutically effective amount of a compound according to any one of claims 1 through 13, or a pharmaceutically acceptable salt thereof, to the patient.

18. A method of inducing STING-dependent type I interferon production in a patient in need of therapy, said method comprising administering a therapeutically effective amount of a pharmaceutical composition according to claim 14 to the patient.

19. A method of treating a cell proliferation disorder in a patient in need of therapy, said method comprising administering a therapeutically effective amount of a compound according to any one of claims 1 through 13, or a pharmaceutically acceptable salt thereof, to the patient.

20. The method of claim 19, wherein the cell proliferation disorder is cancer.

21. A method of treating a cell proliferation disorder in a patient in need of therapy, said method comprising administering a therapeutically effective amount of a pharmaceutical composition according to claim 14 to the patient.

22. The method of claim 21, wherein the cell proliferation disorder is cancer.

Description:
TITLE OF THE APPLICATION

AZA-BENZOTHIOPHENE COMPOUNDS AS STING AGONISTS

FIELD OF THE INVENTION

The present disclosure relates to compounds and derivatives thereof that may be useful as STING (Stimulator of Interferon Genes) agonists that activate the STING pathway.

The present disclosure also relates to compositions comprising such compounds, processes for the synthesis of such compounds, and to uses of such compounds, including administration of such compounds to induce immune response, to induce STING-dependent type I interferon production, and/or to treat a cell proliferation disorder, such as cancer.

REFERENCE TO SEQUENCE LISTING SUBMITTED ELECTRONICALLY

The sequence listing of the present application is submitted electronically via EFS-Web as an ASCII-formatted sequence listing, with a file name of“24577-SEQLIST- MARCH20l9.txt”, a creation date of March 11, 2019, and a size of 13KB. This sequence listing submitted via EFS-Web is part of the specification and is herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The immune system has evolved to recognize and neutralize different types of threats in order to maintain the homeostasis of the host, and it is generally broken down into two arms: adaptive and innate. The adaptive immune system is specialized to recognize as foreign those antigens not naturally expressed in the host and to mount an anti-antigen response through the coordinated actions of many leukocyte subsets. The hallmark of adaptive immune responses is their ability to provide“memory” or long-lasting immunity against the encountered antigen. While this specific and long-lasting effect is critical to host health and survival, the adaptive immune response requires time to generate a full-blown response.

The innate immune system compensates for this time delay and is specialized to act quickly against different insults or danger signals. It provides the first line of defense against bacteria, viruses, parasites and other infectious threats, but it also responds strongly to certain danger signals associated with cellular or tissue damage. The innate immune system has no antigen specificity but does respond to a variety of effector mechanisms. Opsonization, phagocytosis, activation of the complement system, and production of soluble bioactive molecules such as cytokines or chemokines are all mechanisms by which the innate immune system mediates its response. By responding to these damage-associated molecular patterns (DAMPs) or pathogen-associated molecular patterns (PAMPs) described above, the innate immune system is able to provide broad protection against a wide range of threats to the host.

Free cytosolic DNA and RNA are among these PAMPs and DAMPs. It has recently been demonstrated that the main sensor for cytosolic DNA is cGAS (cyclic GMP-AMP synthase). Upon recognition of cytosolic DNA, cGAS catalyzes the generation of the cyclic- dinucleotide 2’3’-cGAMP, an atypical second messenger that strongly binds to the ER- transmembrane adaptor protein STING. A conformational change is undergone by cGAMP- bound STING, which translocates to a perinuclear compartment and induces the activation of critical transcription factors IRF-3 and NF-kB. This leads to a strong induction of type I interferons and production of pro-inflammatory cytokines such as IL-6, TNF-a and IFN-g.

The importance of type I interferons and pro-inflammatory cytokines on various cells of the immune system has been very well established. In particular, these molecules strongly potentiate T-cell activation by enhancing the ability of dendritic cells and macrophages to uptake, process, present and cross-present antigens to T-cells. The T-cell stimulatory capacity of these antigen-presenting cells is augmented by the up-regulation of critical co-stimulatory molecules, such as CD80 or CD86. Finally, type I interferons can rapidly engage their cognate receptors and trigger the activation of interferon-responsive genes that can significantly contribute to adaptive immune cell activation.

From a therapeutic perspective, type I interferons are shown to have antiviral activities by directly inhibiting human hepatitis B virus and hepatitis C virus replication, and by stimulating immune responses to virally infected cells. Compounds that can induce type I interferon production are used in vaccines, where they act as adjuvants, enhancing specific immune responses to antigens and minimizing side effects by reducing dosage and broadening the immune response.

In addition, interferons, and compounds that can induce interferon production, have potential use in the treatment of human cancers. Such molecules are potentially useful as anti-cancer agents with multiple pathways of activity. Interferons can inhibit human tumor cell proliferation directly and may be synergistic with various approved chemotherapeutic agents. Type I interferons can significantly enhance anti-tumor immune responses by inducing activation of both the adaptive and innate immune cells. Finally, tumor invasiveness may be inhibited by interferons by modulating enzyme expression related to tissue remodeling. In view of the potential of type I interferons and type I interferon-inducing compounds as anti-viral and anti-cancer agents, there remains a need for new agents that can induce potent type I interferon production. With the growing body of data demonstrating that the cGAS-STING cytosolic DNA sensory pathway has a significant capacity to induce type I interferons, the development of STING activating agents is rapidly taking an important place in today’s anti -tumor therapy landscape.

SUMMARY OF THE INVENTION

The present disclosure relates to novel compounds of general formula (I). In particular, the present disclosure relates to compounds having the general structural formula (I):

or pharmaceutically acceptable salts thereof, as described herein. Uses of compounds of general formula (I) and processes for making compounds of general formula (I) are also disclosed.

Other embodiments, aspects and features of the present disclosure are either further described in or will be apparent from the ensuing description, examples and appended claims.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure includes compounds of general formula (I), and pharmaceutically acceptable salts thereof. These compounds and their pharmaceutically acceptable salts may be useful as agents to induce immune responses, to induce STING- dependent type I interferon production, and/or to treat a cell proliferation disorder.

In particular, the disclosure relates to compounds of general formula (I):

or a pharmaceutically acceptable salt thereof, wherein each A-R 1 is sepected independently from the group consisting of C-R 1 and N, and at least one A-R 1 is CH; each R 1 is selected

independently from the group consisting ofH, halogen, OR 6 , N(R 6 ) 2 , SR 6 , Ci-C 6 alkyl, Ci-C 6 haloalkyl, Ci-C 6 alkyl substituted by OR 6 , Ci-C 6 alkyl substituted by SR 6 , Ci-C 6 alkyl substituted by N(R 6 ) 2 , Ci-C 6 haloalkyl substituted by OR 6 , C i -G, haloalkyl substituted by SR 6 , and Ci-C 6 haloalkyl substituted by N(R 6 ) 2 ; R 2 is selected from the group consisting of H, halogen, CN, OR 6 , N(R 6 ) 2 , COOR 6 , C(0)N(R 6 ) 2 , SR 6 , S0 2 R 6 , Ci-C 6 alkyl, Ci-C 6 haloalkyl, C 2 - Ce alkenyl, C 2 -C 6 haloalkenyl, C 2 -C 6 alkynyl, C 2 -C 6 haloalkynyl, C 3 -C 6 cycloalkyl, and a 3- to 6- membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, N, and N(R 6 ), wherein said Ci-C 6 alkyl, Ci-C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 2 -C 6 alkynyl, C 2 -C 6 haloalkynyl, C 3 -C 6 cycloalkyl, and 3- to 6-membered heterocyclic ring groups are optionally substituted by one or more substituents independently selected from the group consisting of CN, OR 6 , N(R 6 ) 2 , and SR 6 , and wherein said C 3 -C 6 cycloalkyl and 3- to 6- membered heterocyclic ring are each further optionally substituted with a member of the group consisting of C 1 -C 3 alkyl and C 1 -C 3 haloalkyl; R 3 is selected from the group consisting of H, halogen, CN, OR 6 , N(R 6 ) 2 , COOR 6 , C(0)N(R 6 ) 2 , SR 6 , S0 2 R 6 , Ci-C 6 alkyl, C C 6 haloalkyl, C 2 - Ce alkenyl, C 2 -C 6 haloalkenyl, C 2 -C 6 alkynyl, C 2 -C 6 haloalkynyl, C 3 -C 6 cycloalkyl, and a 3- to 6- membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, N, and N(R 6 ), wherein said Ci-C 6 alkyl, Ci-C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 2 -C 6 alkynyl, C 2 -C 6 haloalkynyl, C 3 -C 6 cycloalkyl, and 3- to 6-membered heterocyclic ring groups are optionally substituted by one or more substituents independently selected from the group consisting of CN, OR 6 , N(R 6 ) 2 , and SR 6 , and wherein said C 3 -C 6 cycloalkyl and 3- to 6- membered heterocyclic ring are each further optionally substituted with a member of the group consisting of C 1 -C 3 alkyl and C 1 -C 3 haloalkyl; optionally R 3 and an adjacent A-R 1 may be taken together with the atoms to which they are attached form a 5- or 6-membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, N, and N(R 6 ) wherein said heterocyclic ring is optionally substituted with or more members of the group consisting of C 1 -C 3 alkyl and C 1 -C 3 haloalkyl; each R 6 is independently selected from the group consisting of H, Ci-C 6 alkyl, and Ci-C 6 haloalkyl, wherein said Ci-C 6 alkyl, and Ci-C 6 haloalkyl are optionally substituted with OH, 0(Ci-C 3 alkyl), and 0(Ci-C 3 haloalkyl); X 1 is selected from the group consisting of CH 2 and C(O); X 2 is (C(R 8 ) 2 ) (i-3) ; each R 8 is independently selected from the group consisting of H, halogen, CN, OR 6 , N(R 6 ) 2 , SR 6 , Ci-C 6 alkyl, Ci-C 6 haloalkyl, C 3 -C 6 cycloalkyl, and a 3- to 6-membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, N, and N(R 6 ), wherein said Ci-C 6 alkyl, Ci-C 6 haloalkyl, C 2 - Ce alkenyl, C 2 -C 6 haloalkenyl, C 2 -C 6 alkynyl, C 2 -C 6 haloalkynyl, C 3 -C 6 cycloalkyl, and 3- to 6- membered heterocyclic ring groups are optionally substituted by one or more substituents independently selected from the group consisting of CN, OR 6 , N(R 6 ) 2 , and SR 6 , and wherein said C 3 -C 6 cycloalkyl and 3- to 6-membered heterocyclic ring are each further optionally substituted with a member of the group consisting of C 1 -C 3 alkyl and C 1 -C 3 haloalkyl; optionally 2 R 8 on different carbon atoms may be taken together, along with the atoms to which they are attached, to form a 3- to 6-membered fused ring; optionally 2 R 8 on a single carbon atom may be taken together, along with the atom to which they are attached, to form a 3- to 6-membered spirocycle;

X 3 is selected from the group consisting of COOR 6 , HO' , C(0)SR 6 , C(S)OR 6 , S0 2 R 6 , and C(0)N(R 9 ) 2 ; and each R 9 is independently selected from the group consisting of H, COOR 6 , and S0 2 R 6 .

In a first embodiment, each A-R 1 is selected independently from the group consisting of C-R 1 and N, and at least one A-R 1 is CH. In particular aspects of this embodiment,

selected from the group consisting more particular aspects of this

embodiment, selected from the group consisting of this embodiment, all other groups are as provided in the general formula (I) above.

In a second embodiment, each R 1 is selected independently from the group consisting of H, halogen, OR 6 , N(R 6 ) 2 , Ci-C 6 alkyl, Ci-C 6 haloalkyl, Ci-C 6 alkyl substituted by OR 6 , Ci-C 6 alkyl substituted by N(R 6 ) 2 , COOR 6 , and C(0)N(R 6 ) 2 . In instances of this aspect, each R 1 is selected independently from the group consisting of H, F, Cl, C 1 -C 3 alkyl, and C 1 -C 3 haloalkyl. In particular instances of this aspect, R 1 each R 1 is selected independently from the group consisting of H and F. In this embodiment, all other groups are as provided in the general formula (I) or in the first embodiment above.

In a third embodiment, R 2 is selected from the group consisting of halogen, CN, OR 6 , N(R 6 ) 2 , COOR 6 , C(0)N(R 6 ) 2 , S0 2 R 6 , C I -C 6 alkyl, G-G haloalkyl, G-G alkyl substituted by OR 6 , G-G, alkenyl, C 2 -G, haloalkenyl, C 2 -G, alkenyl substituted by OR 6 , G-G, alkynyl, C 2 - G haloalkynyl, G-G alkynyl substituted by OR 6 , C3-C6 cycloalkyl, and a 3- to 6-membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, and N(R 6 ). In instances of this aspect, R 2 is selected from the group consisting of halogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, OC 1 -C 3 alkyl, G-G alkenyl, and N(R 6 ) 2 . In particular instances of this aspect, R 2 is selected from the group consisting of Br, Cl, CH 3 , CH 2 CH 3 , CH=CH 2 , OCH 3 , and N(R 6 ) 2 . In more particular instances of this aspect, R 2 is selected from the group consisting of Br and OCH 3 . In this embodiment, all other groups are as provided in the general formula (I) or in the first or second embodiments described above.

In a fourth embodiment, R 3 is selected from the group consisting of halogen, CN, OR 6 , N(R 6 ) 2 , COOR 6 , C(0)N(R 6 ) 2 , S0 2 R 6 , G-G alkyl, G-G haloalkyl, G-G alkyl substituted by OR 6 , G-G, alkenyl, G-G, haloalkenyl, G-G, alkenyl substituted by OR 6 , G-G, alkynyl, C 2 - G haloalkynyl, G-G alkynyl substituted by OR 6 , G-G cycloalkyl, and a 3- to 6-membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, and N(R 6 ). In instances of this aspect, R 3 is selected from the group consisting of halogen, G-G alkyl, G-G haloalkyl, OC1-C3 alkyl, G-G alkenyl, and N(R 6 ) 2 . In particular instances of this aspect, R 3 is selected from the group consisting of Br, Cl, CH 3 , CH 2 CH 3 , CH=CH 2 , OCH 3 , and N(R 6 ) 2 . In more particular instances of this aspect, R 3 is selected from the group consisting of Br, Cl, and OCH 3 . In certain embodiments, R 3 and an adjacent A-R 1 may be taken together with the atoms to which they are attached form a 5- or 6-membered heterocyclic ring including 1 to 2 ring members selected from the group consisting of O, S, N, and N(R 6 ), wherein said heterocyclic ring is optionally substituted with or more members of the group consisting of G- G alkyl and G-G haloalkyl. In this embodiment, all other groups are as provided in the general formula (I) or in the first through third embodiments described above.

In a fifth embodiment, each R 6 is selected independently from the group consisting of H, G-G alkyl, and G-G haloalkyl. In aspects of this embodiment, each R 6 is selected independently from the group consisting of H, G-G alkyl, and G-G haloalkyl. In particular aspects of this embodiment, each R 6 is selected independently from the group consisting of H and CH 3 . In this embodiment, all other groups are as provided in the general formula (I) or in the first through fourth embodiments described above.

In a sixth embodiment, X 3 is selected from the group consisting of COOR 6 ,

particular aspects of this embodiment, X 3 is COOR 6 . In even more particular aspects of this embodiment, X 3 is COOH. In this embodiment, all other groups are as provided in the general formula (I) or in the first through fifth embodiments described above.

In a seventh embodiment, each R 9 is independently selected from the group consisting of H, COOR 6 , and SO2R 6 . In instances of this embodiment, each R 9 is independently H. In this embodiment, all other groups are as provided in the general formula (I) or in the first through sixth embodiments described above.

In an eighth embodiment, X 2 is wherein each R 8 is independently selected from the group consisting of H, halogen, C 1 -C 6 alkyl, CN, OR 6 , N(R 6 ) 2 , C 1 -C 6 haloalkyl, C 3 -C 6 cycloalkyl, C 1 -C 6 alkyl substituted by OR 6 , and C 1 -C 6 alkyl substituted by N(R 6 ) 2 ;

optionally 2 R 8 on different carbon atoms may be taken together, along with the atoms to which they are attached, to form a 3- to 6-membered fused ring; optionally 2 R 8 on a single carbon atom may be taken together, along with the atom to which they are attached, to form a 3- to 6- membered spirocycle. In a first aspect of this embodiment, X 2 is CH 2 CHR 8 , where R 8 is selected from the group consisting of H, C 1 -C 3 alkyl, C 1 -C 3 alkyl substituted by OH, C 1 -C 3 alkyl substituted by OC 1 -C 3 alkyl, and C 3 -C 6 cycloalkyl. In particular instances of this first aspect, X 2 is CH 2 CHR 8 , wherein R 8 is selected from the group consisting of H, CH 3 , CH 2 OH, CH 2 CH 3 , CH 2 CH 2 CH 3 , CH(CH 3 ) 2 , CH 2 OCH 3 , and cyclopropyl. In a second aspect of this embodiment,

X 2 is CHR 8 CHR 8 , where R 8 is selected from the group consisting of H, C 1 -C 3 alkyl, C 1 -C 3 alkyl substituted by OH, C 1 -C 3 alkyl substituted by OC 1 -C 3 alkyl, and C 3 -C 6 cycloalkyl, and optionally 2 R 8 on different carbon atoms are taken together, along with the atoms to which they are attached, to form a 3- to 6-membered fused ring. In particular instances of this second aspect, X 2 is CHR 8 CHR 8 , where R 8 is selected from the group consisting of H and C 1 -C 3 alkyl, and optionally 2 R 8 on different carbon atoms may be taken together, along with the atoms to which they are attached, to form a 3- to 6-membered fused ring. In a third aspect of this embodiment, X 2 is CH 2 C(R 8 ) 2 , where R 8 is selected from the group consisting of H, C 1 -C 3 alkyl, C 1 -C 3 alkyl substituted by OH, C 1 -C 3 alkyl substituted by OC 1 -C 3 alkyl, and C 3 -C 6 cycloalkyl, and optionally 2 R 8 on a single carbon atom may be taken together, along with the atom to which they are attached, to form a 3- to 6-membered spirocycle. In particular instances of this third aspect, X 2 is CH 2 C(R 8 ) 2 , where R 8 is selected from the group consisting of H and C 1 -C 3 alkyl, and optionally 2 R 8 on a single carbon atom may be taken together, along with the atom to which they are attached, to form a 3- to 6-membered spirocycle. In this embodiment, all other groups are as provided in the general formula (I) or in the first through seventh embodiments described above.

In a ninth embodiment, X 1 is C(O) or CH 2 . In aspects of this embodiment, X 1 is C(O). In this embodiment, all other groups are as provided in the general formula (I) or in the first through eighth embodiments described above.

In a tenth embodiment, selected from the group consisting of

each R 1 is selected independently from the group consisting of H, F, Cl, C 1 -C 3 alkyl, and C 1 -C 3 haloalkyl; R 2 is selected from the group consisting of halogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, OC 1 -C 3 alkyl, C 2 -C 3 alkenyl, and N(R 6 ) 2 ; R 3 is selected from the group consisting of halogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, OC 1 -C 3 alkyl, C 2 -C 3 alkenyl, and N(R 6 ) 2 ; X 3 -X 2 -X 3 is selected from the group consisting of C(0)-CH 2 CHR 8 -C00R 6 , C(0)-CH 2 CHR 8 -S0 2 R 6 , and

C(0)-CH 2 CHR 8 -C(0)N(R 9 ) 2 ; each R 6 is independently selected from the group consisting of H, C 1 -C 3 alkyl, and C 1 -C 3 haloalkyl; and each R 8 is selected from the group consisting of H, C 1 -C 3 alkyl, C 1 -C 3 alkyl substituted by OH, C 1 -C 3 alkyl substituted by OC 1 -C 3 alkyl, and C 3 -C 6

R 2 . .A-

XXH

cycloalkyl. In instances of this aspect, is selected from the group consisting of

each R 1 is selected from the group consisting of H and F; R 2 is selected from the group consisting of Br, Cl, CH 3 , CH 2 CH 3 , CH=CH 2 , OCH 3 , and N(R 6 ) 2 ; R 3 is selected from the group consisting of Br, Cl, CH 3 , CH 2 CH 3 , CH=CH 2 , OCH 3 , and N(R 6 ) 2 ; X 3 -X 2 -X 3 is

C(0)-CH 2 CHR 8 -C00H; each R 6 is independently selected from the group consisting of H and CH 3 ; R 8 is selected from the group consisting of H, CH 3 , CH 2 CH 3 , CH 2 CH 2 CH 3 , CH(CH 3 ) 2 ,

CH 2 OCH 3 , and cyclopropyl. In still more particular instances, selected from

the group consisting

independently selected from the group consisting of H and CH 3 ; R 8 is selected from the group consisting of H, CH 3 , CH 2 CH 3 , CH 2 CH 2 CH 3 , CH(CH 3 ) 2 , CH 2 OCH 3 , and cyclopropyl. In this embodiment, all other groups are as provided in the general formula (I) or in the first through ninth embodiments described above.

An eleventh embodiment relates to a pharmaceutical composition, said pharmaceutical composition comprising (a) a compound according to general formula (I) above or the first through tenth embodiments described above or a pharmaceutically acceptable salt thereof; and (b) a pharmaceutically acceptable carrier.

A twelfth embodiment relates to methods of inducing an immune response in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound according to general formula (I) above or the first through tenth embodiments described above described above or a pharmaceutically acceptable salt thereof to the patient. A thirteenth embodiment relates to methods of inducing an immune response in a patient in need of therapy, comprising administering a therapeutically effective amount of a composition according to the eleventh aspect described above to the patient.

A fourteenth embodiment relates to methods of inducing a STING-dependent type I interferon production in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound according to general formula (I) above or the first through tenth embodiments described above or a pharmaceutically acceptable salt thereof to the patient.

A fifteenth embodiment relates to methods of inducing STING-dependent type I interferon production in a patient in need of therapy, comprising administering a therapeutically effective amount of a composition according to the eleventh aspect described above to the patient.

A sixteenth embodiment relates to methods of inducing STING-dependent cytokine production in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound according to general formula (I) above or the first through tenth embodiments described above or a pharmaceutically acceptable salt thereof to the patient.

A seventeenth embodiment relates to methods of inducing a STING-dependent cytokine production in a patient in need of therapy, comprising administering a therapeutically effective amount of a composition according to the eleventh aspect described above to the patient.

An eighteenth embodiment relates to methods of treating a cell proliferation disorder in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt thereof to the patient. In aspects of this eighteenth embodiment, the cell proliferation disorder is cancer.

A nineteenth embodiment relates to methods of treating a cell proliferation disorder in a patient in need of therapy, said method comprising administering a therapeutically effective amount of a composition according to the eleventh aspect described above to the patient. In aspects of this nineteenth embodiment, the cell proliferation disorder is cancer.

In each embodiment described herein, variables R 1 , R 2 , R 3 , R 6 , R 8 , R 9 , A, X 1 , X 2 , and X 3 of general formula (I), and the various aspects and instances thereof, are each selected independently from each other, with the proviso that at least one of R , R , R , R , R , and R is not H. A twentieth embodiment relates to a compound selected from the group

A first aspect of the twentieth embodiment relates to methods of inducing an immune response in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound according to the twentieth embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A second aspect of the twentieth embodiment relates to methods of inducing an immune response in a patient in need of therapy, comprising administering a therapeutically effective amount of a composition comprising a compound according to the twentieth embodiment above or a pharmaceutically acceptable salt thereof to the patient. A third aspect of the twentieth embodiment relates to methods of inducing STING-dependent type I interferon production in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound according to the twentieth embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A fourth aspect of the twentieth embodiment relates to methods of inducing STING-dependent type I interferon production in a patient in need of therapy, comprising administering a therapeutically effective amount of a composition comprising a compound according to the twentieth embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A fifth aspect of the twentieth embodiment relates to methods of inducing STING-dependent cytokine production in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound according to the twentieth embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A sixth aspect of the twentieth embodiment relates to methods of inducing a STING-dependent cytokine production in a patient in need of therapy, comprising administering a therapeutically effective amount of a composition comprising a compound according to the twentieth embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A seventh aspect of the twentieth embodiment relates to methods of treating a cell proliferation disorder in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt thereof to the patient. In instances of this seventh aspect of the twentieth embodiment, the cell proliferation disorder is cancer.

An eighth aspect of the twentieth embodiment relates to methods of treating a cell proliferation disorder in a patient in need of therapy, said method comprising administering a therapeutically effective amount of a composition according to the eleventh aspect described above to the patient. In instances of this eighth aspect of the twentieth embodiment, the cell proliferation disorder is cancer.

A twenty-first embodiment relates to a compound selected from the exemplary species depicted in Examples 1 through 19 shown below.

A first aspect of the twenty -first embodiment relates to methods of inducing an immune response in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound according to the twenty -first embodiment above or a pharmaceutically acceptable salt thereof to the patient. A second aspect of the twenty-first embodiment relates to methods of inducing an immune response in a patient in need of therapy, comprising administering a therapeutically effective amount of a composition comprising a compound according to the twenty-first embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A third aspect of the twenty -first embodiment relates to methods of inducing STING-dependent type I interferon production in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound according to the twenty -first embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A fourth aspect of the twenty-first embodiment relates to methods of inducing STING-dependent type I interferon production in a patient in need of therapy, comprising administering a therapeutically effective amount of a composition comprising a compound according to the twenty -first embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A fifth aspect of the twenty-first embodiment relates to methods of inducing STING-dependent cytokine production in a patient in need of therapy, comprising administering a therapeutically effective amount of a compound according to the twenty-first embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A sixth aspect of the twenty -first embodiment relates to methods of inducing STING-dependent cytokine production in a patient in need of therapy, comprising administering a therapeutically effective amount of a composition comprising a compound according to the twenty-first embodiment above or a pharmaceutically acceptable salt thereof to the patient.

A seventh aspect of the twenty-first embodiment relates to methods of treating a cell proliferation disorder in a patient in need of therapy, comprising administering a

therapeutically effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt thereof to the patient. In instances of this seventh aspect of the twenty-first embodiment, the cell proliferation disorder is cancer.

An eighth aspect of the twenty -first embodiment relates to methods of treating a cell proliferation disorder in a patient in need of therapy, said method comprising administering a therapeutically effective amount of a composition according to the eleventh aspect described above to the patient. In instances of this eighth aspect of the twenty-first embodiment, the cell proliferation disorder is cancer.

Other embodiments of the present disclosure include the following: (a) A pharmaceutical composition comprising an effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

(b) The pharmaceutical composition of (a), further comprising an active agent selected from the group consisting of STING agonist compounds, anti-viral compounds, antigens, adjuvants, CTLA-4 and PD-l pathway antagonists and other immunomodulatory agents, lipids, liposomes, peptides, anti-cancer and chemotherapeutic agents.

(c) A pharmaceutical combination that is (i) a compound of general formula (I), or a pharmaceutically acceptable salt thereof, and (ii) an active agent selected from the group consisting of STING agonist compounds, anti-viral compounds, antigens, adjuvants, CTLA-4 and PD-l pathway antagonists and other immunomodulatory agents, lipids, liposomes, peptides, anti-cancer and chemotherapeutic agents; wherein the compound of general formula (I), or pharmaceutically acceptable salt thereof, and the active agent are each employed in an amount that renders the combination effective for inducing an immune response in a patient.

(d) A method of inducing an immune response in a patient in need of therapy, which comprises administering to the patient a therapeutically effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt thereof.

(e) A method of inducing an immune response in a patient in need of therapy, which comprises administering to the patient a therapeutically effective amount of a composition of (a), a composition of (b), or a combination of (c).

(f) A method of inducing STING-dependent type I interferon production in a patient in need of therapy, which comprises administering to the patient a therapeutically effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt thereof.

(g) A method of inducing STING-dependent type I interferon production in a patient in need of therapy, which comprises administering to the patient a therapeutically effective amount of a composition of (a), a composition of (b), or a combination of (c).

(h) A method of inducing STING-dependent cytokine production in a patient in need of therapy, which comprises administering to the patient a therapeutically effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt thereof.

(i) A method of inducing STING-dependent cytokine production in a patient in need of therapy, which comprises administering to the patient a therapeutically effective amount of a composition of (a), a composition of (b), or a combination of (c). (j) A method of treating a cell proliferation disorder in a patient in need of therapy, said method comprising administering a therapeutically effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt thereof to the patient;

(k) The method of (j), wherein the cell proliferation disorder is cancer.

(l) A method of treating a cell proliferation disorder in a patient in need of therapy, said method comprising administering a therapeutically effective amount of a composition of (a), a composition of (b),or a combination of (c) to the patient.

(m) The method of (1), wherein the cell proliferation disorder is cancer.

The present disclosure also includes a compound of the present disclosure for use (i) in, (ii) as a medicament for, or (iii) in the preparation of a medicament for: (a) inducing an immune response in a patient in need of therapy, or (b) inducing STING-dependent cytokine production in a patient in need of therapy. In these uses, the compounds of the present disclosure can optionally be employed in combination with one or more active agents selected from STING agonist compounds, anti-viral compounds, antigens, adjuvants, CTLA-4 and PD-l pathway antagonists and other immunomodulatory agents, lipids, liposomes, peptides, anti-cancer agents, and chemotherapeutic agents.

Additional embodiments of the disclosure include the pharmaceutical compositions, combinations and methods set forth in (a) through (m) above and the uses set forth in the preceding paragraph, wherein the compound of the present disclosure employed therein is a compound of one of the embodiments, aspects, instances, occurrences, or features of the compounds described above. In all of these embodiments, the compound may optionally be used in the form of a pharmaceutically acceptable salt, as appropriate.

In the embodiments of the compound provided above, it is to be understood that each embodiment may be combined with one or more other embodiments, to the extent that such a combination provides a stable compound and is consistent with the description of the embodiments. It is further to be understood that the embodiments of compositions and methods provided as (a) through (m) above are understood to include all embodiments of the compounds, including such embodiments as result from combinations of embodiments.

The terms“subject” or alternatively“patient” as used herein refers to a mammal that has been the object of treatment, observation, or experiment. The mammal may be male or female. The mammal may be one or more selected from the group consisting of humans, bovine (e.g., cows), porcine (e.g., pigs), ovine (e.g., sheep), capra (e.g., goats), equine (e.g., horses), canine (e.g., domestic dogs), feline (e.g., house cats), Lagomorpha (rabbits), rodents (e.g., rats or mice), Procyon lotor (e.g., raccoons). In particular embodiments, the subject is human.

As used herein, the term“immune response” relates to any one or more of the following: specific immune response, non-specific immune response, both specific and non specific response, innate response, primary immune response, adaptive immunity, secondary immune response, memory immune response, immune cell activation, immune cell proliferation, immune cell differentiation, and cytokine expression. In certain embodiments, a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, is administered in conjunction with one or more additional therapeutic agents including anti-viral compounds, vaccines intended to stimulate an immune response to one or more predetermined antigens, adjuvants, CTLA-4 and PD-l pathway antagonists and other immunomodulatory agents, lipids, liposomes, peptides, anti-cancer agents, and chemotherapeutic agents, etc. In certain

embodiments, a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, is administered in conjunction with one or more additional compositions including anti-viral compounds, vaccines intended to stimulate an immune response to one or more predetermined antigens, adjuvants, CTLA-4 and PD-l pathway antagonists and other immunomodulatory agents, lipids, liposomes, peptides, anti-cancer agents, and chemotherapeutic agents, etc.

Compounds

The term“alkyl” refers to a straight or branched chain, saturated aliphatic hydrocarbon radical having a number of carbon atoms in the specified range. Thus, for example, “Ci- 6 alkyl” (or“C1-C6 alkyl”) refers to any of the hexyl alkyl and pentyl alkyl isomers as well as n-, iso-, sec- and tert- butyl, n- and iso-propyl, ethyl, and methyl. As another example,“C alkyl” refers to n-, iso-, sec- and tert- butyl, n- and isopropyl, ethyl, and methyl.

As used herein, the term“alkenyl” refers to a straight or branched chain, unsaturated aliphatic hydrocarbon radical having a number of carbon atoms in the specified range and including one or more double bonds.

As used herein, the term“alkynyl” refers to a straight or branched chain, unsaturated aliphatic hydrocarbon radical having a number of carbon atoms in the specified range and including one or more triple bonds.

The term“halogen” (or“halo”) refers to fluorine, chlorine, bromine, and iodine (alternatively referred to as fluoro, chloro, bromo, and iodo or F, Cl, Br, and I). The term“haloalkyl” refers to an alkyl group as defined above in which one or more of the hydrogen atoms have been replaced with a halogen. Thus, for example,“Ci_ 6 haloalkyl” (or“Ci-C 6 haloalkyl”) refers to a Ci to C 6 linear or branched alkyl group as defined above with one or more halogen substituents. The term“fluoroalkyl” has an analogous meaning except the halogen substituents are restricted to fluoro. Suitable fluoroalkyls include the series (CH 2 ) O-4 CF 3 (i.e.. trifluoromethyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoro-n-propyl, etc.).

As used herein, the term“haloalkenyl” refers to an alkenyl group as defined above in which one or more of the hydrogen atoms have been replaced with a halogen.

As used herein, the term“haloalkynyl” refers to an alkynyl group as defined above in which one or more of the hydrogen atoms have been replaced with a halogen.

As used herein, the term“alkoxy” as used herein, alone or in combination, includes an alkyl group connected to the oxy connecting atom. The term“alkoxy” also includes alkyl ether groups, where the term“alkyl” is defined above, and“ether” means two alkyl groups with an oxygen atom between them. Examples of suitable alkoxy groups include methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, s-butoxy, t-butoxy, methoxymethane (also referred to as “dimethyl ether”), and methoxy ethane (also referred to as“ethyl methyl ether”).

As used herein, the term“cycloalkyl” refers to a saturated hydrocarbon containing one ring having a specified number of carbon atoms. Examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

As used herein, the term“heterocycle”,“heterocyclyl”, or“heterocyclic”, as used herein, represents a stable 3- to 6-membered monocyclic that is either saturated or unsaturated, and that consists of carbon atoms and from one to two heteroatoms selected from the group consisting of N, O, and S. The heterocyclic ring may be attached at any heteroatom or carbon atom which results in the creation of a stable structure. The term includes heteroaryl moieties. Examples of such heterocyclic elements include, but are not limited to, azepinyl, benzimidazolyl, benzisoxazolyl, benzofurazanyl, benzopyranyl, benzothiopyranyl, benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl, cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl, dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone, l,3-dioxolanyl, furyl,

imidazolidinyl, imidazolinyl, imidazolyl, indolinyl, indolyl, isochromanyl, isoindolinyl, isoquinolinyl, isothiazolidinyl, isothiazolyl, isothiazolidinyl, morpholinyl, naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, oxazolyl, 2-oxopiperazinyl, 2-oxopiperdinyl, 2-oxopyrrolidinyl, piperidyl, piperazinyl, pyridyl, pyrazinyl, pyrazolidinyl, pyrazolyl, pyridazinyl, pyrimidinyl, pyrrolidinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, thiamorpholinyl, thiamorpholinyl sulfoxide, thiazolyl, thiazolinyl, thienofuryl, thienothienyl, triazolyl and thienyl.

As used herein, the term“fused ring” refers to a cyclic group formed by substituents on separate atoms in a straight or branched alkane, or to a cyclic group formed by substituents on separate atoms in another ring.

As used herein, the term“spirocycle” or“spirocyclic ring” refers to a pendant cyclic group formed by substituents on a single atom.

Unless expressly stated to the contrary, all ranges cited herein are inclusive; i.e., the range includes the values for the upper and lower limits of the range as well as all values in between. As an example, temperature ranges, percentages, ranges of equivalents, and the like described herein include the upper and lower limits of the range and any value in the continuum there between. Numerical values provided herein, and the use of the term“about”, may include variations of ± 1%, ± 2%, ±3%, ± 4%, ± 5%, ± 10%, ± 15%, and ± 20% and their numerical equivalents.

As used herein, the term“one or more” item includes a single item selected from the list as well as mixtures of two or more items selected from the list.

In the compounds of general formula (I), and pharmaceutically acceptable salts of the foregoing, the atoms may exhibit their natural isotopic abundances, or 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 disclosure is meant to include all suitable isotopic variations of the the compounds of general formula (I), and pharmaceutically acceptable salts of the foregoing.

For example, different isotopic forms of hydrogen (H) include protium deuterium ( 2 H), and tritium ( 3 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 the compounds of general formula (I), and pharmaceutically acceptable salts of the foregoing, can be prepared without undue experimentation by conventional techniques well 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.

In particular embodiments of the the compounds of general formula (I), and pharmaceutically acceptable salts of the foregoing, the compounds are isotopically enriched with deuterium. In aspects of these embodiments, one or more of R , R , R , R , R , and R may include deuterium.

As shown in the general structural formulas and the structures of specific compounds as provided herein, a straight line at a chiral center includes both (R) and (S) stereoisomers and mixtures thereof. Also, unless otherwise specified (e.g., 100% purified compound), reference to a particular stereochemistry at a position provides a compound having the indicated stereochemistry but does not exclude the presence of stereoisomers having different stereochemistry at the indicated position.

Recitation or depiction of a specific compound in the claims (i.e., a species) without a specific stereoconfiguration designation, or with such a designation for less than all chiral centers, is intended to encompass, for such undesignated chiral centers, the racemate, racemic mixtures, each individual enantiomer, a diastereoisomeric mixture and each individual diastereomer of the compound where such forms are possible due to the presence of one or more asymmetric centers. The separation of a mixture of stereoisomers can be earned out at an intermediate step during the synthesis of a compound of general formula (I), or a

pharmaceutically acceptable salt of the foregoing, or it can be done on a final racemic product. Absolute stereochemistry may be determined by X-ray crystallography of crystalline products or crystalline intermediates, which are derivatized, if necessary , with a reagent containing a stereogenic center of known configuration. Alternatively, absolute stereochemistry may be determined by Vibrational Circular Dichroism (VCD) spectroscopy analysis. The present invention includes all such isomers, as well as salts, solvates (including hydrates), and solvated salts of such racemates, enantiomers, diastereomers, tautomers, and mixtures thereof.

The invention includes all possible enantiomers and diastereomers and mixtures of two or more stereoisomers, for example mixtures of enantiomers and/or diastereomers, in all ratios. Thus, enantiomers are a subject of the invention in enantiomerically pure form, both as levorotatory and as dextrorotatory antipodes, in the form of racemates and in the form of mixtures of the two enantiomers in all ratios. In the case of a cis/trans isomerism, the invention includes both the cis form and the trans form, as well as mixtures of these forms in all ratios.

The preparation of individual stereoisomers can be carried out, if desired, by separation of a mixture by customary methods, for example by chromatography or crystallization, by the use of stereochemically uniform starting materials for the synthesis or by stereoselective synthesis. Optionally a derivatization can be carried out before a separation of stereoisomers. The separation of a mixture of stereoisomers can be carried out at an intermediate step during the synthesis of a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, or it can be done on a final racemic product. Absolute stereochemistry may be determined by X-ray crystallography of crystalline products or crystalline intermediates that are derivatized, if necessary, with a reagent containing a stereogenic center of known configuration. Unless a particular isomer, salt, solvate (including hydrates) or solvated salt of such racemate, enantiomer, or diastereomer is indicated, the present invention includes all such isomers, as well as salts, solvates (including hydrates), and solvated salts of such racemates, enantiomers, diastereomers, and mixtures thereof.

The term“compound” refers to the compound and, in certain embodiments, to the extent they are stable, any hydrate or solvate thereof. A hydrate is the compound complexed with water, and a solvate is the compound complexed with a solvent, which may be an organic solvent or an inorganic solvent.

A“stable” compound is a compound that can be prepared and isolated and whose structure and properties remain or can be caused to remain essentially unchanged for a period of time sufficient to allow use of the compound for the purposes described herein (e.g., therapeutic administration to a subject). The compounds of the present invention are limited to stable compounds embraced by general formula (I), or pharmaceutically acceptable salts thereof.

Salts

As indicated above, the compounds of the present invention can be employed in the form of pharmaceutically acceptable salts. Those skilled in the art will recognize those instances in which the compounds of the invention may form salts. Examples of such compounds are described herein by reference to possible salts. Such reference is for illustration only. Pharmaceutically acceptable salts can be used with compounds for treating patients. Non- pharmaceutical salts may, however, be useful in the preparation of intermediate compounds.

The term“pharmaceutically acceptable salt” refers to a salt (including an inner salt such as a zwitterion) that possesses effectiveness similar to the parent compound and that is not biologically or otherwise undesirable (e.g., is neither toxic nor otherwise deleterious to the recipient thereof). Thus, an embodiment of the invention provides pharmaceutically acceptable salts of the compounds of the invention. The term“salt(s)”, as employed herein, denotes any of the following: acidic salts formed with inorganic and/or organic acids, as well as basic salts formed with inorganic and/or organic bases. Salts of compounds of the invention may be formed by methods known to those of ordinary skill in the art, 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 aqueous medium followed by lyophilization.

Exemplary acid addition salts include acetates, ascorbates, benzoates, benzenesulfonates, bisulfates, borates, butyrates, citrates, camphorates, camphorsulfonates, fumarates, hydrochlorides, hydrobromides, hydroiodides, lactates, maleates, methanesulfonates (“mesylates”), naphthalenesulfonates, nitrates, oxalates, phosphates, propionates, salicylates, succinates, sulfates, tartarates, thiocyanates, toluenesulfonates (also known as tosylates) and the like. Suitable salts include acid addition salts that may, for example, be formed by mixing a solution of a compound with a solution of a pharmaceutically acceptable acid such as hydrochloric acid, sulfuric acid, acetic acid, trifluoroacetic acid, or benzoic acid. Additionally, acids that 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) 33 201-217; 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 thereto.

Exemplary basic salts include 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 dicyclohexylamine, /-butyl amine, choline, and salts with amino acids such as arginine, lysine and the like. Basic nitrogen- containing groups may be quartemized 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. Compounds carrying an acidic moiety can be mixed with suitable pharmaceutically acceptable salts to provide, for example, alkali metal salts (e.g., sodium or potassium salts), alkaline earth metal salts (e.g., calcium or magnesium salts), and salts formed with suitable organic ligands such as quaternary ammonium salts. Also, in the case of an acid (-COOH) or alcohol group being present, pharmaceutically acceptable esters can be employed to modify the solubility or hydrolysis characteristics of the compound. All such acid salts and base salts are intended to be pharmaceutically acceptable salts within the scope of the invention and all acid and base salts are considered equivalent to the free forms of the corresponding compounds for purposes of the invention.

In addition, when a compound of the invention contains both a basic moiety, such as, but not limited to an aliphatic primary, secondary, tertiary or cyclic amine, an aromatic or heteroaryl amine, pyridine or imidazole, and an acidic moiety, such as, but not limited to tetrazole or carboxylic acid, zwitterions (“inner salts”) may be formed and are included within the terms“salt(s)” as used herein. It is understood that certain compounds of the invention may exist in zwitterionic form, having both anionic and cationic centers within the same compound and a net neutral charge. Such zwitterions are included within the invention.

Methods of Preparing Compounds

Several methods for preparing the compounds of general formula (I), and pharmaceutically acceptable salts of the foregoing, are described in the following Schemes and Examples. Starting materials and intermediates are purchased from commercial sources, made from known procedures, or are otherwise illustrated. In some cases the order of carrying out the steps of the reaction schemes may be varied to facilitate the reaction or to avoid unwanted reaction products.

In the following Methods and Schemes, LG represents a leaving group, which may be a halide or triflate group. The variables A, R 1 , R 2 , R 3 , R 6 , R 8 , X 1 , X 2 , and X 3 have the same meaning as provided above.

Method 1

Benzo[b]thiophene-2-carboxylic acids or aza-benzo[b]thiophene-2-carboxylic acids, and pharmaceutically acceptable salts thereof, are typically prepared from ortho- halo benzaldehydes 1A as shown in Scheme 1. The sequence starts with treatment with an alpha- thioacetic acid ester under basic conditions. The ester in the resulting compound 1B is cleaved to the carboxylic acid under either acidic or basic conditions to provide the desired substituted benzo[b]thiophene-2-carboxylic acid or aza-benzo[b]thiophene-2-carboxylic acid 1C. SCHEME 1

Method 2

Benzothiazole-2-carboxylic acids or aza-benzothiazole-2-carboxylic acids, and pharmaceutically acceptable salts thereof, can be prepared from substituted aminoarenes 2A as shown in Scheme 2. The sequence starts with acylation with a 2-chloro-2-oxoacetate ester under basic conditions. Reaction of 2B with Lawesson’s reagent affords the thioamide 2C, which in turn is cyclized by reaction with potassium ferri cyanide to afford the desired substituted benzothiazole-2-carboxylic acid or aza-benzothiazole-2-carboxylic acid 2D.

SCHEME 2

Method 3

Another method for the preparation of benzo[b]thiophene-2-carboxylic acids, aza- benzo[b]thiophene-2-carboxylic acids, benzothiazole-2-carboxylic acids, or aza-benzothiazole-2- carboxylic acids, and pharmaceutically acceptable salts thereof, is detailed in Scheme 3. The sequence starts with the appropriate [5.6] heterobicycle 3A unsubstituted at the 2 position.

Treatment with «-butyllithium or LDA, followed by treatment with a cyclic anhydride affords the desired product 3B. SCHEME 3

Method 4

Another method for the preparation of benzo[b]thiophene-2-carboxylic acids, aza- benzo[b]thiophene-2-carboxylic acids, benzothiazole-2-carboxylic acids, or aza-benzothiazole-2- carboxylic acids, and pharmaceutically acceptable salts thereof, is detailed in Scheme 4. The sequence starts with the appropriate [5.6] heterobicycle-2-carboxylic acid 4A, which is reacted with a metal 3-alkoxy-3-oxopropanoate to afford the ieto-ketoester 4B. Alkylation with an «// /?«-haloester affords substitution at the 2-position of the alkyl side chain 4C. Both esters are hydrolyzed under acidic, basic, or a combination of acidic and basic conditions to afford the desired product 4D.

SCHEME 4

Method 5

Another method for the preparation of benzo[b]thiophene-2-carboxylic acids, aza-benzo[b]thiophene-2-carboxylic acids, benzothiazole-2-carboxylic acids, or aza- benzothiazole-2-carboxylic acids, and pharmaceutically acceptable salts thereof, is detailed in Scheme 5. The sequence starts with the appropriate [5.6] heterobicycle-2-carboxylic acid 5A which is converted to the acyl chloride 5B by treatment with either oxalyl chloride or phosphorus(V) oxychloride. The acid chloride 5B is reacted with an alkyl zinc reagent, typically containing an ester, using a transition metal such as copper or palladium to afford 4-ketoester 5C. The ester is cleaved by reaction with either acid or base to afford the desired product 5D.

SCHEME 5

Methods of Use

Compounds described herein having therapeutic applications, such as the compounds of general formula (I), the compounds of the Examples 1 through 19, and pharmaceutically acceptable salts of the foregoing, may be administered to a patient for the purpose of inducing an immune response, inducing STING-dependent cytokine production and/or inducing anti-tumor activity. The term“administration” and variants thereof (e.g., “administering” a compound) means providing the compound to the individual in need of treatment. When a compound is provided in combination with one or more additional active agents (e.g., antiviral agents useful for treating HCV infection or anti -tumor agents for treating cancers),“administration” and its variants are each understood to include concurrent and sequential provision of the compound or salt and other agents.

The compounds disclosed herein may be STING agonists. These compounds are potentially useful in treating diseases or disorders including, but not limited to, cell proliferation disorders. Cell-proliferation disorders include, but are not limited to, cancers, benign

papillomatosis, gestational trophoblastic diseases, and benign neoplastic diseases, such as skin papilloma (warts) and genital papilloma.

In specific embodiments, the disease or disorder to be treated is a cell proliferation disorder. In certain embodiments, the cell proliferation disorder is cancer. In particular embodiments, the cancer is selected from brain and spinal cancers, cancers of the head and neck, leukemia and cancers of the blood, skin cancers, cancers of the reproductive system, cancers of the gastrointestinal system, liver and bile duct cancers, kidney and bladder cancers, bone cancers, lung cancers, malignant mesothelioma, sarcomas, lymphomas, glandular cancers, thyroid cancers, heart tumors, germ cell tumors, malignant neuroendocrine (carcinoid) tumors, midline tract cancers, and cancers of unknown primary (i.e., cancers in which a metastasized cancer is found but the original cancer site is not known). In particular embodiments, the cancer is present in an adult patient; in additional embodiments, the cancer is present in a pediatric patient. In particular embodiments, the cancer is AIDS -related.

In specific embodiments, the cancer is selected from brain and spinal cancers. In particular embodiments, the cancer is selected from the group consisting of anaplastic astrocytomas, glioblastomas, astrocytomas, and estheosioneuroblastomas (also known as olfactory blastomas). In particular embodiments, the brain cancer is selected from the group consisting of astrocytic tumor ( e.g ., pilocytic astrocytoma, subependymal giant-cell astrocytoma, diffuse astrocytoma, pleomorphic xanthoastrocytoma, anaplastic astrocytoma, astrocytoma, giant cell glioblastoma, glioblastoma, secondary glioblastoma, primary adult glioblastoma, and primary pediatric glioblastoma), oligodendroglial tumor (e.g., oligodendroglioma, and anaplastic oligodendroglioma), oligoastrocytic tumor (e.g., oligoastrocytoma, and anaplastic

oligoastrocytoma), ependymoma (e.g., myxopapillary ependymoma, and anaplastic

ependymoma); medulloblastoma, primitive neuroectodermal tumor, schwannoma, meningioma, atypical meningioma, anaplastic meningioma, pituitary adenoma, brain stem glioma, cerebellar astrocytoma, cerebral astorcytoma/malignant glioma, visual pathway and hypothalmic glioma, and primary central nervous system lymphoma. In specific instances of these embodiments, the brain cancer is selected from the group consisting of glioma, glioblastoma multiforme, paraganglioma, and suprantentorial primordial neuroectodermal tumors (sPNET).

In specific embodiments, the cancer is selected from cancers of the head and neck, including nasopharyngeal cancers, nasal cavity and paranasal sinus cancers,

hypopharyngeal cancers, oral cavity cancers (e.g., squamous cell carcinomas, lymphomas, and sarcomas), lip cancers, oropharyngeal cancers, salivary gland tumors, cancers of the larynx (e.g., laryngeal squamous cell carcinomas, rhabdomyosarcomas), and cancers of the eye or ocular cancers. In particular embodiments, the ocular cancer is selected from the group consisting of intraocular melanoma and retinoblastoma.

In specific embodiments, the cancer is selected from leukemia and cancers of the blood. In particular embodiments, the cancer is selected from the group consisting of myeloproliferative neoplasms, myelodysplastic syndromes, myelodysplastic/myeloproliferative neoplasms, acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), chronic myelogenous leukemia (CML), myeloproliferative neoplasm (MPN), post-MPN AML, post- MDS AML, del(5q)-associated high risk MDS or AML, blast-phase chronic myelogenous leukemia, angioimmunoblastic lymphoma, acute lymphoblastic leukemia, Langerans cell histiocytosis, hairy cell leukemia, and plasma cell neoplasms including plasmacytomas and multiple myelomas. Leukemias referenced herein may be acute or chronic.

In specific embodiments, the cancer is selected from skin cancers. In particular embodiments, the skin cancer is selected from the group consisting of melanoma, squamous cell cancers, and basal cell cancers.

In specific embodiments, the cancer is selected from cancers of the reproductive system. In particular embodiments, the cancer is selected from the group consisting of breast cancers, cervical cancers, vaginal cancers, ovarian cancers, prostate cancers, penile cancers, and testicular cancers. In specific instances of these embodiments, the cancer is a breast cancer selected from the group consisting of ductal carcinomas and phyllodes tumors. In specific instances of these embodiments, the breast cancer may be male breast cancer or female breast cancer. In specific instances of these embodiments, the cancer is a cervical cancer selected from the group consisting of squamous cell carcinomas and adenocarcinomas. In specific instances of these embodiments, the cancer is an ovarian cancer selected from the group consisting of epithelial cancers.

In specific embodiments, the cancer is selected from cancers of the gastrointestinal system. In particular embodiments, the cancer is selected from the group consisting of esophageal cancers, gastric cancers (also known as stomach cancers),

gastrointestinal carcinoid tumors, pancreatic cancers, gallbladder cancers, colorectal cancers, and anal cancer. In instances of these embodiments, the cancer is selected from the group consisting of esophageal squamous cell carcinomas, esophageal adenocarcinomas, gastric

adenocarcinomas, gastrointestinal carcinoid tumors, gastrointestinal stromal tumors, gastric lymphomas, gastrointestinal lymphomas, solid pseudopapillary tumors of the pancreas, pancreatoblastoma, islet cell tumors, pancreatic carcinomas including acinar cell carcinomas and ductal adenocarcinomas, gallbladder adenocarcinomas, colorectal adenocarcinomas, and anal squamous cell carcinomas.

In specific embodiments, the cancer is selected from liver and bile duct cancers.

In particular embodiments, the cancer is liver cancer (also known as hepatocellular carcinoma). In particular embodiments, the cancer is bile duct cancer (also known as cholangiocarcinoma); in instances of these embodiments, the bile duct cancer is selected from the group consisting of intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma.

In specific embodiments, the cancer is selected from kidney and bladder cancers. In particular embodiments, the cancer is a kidney cancer selected from the group consisting of renal cell cancer, Wilms tumors, and transitional cell cancers. In particular embodiments, the cancer is a bladder cancer selected from the group consisting of urethelial carcinoma (a transitional cell carcinoma), squamous cell carcinomas, and adenocarcinomas.

In specific embodiments, the cancer is selected from bone cancers. In particular embodiments, the bone cancer is selected from the group consisting of osteosarcoma, malignant fibrous histiocytoma of bone, Ewing sarcoma, chordoma (cancer of the bone along the spine).

In specific embodiments, the cancer is selected from lung cancers. In particular embodiments, the lung cancer is selected from the group consisting of non-small cell lung cancer, small cell lung cancers, bronchial tumors, and pleuropulmonary blastomas.

In specific embodiments, the cancer is selected from malignant mesothelioma. In particular embodiments, the cancer is selected from the group consisting of epithelial mesothelioma and sarcomatoids.

In specific embodiments, the cancer is selected from sarcomas. In particular embodiments, the sarcoma is selected from the group consisting of central chondrosarcoma, central and periosteal chondroma, fibrosarcoma, clear cell sarcoma of tendon sheaths, and Kaposi's sarcoma.

In specific embodiments, the cancer is selected from lymphomas. In particular embodiments, the cancer is selected from the group consisting of Hodgkin lymphoma (e.g., Reed-Stemberg cells), non-Hodgkin lymphoma (e.g., diffuse large B-cell lymphoma, follicular lymphoma, mycosis fungoides, Sezary syndrome, primary central nervous system lymphoma), cutaneous T-cell lymphomas, primary central nervous system lymphomas.

In specific embodiments, the cancer is selected from glandular cancers. In particular embodiments, the cancer is selected from the group consisting of adrenocortical cancer (also known as adrenocortical carcinoma or adrenal cortical carcinoma), pheochromocytomas, paragangliomas, pituitary tumors, thymoma, and thymic carcinomas.

In specific embodiments, the cancer is selected from thyroid cancers. In particular embodiments, the thyroid cancer is selected from the group consisting of medullary thyroid carcinomas, papillary thyroid carcinomas, and follicular thyroid carcinomas. In specific embodiments, the cancer is selected from germ cell tumors. In particular embodiments, the cancer is selected from the group consisting of malignant extracranial germ cell tumors and malignant extragonadal germ cell tumors. In specific instances of these embodiments, the malignant extragonadal germ cell tumors are selected from the group consisting of nonseminomas and seminomas.

In specific embodiments, the cancer is selected from heart tumors. In particular embodiments, the heart tumor is selected from the group consisting of malignant teratoma, lymphoma, rhabdomyosacroma, angiosarcoma, chondrosarcoma, infantile fibrosarcoma, and synovial sarcoma.

In specific embodiments, the cell-proliferation disorder is selected from benign papillomatosis, benign neoplastic diseases and gestational trophoblastic diseases. In particular embodiments, the benign neoplastic disease is selected from skin papilloma (warts) and genital papilloma. In particular embodiments, the gestational trophoblastic disease is selected from the group consisting of hydati diform moles, and gestational trophoblastic neoplasia (e.g., invasive moles, choriocarcinomas, placental-site trophoblastic tumors, and epithelioid trophoblastic tumors).

As used herein, the terms“treatment” and“treating” refer to all processes in which there may be a slowing, interrupting, arresting, controlling, or stopping of the progression of a disease or disorder described herein. The terms do not necessarily indicate a total elimination of all disease or disorder symptoms.

The terms“administration of’ and or“administering” a compound should be understood to include providing a compound described herein, or a pharmaceutically acceptable salt thereof, and compositions of the foregoing to a subject.

The amount of a compound administered to a subject is an amount sufficient to induce an immune response and/or to induce STING-dependent type I interferon production in the subject. In an embodiment, the amount of a compound can be an“effective amount” or “therapeutically effective amount,” such that the subject compound is administered in an amount that will elicit, respectively, a biological or medical (i.e., intended to treat) response of a tissue, system, animal, or human that is being sought by a researcher, veterinarian, medical doctor, or other clinician. An effective amount does not necessarily include considerations of toxicity and safety related to the administration of a compound.

An effective amount of a compound will vary with the particular compound chosen (e.g., considering the potency, efficacy, and/or half-life of the compound); the route of administration chosen; the condition being treated; the severity of the condition being treated; the age, size, weight, and physical condition of the subject being treated; the medical history of the subject being treated; the duration of the treatment; the nature of a concurrent therapy; the desired therapeutic effect; and like factors and can be routinely determined by the skilled artisan.

The compounds disclosed herein may be administered by any suitable route including oral and parenteral administration. Parenteral administration is typically by injection or infusion and includes intravenous, intramuscular, and subcutaneous injection or infusion.

The compounds disclosed herein may be administered once or according to a dosing regimen where a number of doses are administered at varying intervals of time for a given period of time. For example, doses may be administered one, two, three, or four times per day. Doses may be administered until the desired therapeutic effect is achieved or indefinitely to maintain the desired therapeutic effect. Suitable dosing regimens for a compound disclosed herein depend on the pharmacokinetic properties of that compound, such as absorption, distribution and half-life, that can be determined by a skilled artisan. In addition, suitable dosing regimens, including the duration such regimens are administered, for a compound disclosed herein depend on the disease or condition being treated, the severity of the disease or condition, the age and physical condition of the subject being treated, the medical history of the subject being treated, the nature of concurrent therapy, the desired therapeutic effect, and like factors within the knowledge and expertise of the skilled artisan. It will be further understood by such skilled artisans that suitable dosing regimens may require adjustment given an individual subject's response to the dosing regimen or over time as the individual subject needs change. Typical daily dosages may vary depending upon the particular route of administration chosen.

One embodiment of the present disclosure provides for a method of treating a cell proliferation disorder comprising administration of a therapeutically effective amount of a compound of general formula (I), and pharmaceutically acceptable salts of the foregoing, to a subject in need of treatment thereof. In embodiments, the disease or disorder to be treated is a cell proliferation disorder. In aspects of these embodiments, the cell proliferation disorder is cancer. In further aspects of these embodiments, the cancer is selected from brain and spinal cancers, cancers of the head and neck, leukemia and cancers of the blood, skin cancers, cancers of the reproductive system, cancers of the gastrointestinal system, liver and bile duct cancers, kidney and bladder cancers, bone cancers, lung cancers, malignant mesothelioma, sarcomas, lymphomas, glandular cancers, thyroid cancers, heart tumors, germ cell tumors, malignant neuroendocrine (carcinoid) tumors, midline tract cancers, and cancers of unknown primary. In one embodiment, disclosed herein is the use of a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, in a therapy. The compound may be useful in a method of inducing an immune response and/or inducing STING-dependent type I interferon production in a subject, such as a mammal in need of such inhibition, comprising administering an effective amount of the compound to the subject.

In one embodiment, disclosed herein is a pharmaceutical composition comprising at least one compound of general formula (I), or at least one pharmaceutically acceptable salt of the foregoing, for use in potential treatment to induce an immune response and/or to induce STING-dependent type I interferon production.

One embodiment disclosed herein is the use of a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, in the manufacture of a medicament to induce an immune response and/or to induce STING-dependent type I interferon production. In embodiments, the disease or disorder to be treated is a cell proliferation disorder. In aspects of these embodiments, the cell proliferation disorder is cancer. In further aspects of these embodiments, the cancer is selected from brain and spinal cancers, cancers of the head and neck, leukemia and cancers of the blood, skin cancers, cancers of the reproductive system, cancers of the gastrointestinal system, liver and bile duct cancers, kidney and bladder cancers, bone cancers, lung cancers, malignant mesothelioma, sarcomas, lymphomas, glandular cancers, thyroid cancers, heart tumors, germ cell tumors, malignant neuroendocrine (carcinoid) tumors, midline tract cancers, and cancers of unknown primary.

Compositions

The term“composition” as used herein is intended to encompass a dosage form comprising a specified compound in a specified amount, as well as any dosage form that results, directly or indirectly, from combination of a specified compound in a specified amount. Such term is intended to encompass a dosage form comprising a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, and one or more pharmaceutically acceptable carriers or excipients. Accordingly, the compositions of the present disclosure encompass any composition made by admixing a compound of the present disclosure and one or more pharmaceutically acceptable carrier or excipients. By“pharmaceutically acceptable”, it is meant the carriers or excipients are compatible with the compound disclosed herein and with other ingredients of the composition. For the purpose of inducing an immune response and/or inducing STING- dependent type I interferon production, the compounds of general formula (I), or

pharmaceutically acceptable salts of the foregoing, can be administered by means that produces contact of the active agent with the agent’s site of action. The compounds can be administered by conventional means available for use in conjunction with pharmaceuticals, either as individual therapeutic agents or in a combination of therapeutic agents. The compounds can be administered alone, but typically are administered with a pharmaceutical carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice.

In one embodiment, disclosed herein is a composition comprising a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, and one or more pharmaceutically acceptable carriers or excipients. The composition may be prepared and packaged in bulk form in which a therapeutically effective amount of a compound of the disclosure can be extracted and then given to a subject, such as with powders or syrups.

Alternatively, the composition may be prepared and packaged in unit dosage form in which each physically discrete unit contains a therapeutically effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing.

The compounds disclosed herein and a pharmaceutically acceptable carrier or excipient(s) will typically be formulated into a dosage form adapted for administration to a subject by a desired route of administration. For example, dosage forms include those adapted for (1) oral administration, such as tablets, capsules, caplets, pills, troches, powders, syrups, elixirs, suspensions, solutions, emulsions, sachets, and cachets; and (2) parenteral administration, such as sterile solutions, suspensions, and powders for reconstitution. Suitable pharmaceutically acceptable carriers or excipients will vary depending upon the particular dosage form chosen. In addition, suitable pharmaceutically acceptable carriers or excipients may be chosen for a particular function that they may serve in the composition. For example, certain

pharmaceutically acceptable carriers or excipients may be chosen for their ability to facilitate the production of uniform dosage forms. Certain pharmaceutically acceptable carriers or excipients may be chosen for their ability to facilitate the production of stable dosage forms. Certain pharmaceutically acceptable carriers or excipients may be chosen for their ability to facilitate the carrying or transporting of a compound disclosed herein, once administered to the subject, from one organ or portion of the body to another organ or another portion of the body. Certain pharmaceutically acceptable carriers or excipients may be chosen for their ability to enhance patient compliance. Suitable pharmaceutically acceptable excipients include the following types of excipients: diluents, lubricants, binders, disintegrants, fillers, glidants, granulating agents, coating agents, wetting agents, solvents, co-solvents, suspending agents, emulsifiers, sweeteners, flavoring agents, flavor masking agents, coloring agents, anti-caking agents, hemectants, chelating agents, plasticizers, viscosity increasing agents, antioxidants, preservatives, stabilizers, surfactants, and buffering agents.

A skilled artisan possesses the knowledge and skill in the art to select suitable pharmaceutically acceptable carriers and excipients in appropriate amounts for the use in the compositions of the disclosure. In addition, there are a number of resources available to the skilled artisan, which describe pharmaceutically acceptable carriers and excipients and may be useful in selecting suitable pharmaceutically acceptable carriers and excipients. Examples include REMINGTON'S PHARMACEUTICAL SCIENCES (Mack Publishing Company), THE

HANDBOOK OF PHARMACEUTICAL ADDITIVES (Gower Publishing Limited), and THE HANDBOOK OF PHARMACEUTICAL EXCIPIENTS (the American Pharmaceutical Association and the

Pharmaceutical Press).

The compositions of the disclosure are prepared using techniques and methods known to those skilled in the art. Some methods commonly used in the art are described in REMINGTON'S PHARMACEUTICAL SCIENCES (Mack Publishing Company).

In one embodiment, the disclosure is directed to a solid oral dosage form such as a tablet or capsule comprising a therapeutically effective amount of a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, and a diluent or filler.

Suitable diluents and fillers include lactose, sucrose, dextrose, mannitol, sorbitol, starch (e.g., com starch, potato starch, and pre-gelatinized starch), cellulose and its derivatives, (e.g., microcrystalline cellulose), calcium sulfate, and dibasic calcium phosphate. The solid oral dosage form may further comprise a binder. Suitable binders include starch (e.g., com starch, potato starch, and pre-gelatinized starch) gelatin, acacia, sodium alginate, alginic acid, tragacanth, guar gum, povidone, and cellulose and its derivatives (e.g., microcrystalline cellulose). The solid oral dosage form may further comprise a disintegrant. Suitable disintegrants include crospovidone, sodium starch glycolate, croscarmelose, alginic acid, and sodium carboxymethyl cellulose. The solid oral dosage form may further comprise a lubricant. Suitable lubricants include stearic acid, magnesium stearate, calcium stearate, and talc. Where appropriate, dosage unit formulations for oral administration can be microencapsulated. The composition can also be prepared to prolong or sustain the release as, for example, by coating or embedding particulate material in polymers, wax, or the like.

The compounds disclosed herein may also be coupled with soluble polymers as targetable drug carriers. Such polymers can include polyvinylpyrrolidone, pyrancopolymer, polyhydroxypropylmethacrylamidephenol, polyhydroxy ethylaspartamidephenol, or

polyethyleneoxidepolylysine substituted with palmitoyl residues. Furthermore, the compounds of the disclosure may be coupled to a class of biodegradable polymers useful in achieving controlled release of a drug, for example polylactic acid, polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydropyrans, polycyanacrylates, and cross- linked or amphipathic block copolymers of hydrogels.

In one embodiment, the disclosure is directed to a liquid oral dosage form. Oral liquids such as solutions, syrups, and elixirs can be prepared in dosage unit form so that a given quantity contains a predetermined amount of a compound or a pharmaceutically acceptable salt thereof disclosed herein. Syrups can be prepared by dissolving the compound of the disclosure in a suitably flavored aqueous solution; elixirs are prepared through the use of a non-toxic alcoholic vehicle. Suspensions can be formulated by dispersing a compound disclosed herein in a non-toxic vehicle. Solubilizers and emulsifiers such as ethoxylated isostearyl alcohols and polyoxy ethylene sorbitol ethers, preservatives, flavor additives such as peppermint oil, or other natural sweeteners or saccharin or other artificial sweeteners and the like can also be added.

In one embodiment, the disclosure is directed to compositions for parenteral administration. Compositions adapted for parenteral administration include aqueous and non- aqueous sterile injection solutions that may contain anti-oxidants, buffers, bacteriostats, and solutes that render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions that may include suspending agents and thickening agents. The compositions may be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition, requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules, and tablets.

Combinations The compounds of general formula (I), and/or pharmaceutically acceptable salts of the foregoing, may be administered in combination with one or more additional active agents. In embodiments, one or more compounds of general formula (I), or one or more

pharmaceutically acceptable salts of the foregoing, and the one or more additional active agents may be co-administered. The additional active agent(s) may be administered in a single dosage form with the compound of general formula (I), or pharmaceutically acceptable salt of the foregoing, or the additional active agent(s) may be administered in separate dosage form(s) from the dosage form containing the compound of general formula (I), or pharmaceutically acceptable salt of the foregoing.

The additional active agent(s) may be provided as a pharmaceutically acceptable salt, where appropriate.

The additional active agent(s) may be one or more agents selected from the group consisting of STING agonist compounds, anti-viral compounds, antigens, adjuvants, anti-cancer agents, CTLA-4, LAG-3 and PD-l pathway antagonists, lipids, liposomes, peptides, cytotoxic agents, chemotherapeutic agents, immunomodulatory cell lines, checkpoint inhibitors, vascular endothelial growth factor (VEGF) receptor inhibitors, topoisomerase II inhibitors, smoothen inhibitors, alkylating agents, anti-tumor antibiotics, anti-metabolites, retinoids, and

immunomodulatory agents including but not limited to anti-cancer vaccines. It will be understood that such additional active agent(s) may be provided as a pharmaceutically acceptable salt. It will be understood the descriptions of the above additional active agents may be overlapping. It will also be understood that the treatment combinations are subject to optimization, and it is understood that the best combination to use of the compounds of general formula (I), or pharmaceutically acceptable salts of the foregoing, and one or more additional active agents will be determined based on the individual patient needs.

A compound disclosed herein may be used in combination with one or more other active agents, including but not limited to, other anti-cancer agents that are used in the prevention, treatment, control, amelioration, or reduction of risk of a particular disease or condition (e.g., cell proliferation disorders). In one embodiment, a compound disclosed herein is combined with one or more other anti-cancer agents for use in the prevention, treatment, control amelioration, or reduction of risk of a particular disease or condition for which the compounds disclosed herein are useful. Such other active agents may be administered, by a route and in an amount commonly used therefor, contemporaneously or sequentially with a compound of the present disclosure. When a compound disclosed herein is used contemporaneously with one or more other active agents, a composition containing such other active agents in addition to the compound disclosed herein is contemplated. Accordingly, the compositions of the present disclosure include those that also contain one or more other active ingredients, in addition to a compound disclosed herein. A compound disclosed herein may be administered either simultaneously with, or before or after, one or more other active agent(s). A compound disclosed herein may be administered separately, by the same or different route of

administration, or together in the same pharmaceutical composition as the other agent(s).

Products provided as combinations may include a composition comprising a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, and one or more other active agent(s) together in the same pharmaceutical composition, or may include a composition comprising a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, and a composition comprising one or more other active agent(s) in separate form, e.g. in the form of a kit or in any form designed to enable separate administration either concurrently or on separate dosing schedules.

The weight ratio of a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, to a second active agent may be varied and will depend upon the therapeutically effective dose of each agent. Generally, a therapeutically effective dose of each will be used. Combinations of a compound disclosed herein and other active agents will generally also be within the aforementioned range, but in each case, a therapeutically effective dose of each active agent should be used. In such combinations, the compound disclosed herein and other active agents may be administered separately or in conjunction. In addition, the administration of one element may be prior to, concurrent to, or subsequent to the administration of other agent(s).

In one embodiment, this disclosure provides a composition comprising a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, and at least one other active agent as a combined preparation for simultaneous, separate or sequential use in therapy. In one embodiment, the therapy is the treatment of a cell proliferation disorder, such as cancer.

In one embodiment, the disclosure provides a kit comprising two or more separate pharmaceutical compositions, at least one of which contains a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing. In one embodiment, the kit comprises means for separately retaining said compositions, such as a container, divided bottle, or divided foil packet. An example of such a kit is a blister pack, as typically used for the packaging of tablets, capsules, and the like.

A kit of this disclosure may be used for administration of different dosage forms, for example, oral and parenteral, for administration of the separate compositions at different dosage intervals, or for titration of the separate compositions against one another. To assist with compliance, a kit of the disclosure typically comprises directions for administration.

Disclosed herein is a use of a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, for treating a cell proliferation disorder, where the medicament is prepared for administration with another active agent. The disclosure also provides the use of another active agent for treating a cell proliferation disorder, where the medicament is administered with a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing.

The disclosure also provides the use of a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing, for treating a cell proliferation disorder, where the patient has previously (e.g., within 24 hours) been treated with another active agent. The disclosure also provides the use of another active agent for treating a cell proliferation disorder, where the patient has previously (e.g., within 24 hours) been treated with a compound of general formula (I), or a pharmaceutically acceptable salt of the foregoing. The second agent may be administered a week, several weeks, a month, or several months after the administration of a compound disclosed herein.

STING agonist compounds that may be used in combination with the compounds of general formula (I), or pharmaceutically acceptable salts of the foregoing, disclosed herein include but are not limited to cyclic di-nucleotide compounds, such as those disclosed, for example, in International Patent Application Publication Nos. WO2014093936,

WO2014189805, WO2014189806, WO2015185565, W02016120305, WO2016096174, WO2016096577, WO2017027645, WO2017027646, WO2017075477, WO2017093933, and WO2018009466.

Anti-viral compounds that may be used in combination with the compounds of general formula (I), or pharmaceutically acceptable salts of the foregoing, disclosed herein include hepatitis B virus (HBV) inhibitors, hepatitis C virus (HCV) protease inhibitors, HCV polymerase inhibitors, HCV NS4A inhibitors, HCV NS5A inhibitors, HCV NS5b inhibitors, and human immunodeficiency virus (HIV) inhibitors. Such anti-viral compounds may be provided as a pharmaceutically acceptable salt, where appropriate. Antigens and adjuvants that may be used in combination with the compounds of general formula (I), or the pharmaceutically acceptable salts of the foregoing, include B7 costimulatory molecule, interleukin-2, interferon-y, GM-CSF, CTLA-4 antagonists, OX-40/0X- 40 ligand, CD40/CD40 ligand, sargramostim, levamisol, vaccinia virus, Bacille Calmette-Guerin (BCG), liposomes, alum, Freund's complete or incomplete adjuvant, detoxified endotoxins, mineral oils, surface active substances such as lipolecithin, pluronic polyols, polyanions, peptides, and oil or hydrocarbon emulsions. Adjuvants, such as aluminum hydroxide or aluminum phosphate, can be added to increase the ability of the vaccine to trigger, enhance, or prolong an immune response. Additional materials, such as cytokines, chemokines, and bacterial nucleic acid sequences, like CpG, a toll-like receptor (TLR) 9 agonist as well as additional agonists for TLR 2, TLR 4, TLR 5, TLR 7, TLR 8, TLR9, including lipoprotein, LPS, monophosphoryllipid A, lipoteichoic acid, imiquimod, resiquimod, and in addition retinoic acid- inducible gene I (RIG-I) agonists such as poly I:C, used separately or in combination with the described compositions are also potential adjuvants. Such antigens and anjuvants may be provided as a pharmaceutically acceptable salt, where appropriate.

CLTA-4 and PD-l pathways are important negative regulators of immune response. Activated T-cells up-regulate CTLA-4, which binds on antigen-presenting cells and inhibits T-cell stimulation, IL-2 gene expression, and T-cell proliferation; these anti -tumor effects have been observed in mouse models of colon carcinoma, metastatic prostate cancer, and metastatic melanoma. PD-l binds to active T-cells and suppresses T-cell activation; PD-l antagonists have demonstrated anti -tumor effects as well. CTLA-4 and PD-l pathway antagonists that may be used in combination with the compounds of general formula (la), the compounds of general formula (I), or the pharmaceutically acceptable salts of the foregoing, disclosed herein, include ipilimumab, tremelimumab, nivolumab, pembrolizumab, CT-011, AMP-224, and MDX-1106.

“PD-l antagonist” or“PD-l pathway antagonist” means any chemical compound or biological molecule that blocks binding of PD-L 1 expressed on a cancer cell to PD-l expressed on an immune cell (T-cell, B-cell, or NKT-cell) and preferably also blocks binding of PD-L2 expressed on a cancer cell to the immune-cell expressed PD-L Alternative names or synonyms for PD-l and its ligands include: PDCD1, PD1, CD279, and SLEB2 for PD-l;

PDCD1L1, PDL1, B7H1, B7-4, CD274, and B7-H for PD-L1; and PDCD1L2, PDL2, B7-DC, Btdc, and CD273 for PD-L2. In any of the treatment method, medicaments and uses of the present disclosure in which a human individual is being treated, the PD-l antagonist blocks binding of human PD-L1 to human PD-l, and preferably blocks binding of both human PD-L1 and PD-L2 to human PD-l. Human PD-l amino acid sequences can be found in NCBI Locus No.: NP 005009. Human PD-L1 and PD-L2 amino acid sequences can be found in NCBI Locus No.: NP_054862 and NP_0795l5, respectively.

PD-l antagonists useful in any of the treatment method, medicaments and uses of the present disclosure include a monoclonal antibody (mAh), or antigen binding fragment thereof, which specifically binds to PD-l or PD-L1, and preferably specifically binds to human PD-l or human PD-L1. The mAh may be a human antibody, a humanized antibody, or a chimeric antibody and may include a human constant region. In some embodiments, the human constant region is selected from the group consisting of IgGl, IgG2, IgG3, and IgG4 constant regions, and in preferred embodiments, the human constant region is an IgGl or IgG4 constant region. In some embodiments, the antigen binding fragment is selected from the group consisting of Fab, Fab'-SH, F(ab')2, scFv, and Fv fragments.

Examples of mAbs that bind to human PD-l, and useful in the treatment method, medicaments and uses of the present disclosure, are described in U.S. Patent Nos. US7488802, US7521051, US8008449, US8354509, and US8168757, PCT International Patent Application Publication Nos. W02004/004771, W02004/072286, and W02004/056875, and U.S. Patent Application Publication No. US2011/0271358.

Examples of mAbs that bind to human PD-L1, and useful in the treatment method, medicaments and uses of the present disclosure, are described in PCT International Patent Application Nos. W02013/019906 and W02010/077634 Al and in U.S. Patent No. US8383796. Specific anti-human PD-L1 mAbs useful as the PD-l antagonist in the treatment method, medicaments and uses of the present disclosure include MPDL3280A, BMS-936559, MEDI4736, MSB0010718C, and an antibody that comprises the heavy chain and light chain variable regions of SEQ ID NO:24 and SEQ ID NO:2l, respectively, of W02013/019906.

Other PD-l antagonists useful in any of the treatment method, medicaments, and uses of the present disclosure include an immune-adhesion that specifically binds to PD-l or PD- Ll, and preferably specifically binds to human PD-l or human PD-L1, e.g., a fusion protein containing the extracellular or PD-l binding portion of PD-L1 or PD-L2 fused to a constant region such as an Fc region of an immunoglobulin molecule. Examples of immune-adhesion molecules that specifically bind to PD-l are described in PCT International Patent Application Publication Nos. W02010/027827 and WO2011/066342. Specific fusion proteins useful as the PD-l antagonist in the treatment method, medicaments, and uses of the present disclosure include AMP -224 (also known as B7-DCIg), which is a PD-L2-FC fusion protein and binds to human PD-l.

Examples of cytotoxic agents that may be used in combination with the compounds of general formula (I), or pharmaceutically acceptable salts of the foregoing, include, but are not limited to, arsenic trioxide (sold under the tradename TRISENOX®), asparaginase (also known as L-asparaginase, and Erwinia L-asparaginase, sold under the tradenames ELSPAR® and KlDROLASE®).

Chemotherapeutic agents that may be used in combination with the compounds of general formula (I), or pharmaceutically acceptable salts of the foregoing, disclosed herein include abiraterone acetate, altretamine, anhydrovinblastine, auristatin, bexarotene, bicalutamide, BMS 184476, 2,3,4,5,6-pentafluoro-N-(3-fluoro-4-methoxyphenyl) benzene sulfonamide, bleomycin, N,N-dimethyl-L-valyl-L-valyl-N-methyl-L-valyl-L-prolyl- l-Lproline-t-butylamide, cachectin, cemadotin, chlorambucil, cyclophosphamide, 3',4'-didehydro-4'deoxy-8'-norvin- caleukoblastine, docetaxol, doxetaxel, cyclophosphamide, carboplatin, carmustine, cisplatin, cryptophycin, cyclophosphamide, cytarabine, dacarbazine (DTIC), dactinomycin, daunorubicin, decitabine dolastatin, doxorubicin (adriamycin), etoposide, 5-fluorouracil, finasteride, flutamide, hydroxyurea and hydroxyurea andtaxanes, ifosfamide, liarozole, lonidamine, lomustine (CCNU), MDV3100, mechlorethamine (nitrogen mustard), melphalan, mivobulin isethionate, rhizoxin, sertenef, streptozocin, mitomycin, methotrexate, taxanes, nilutamide, nivolumab, onapristone, paclitaxel, pembrolizumab, prednimustine, procarbazine, RPR109881, stramustine phosphate, tamoxifen, tasonermin, taxol, tretinoin, vinblastine, vincristine, vindesine sulfate, and vinflunine. Such chemotherapeutic agents may be provided as a pharmaceutically acceptable salt, where appropriate.

Examples of vascular endothelial growth factor (VEGF) receptor inhibitors include, but are not limited to, bevacizumab (sold under the trademark AVASTIN), axitinib (described in PCT International Patent Publication No. W001/002369), Brivanib Alaninate ((S)- ((R)-l-(4-(4-Fluoro-2-methyl-lH-indol-5-yloxy)-5-methylpyrro lo[2,l-f|[l,2,4]triazin-6- yloxy)propan-2-yl)2-aminopropanoate, also known as BMS-582664), motesanib (N-(2,3- dihydro-3,3-dimethyl-lH-indol-6-yl)-2-[(4-pyridinylmethyl)am ino]-3-pyridinecarboxamide. and described in PCT International Patent Application Publication No. W002/068470), pasireotide (also known as SO 230, and described in PCT International Patent Publication No.

W002/010192), and sorafenib (sold under the tradename NEXAVAR). Such inhibitors may be provided as a pharmaceutically acceptable salt, where appropriate. Examples of topoisomerase II inhibitors, include but are not limited to, etoposide (also known as VP-16 and Etoposide phosphate, sold under the tradenames TOPOSAR, VEPESID, and ETOPOPHOS), and teniposide (also known as VM-26, sold under the tradename VUMON). Such inhibitors may be provided as a pharmaceutically acceptable salt, where appropriate.

Examples of alkylating agents, include but are not limited to, 5-azacytidine (sold under the trade name VIDAZA), decitabine (sold under the trade name of DECOGEN), temozolomide (sold under the trade names TEMCAD, TEMODAR, and TEMODAL), dactinomycin (also known as actinomycin-D and sold under the tradename COSMEGEN), melphalan (also known as L-PAM, L-sarcolysin, and phenylalanine mustard, sold under the tradename ALKERAN), altretamine (also known as hexamethylmelamine (HMM), sold under the tradename HEXALEN), carmustine (sold under the tradename BCNU), bendamustine (sold under the tradename TREANDA), busulfan (sold under the tradenames BUSULFEX® and

MYLERAN®), carboplatin (sold under the tradename PARAPLATIN®), lomustine (also known as CCNU, sold under the tradename CEENU®), cisplatin (also known as CDDP, sold under the tradenames PLATINOL® and PLATINOL®-AQ), chlorambucil (sold under the tradename

LEUKERAN®), cyclophosphamide (sold under the tradenames CYTOXAN® and NEOSAR®), dacarbazine (also known as DTIC, DIC and imidazole carboxamide, sold under the tradename DTIC-DOME®), altretamine (also known as hexamethylmelamine (HMM) sold under the tradename HEXALEN®), ifosfamide (sold under the tradename IFEX®), procarbazine (sold under the tradename MATULANE®), mechlorethamine (also known as nitrogen mustard, mustine and mechloroethamine hydrochloride, sold under the tradename MUSTARGEN®), streptozocin (sold under the tradename ZANOSAR ® ), thiotepa (also known as thiophosphoamide, TESPA and TSPA, and sold under the tradename THIOPLEX®. Such alkylating agents may be provided as a pharmaceutically acceptable salt, where appropriate.

Examples of anti-tumor antibiotics include, but are not limited to, doxorubicin (sold under the tradenames ADRIAMYCIN® and RUBEX®), bleomycin (sold under the tradename LENOXANE ® ), daunorubicin (also known as dauorubicin hydrochloride, daunomycin, and rubidomycin hydrochloride, sold under the tradename CERUBIDINE®), daunorubicin liposomal (daunorubicin citrate liposome, sold under the tradename DAUNOXOME®), mitoxantrone (also known as DHAD, sold under the tradename NOVANTRONE®), epirubicin (sold under the tradename ELLENCE™), idarubicin (sold under the tradenames IDAMYCIN®, IDAMYCIN PFS ® ), and mitomycin C (sold under the tradename MUTAMYCIN®). Such anti -tumor antibiotics may be provided as a pharmaceutically acceptable salt, where appropriate.

Examples of anti-metabolites include, but are not limited to, claribine (2- chlorodeoxyadenosine, sold under the tradename LEUSTATIN®), 5-fluorouracil (sold under the tradename ADRUCIL®), 6-thioguanine (sold under the tradename PURINETHOL®), pemetrexed (sold under the tradename ALIMTA®), cytarabine (also known as arabinosylcytosine (Ara-C), sold under the tradename CYTOSAR-U®), cytarabine liposomal (also known as Liposomal Ara-C, sold under the tradename DEPOCYT™), decitabine (sold under the tradename DACOGEN®), hydroxyurea and (sold under the tradenames HYDREA®, DROXIA™ and MYLOCEL™), fludarabine (sold under the tradename FLUDARA®), floxuridine (sold under the tradename FUDR ® ), cladribine (also known as 2-chlorodeoxyadenosine (2-CdA) sold under the tradename LEUSTATIN™), methotrexate (also known as amethopterin, methotrexate sodium (MTX), sold under the tradenames RHEUMATREX® and TREXALL™), and pentostatin (sold under the tradename NIPENT®). Such anti-metabolites may be provided as a pharmaceutically acceptable salt, where appropriate.

Examples of retinoids include, but are not limited to, alitretinoin (sold under the tradename PANRETIN®), tretinoin (all-trans retinoic acid, also known as ATRA, sold under the tradename VESANOID®), Isotretinoin (l3-c/s-retinoic acid, sold under the tradenames

ACCUTANE®, AMNESTEEM®, CLARA VIS®, CLARUS®, DECUTAN®, ISOTANE®, IZOTECH®,

ORATANE®, ISOTRET®, and SOTRET®), and bexarotene (sold under the tradename TARGRETIN®). Such compounds may be provided as a pharmaceutically acceptable salt, where appropriate.

Activity: STING Biochemical |3H |cGAMP Competition Assay

The individual compounds described in the Examples herein are defined as STING agonists by (i) binding to the STING protein as evidenced by a reduction in binding of tritiated cGAMP ligand to the STING protein by at least 2014 at 20uM (concentration of compound being tested) in a STING Biochemical [3H]cGAMP Competition Assay, and/or (ii) demonstrating interferon production with a 6% or greater induction of IFN-b secretion at 30uM in the THP1 cell assay (where induction caused by cGAMP at 30uM was set at 100%).

The ability of compounds to bind STING is quantified by the ability to compete with tritiated cGAMP ligand for human STING receptor membrane using a radioactive filter- binding assay. The binding assay employs STING receptor obtained from Hi-Five cell membranes overexpressing full-length HAQ STING prepared in-house and tritiated cGAMP ligand also purified in-house.

The following experimental procedures detail the preparation of specific examples of the instant disclosure. The compounds of the examples are drawn in their neutral forms in the procedures and tables below. In some cases, the compounds were isolated as salts depending on the method used for their final purification and/or intrinsic molecular properties. The examples are for illustrative purposes only and are not intended to limit the scope of the instant disclosure in any way.

EXAMPLES

ABBREVIATIONS

2’, 3’cGAMP, cGAMP 2’, 3’-cyclic guanosine monophosphate-adenosine monophosphate Ac Acetyl, CH 3 C(0)

ACN, MeCN, CH 3 CN Acetonitrile

AcOH, HO Ac Acetic acid

AMP Adenosine monophosphate

aq Aqueous

ATP Adenosine 5’-triphosphate

BIIC Baculovirus Infected Insect Cell

br Broad

Bu Butyl, C4H9

cat Catalog number

CD 3 OD Deuterium-enriched methyl alcohol, deuterium-enriched methanol

CDCl 3 Deuterated trichloromethane

CDI Carbonyl diimidazole

cGAMP Cyclic GMP-AMP synthase

Ci Curie, a non-standard unit of radioactivity; lCi=3.7xl0 10 Bq, where Bq is

Becquerel, the SI unit of radioactivity, equivalent to 1 disintegration per second (dps)

CPhos Pd G4 2-Aminobiphenylpalladium methanesulfonate palladium CPhos

precatalyst (4 th generation precatalyst)

Cy Cyclohexyl d Doublet

DCE 1 ,2-Dichloroethane

DCM, CH2CI2 Dichloromethane

ddd Doublet of doublet of doublet

ddt Doublet of doublet of triplet

DMAP 4-dimethylaminopyridine

DMEA N,N-dimethyl ethyl amine

DMF N,N-dimethylformamide

DMO Dimethyl oxalate

DMSO Dimethylsulfoxide

DMTr 4,4’ -dimethoxy trity 1

DMTrCl 4,4’-dimethoxytrityl chloride

dq Doublet of quartet

EC 50 half maximal effective concentration; concentration of a drug, antibody, or toxicant that induces a response halfway between the baseline and maximum after a specified exposure time

EDC (l-Ethyl-3-(3-dimethylaminopropyl)carbodiimide

eq Equivalents

ES Electron spray

Et Ethyl, CH 3 CH 2

GMP Guanosine 5’-monophosphate

GTP Guanosine 5’-triphosphate

h Hour

HAQ STING Common STING variant containing the three mutations R71H-G230A- R293Q (DNA construct used herein: STING(l-379)R7lH,G230A, H232R,R293 Q-GG-AviT ag-GS -HRV3C-HIS 8/pB AC 1 )

HEPES 2-[4-(2-hy droxy ethyl)piperazin- 1 -yl] ethanesulfonic acid, a zwiiterionic organic chemical buffering agent

hept Heptet

Hex Hexanes

HPLC High performance liquid chromatography

IC 50 half maximal inhibitory concentration; concentration of a drug, antibody, or toxicant required for 50% inhibition of response or binding Inh Inhibition

LCMS Liquid chromatography-mass spectroscopy

LDA Lithium di-isopropyl amide

m Multiplet

M Molar, moles per liter

m/z Mass-to-charge ratio

M+H Protonated mass, mass measurement produced by mass spectrometry mCPBA meto-Chloroperoxybenzoic acid

Me Methyl, CH 3

min Minute(s)

mM Millimole per liter

mmol Millimole

MOI Multiplicity of infection

NBS N-Bromosuccinimide

nm Nanometer

nM Nanomolar

NMO N-Methylmorpholine N-oxide

NMP N-methyl-2-pyrrolidone

Pd(Ph 3 P) 4 Tetrakis(triphenyl phosphine) palladium(O)

Pd 2 (dba) 3 Tris(dibenzylidene acetone) dipalladium(O)

PE Petroleum ether

pfu Plaque-forming unit

prep-HPLC Preparative high performance liquid chromatography

prep-TLC Preparative thin layer liquid chromatography

PSI Pounds per square inch

q Quartet

RPM, rpm Revolutions per minute

RT, rt Room temperature, approximately 25°C

s Singlet

sat Saturated

SFC Supercritical fluid chromatography

t Triplet

TFA Trifluoroacetic acid THF Tetrahydrofuran

TLC Thin layer chromatography

TMS Trimethylsilyl

TR Retention time

TrisCl Tris (hy droxy methy l)aminomethane hy drochloride

v/v Volume/volume

WT STING The wild type (most abundant) variant of STING in humans (DNA construct used herein: STING(l-379)H232R-gg-AviTag-gs-HRV3C- HIS8/pBACl)

X-Phos 2-Dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl

^em Emission wavelength

lec Excitation wavelength

Preparation 1: Magnesium 3-(fe/Z-butoxy)-3-oxopropanoate

C XA 0 A

Magnesium ethanolate (3.57g, 3 l.2mmol) was added to a mixture of 3-(lerl- butoxy)-3-oxopropanoic acid (lO.Og, 62.4mmol) in THF (lOOmL) at 20°C. The reaction mixture was stirred at 20°C for 18 hours under Ar. The reaction mixture was then concentrated under reduced pressure. The residue was dried under reduced pressure to afford magnesium 3 -(tert- butoxy)-3-oxopropanoate. 1H NMR (499 MHz, DMSO-r 6 ) d 2.96 (s, 4H), 1.39 (s, 18H).

Preparation 2: tert- Butyl 3-(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)-3-oxopropanoate

Step 1: 3-Bromo-5, 6-dimethoxypyrazine-2-carbaldehvde

To a solution of 2,2,6,6-tetramethylpiperidine (5. l2mL, 30.lmmol) in THF (40mL) at -78°C was added dropwise a solution of w-BuLi (2.5M in Hex, 1 l.5mL, 28.8mmol). The reaction mixture was stirred for 10 min. at -78°C and then warmed to 0°C and stirred for an additional 20 min. The reaction mixture was then cooled back to -78°C, and a solution of 5- bromo-2,3-dimethoxypyrazine (3.00g, l3.7mmol) in THF (lOmL) was added over a period of 5 min. The reaction mixture was stirred at -78°C for 1 hour and then quenched with DMF (l.06mL, l3.7mmol). The reaction mixture was warmed to 0°C and stirred for an additional 20 min. AcOH (3.0mL) was added at 0°C, and the reaction mixture was warmed to RT and stirred ovenight. The mixture was diluted with EtOAc (300mL) and then washed with H 2 0 (2xl50mL) and brine. The organic layer was separated, dried over Na^SO^ filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford 3-bromo-5,6-dimethoxypyrazine-2-carbaldehyde. LCMS (C-HxBrN 2 0 3 ) (ES, m/z):

247, 249 [M+H] + . X H NMR (500MHz, CDCl 3 ) d 10.19 (s, 1H), 4.17 (s, 3H), 4.14 (s, 3H).

tert- Butyl 2-sulfanylacetate (424pL, 2.92mmol) and DMF (2.9mL) were added to 3-bromo-5,6-dimethoxypyrazine-2-carbaldehyde (650mg, 2.63mmol) at RT. K 2 C0 3 (l090mg, 7.89mmol) was then added portion-wise to the reaction mixture at RT. The reaction mixture was heated to 80°C and stirred overnight. The reaction mixture was then cooled to RT, diluted with Et 2 0, and quenched with H 2 0. The reaction mixture was extracted with Et 2 0, and the combined organics were washed with brine, dried over Na 2 S04, filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to yield / -butyl 2,3-dimethoxythieno[2,3-b]pyrazine-6-carboxylate. LCMS (C^HnN^S) (ES, m/z): 297 [M+H] + . X H NMR (500MHz, DMSO-r¾) d 7.89 (s, 1H), 4.02 (s, 3H), 3.99 (s, 3H), 1.55 (s, 9H).

Step 3: 2, 3-Dimethoxythienof 2, 3-b lpyrazine-6-carboxylic acid

To a stirred solution of tert- butyl 2,3-dimethoxythieno[2,3-b]pyrazine-6- carboxylate (400mg, l.35mmol) in DCM (6.0mL) was added HC1 (4.0M in dioxane, l.7mL, 6.8mmol) at RT. The reaction mixture was stirred overnight at RT, and then diluted by the dropwise addition of Hex (50mL) and stirred for an additional 1 hour at RT. The reaction mixture was filtered, and the collected material were washed with Hex (2x10 mL) and dried under reduced pressure to afford 2,3-dimethoxythieno[2,3-b]pyrazine-6-carboxylic acid. LCMS (C9H9N2O4S) (ES, m/z): 241 [M+H] + . X H NMR (500 MHz, DMSO-A) d 12.71 (br s, 1H), 7.90 (s, 1H), 4.03 (s, 3H), 3.99 (s, 3H).

Step 4: tert -Butyl 3-(2 3-dimethoxythieno[2 3-b lpyrazin-6-yl)-3-oxopropanoate

A mixture of 2,3-dimethoxythieno[2,3-b]pyrazine-6-carboxylic acid (80mg, 0.33mmol) and CDI (324mg, 2.00mmol) in THF (5.5mL) was stirred at RT for 3 hours.

Magnesium bis(3-/er/-butoxy-3-oxopropanoate) (628mg, l.83mmol) was added, and the resulting mixture was stirred overnight at RT. The reaction mixture was concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting (25% EtOH in EtOAc) in Hex) to afford tert- butyl 3-(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)-3- oxopropanoate. LCMS (C I5 H I9 N 2 0 5 S) (ES, m/z): 339 [M+H] + . X H NMR (500 MHz, DMSO-A) d 8.32 (s, 1H), 4.13 (s, 2H), 4.04 (s, 3H), 4.00 (s, 3H), 1.41 (s, 9H).

Preparation 3: 5,6-Dimethoxythieno[3,2-b]pyridine-2-carboxylic acid

K 2 CO 3 (H80mg, 8.56mmol) was added to a mixture of 3-chloro-5,6- dimethoxypicolinaldehyde (575mg, 2.86mmol) and /e/V-butyl 2-sulfanylacetate (0.456mL,

3. l4mmol) in DMF (8.3mL) at RT. The reaction mixture was stirred and heated to 60°C for 3 days. The reaction mixture was cooled to RT, and then diluted with Et 2 0 and H 2 0. The organic layer was separated, washed with brine, dried over Na 2 S04, filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford /er/-butyl 5,6-dimethoxythieno[3,2-b]pyridine-2-carboxylate. ' H NMR (499 MHz, DMSO-i¾) d 7.95 (s, 1H), 7.84 (s, 1H), 3.93 (s, 3H), 3.87 (s, 3H), 1.54 (s, 9H).

Step 2: 5 6-dimethoxythienof 3 2-b lOyridine-2-carboxylic acid

HC1 (4.0M in dioxane, 2. lmL, 8.4mmol) was added to a solution of /er/-butyl 5,6- dimethoxythieno[3,2-b]pyridine-2-carboxylate (493mg, l.67mmol) in DCM (7.4mL) at RT. The reacton mixture was stirred overnight at RT, and then diluted by the dropwise addition of Hex (50mL). The mixture was stirred for 1 hour and filtered. The collected materials were washed with Hex (2xl0mL) and then dried under reduced pressure to afford 5,6-dimethoxythieno[3,2- b]pyridine-2-carboxylic acid. LCMS (C H NO S) (ES, m/z): 240 [M+H] + . *H NMR (499 MHz, DMSO-ri 6 ) d 7.97 (s, 1H), 7.85 (s, 1H), 3.95 (s, 3H), 3.88 (s, 3H).

Preparation 4: tert- Butyl 3-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-3-oxopropanoate

CDI (508mg, 3T3mmol) was added to a mixture of 5,6-dimethoxythieno[3,2- b]pyridine-2-carboxylic acid (500mg, 2.09mmol) in THF (5mL). The reaction mixture was stirred at RT for 3 hours. The reaction mixture was added to a separate flask containing magnesium 3-(/er/-butoxy)-3-oxopropanoate (l220mg, 3.55mmol). The reaction mixture was diluted with additonal THF (4mL) and was stirred overnight at RT. The reaction mixture was then heated to 50°C for 1 hour. The reaction mixture was cooled to RT and diluted with H 2 0 (20mL). Sodium citrate tribasic dihydrate (2g) and EtOAc (50mL) were added. The organic layer was separated, and the aqueous layer was extracted with additional EtOAc. The organic layers were combined, washed with brine, dried over anhydrous Na^SO^ filtered, and concentrated under reduced pressure. The residue was purified via silica gel chromatography (eluting EtOAc in Hex) to afford /e/V-butyl 3-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-3- oxopropanoate. LCMS (C I6 H 20 NO 5 S) (ES, m/z): 338 [M+H] + . 1H NMR (500 MHz, CDCl 3 ) d 7.97 (s, 1H), 7.44 (s, 1H), 4.13 (s, 3H), 3.99 (s, 3H), 3.92 (s, 2H), 1.48 (s, 9H).

Example 1: 4- 2-yl)-4-oxobutanoic acid

LDA (2.0M in THF, 0.6lmL, l.22mmol) was added dropwise to a mixture of 5,6- dimethoxybenzo[d]thiazole (200mg, l.02mmol) in THF (5.0mL) at -78°C under N 2 . The reaction mixture was stirred at -78°C for 1 hour. A mixture of succinic anhydride (l23mg, l.22mmol) in THF (2.0mL) was then added dropwise to the reaction mixture at -78°C. The reaction mixture was warmed to RT and stirred for 2 hours. A solution of sat aq NH 4 Cl (l.OmL) and H 2 0 (5.0mL) were then added to the reaction mixture. The reaction mixture was extracted with EtOAc (3x30mL). The organic layers were combined, washed with brine (20mL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by reverse phase HPLC (eluting ACN in H 2 0 with 0.1% TFA) to afford 4-(5,6-dimethoxybenzo[d] thiazol-2-yl)-4-oxobutanoic acid. LCMS (C I3 H I4 N0 5 S) (ES, m/z): 296 [M+H] + . ' H NMR (400 MHz, DMSO-ri 6 ) d 7.76 (s, 1H), 7.75 (s, 1H), 3.89 (s, 3H), 3.88 (s, 3H), 3.40-3.34 (m, 2H), 2.67- 2.63 (m, 2H). Example 2: 4-(5,6-Dimethoxy-l,3-benzothiazol-2-yl)-2-methyl-4-oxobutano ic acid

5,6-dimethoxybenzo[d]thiazole (l.58g, 8.09mmol) was added to a sealed tube and back evacuated with N 2 (2x). THF (40mL) was added, and the reaction mixture was cooled to -78°C. rt-BuLi (1.5M in Hex, 5.6mL, 8.9mmol) was added, and the reaction mixture was stirred at -78°C for 30 min. 3-methyldihydrofuran-2,5-dione (l.02g, 8.90mmol) was added, and the reaction mixture was allowed to warm to RT over a period of 4 hours. HC1 (1N) was added until the aqueous layer was pH ~ 4. The aqueous layer was then extracted with EtOAc (3x). The organic layers were combined, dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by reverse phase chromatography (eluting ACN/H 2 0 with 0.05% TFA). The fractions containing all product isomers were combined, diluted with H 2 0, and extracted with EtOAc (3x). The organics were combined, dried over MgS0 4 , filtered, and concentrated under reduced pressure. The racemic mixture was resolved by Chiral-SFC

(CHIRACEL OJ-H (250mmx2lmm), 25% MeOH in C0 2 ) to afford four peaks. Concentration of the third eluting peak afforded 4-(5,6-dimethoxy-l,3-benzothiazol-2-yl)-2-methyl-4- oxobutanoic acid. LCMS (C I4 H I6 N0 5 S) (ES, m/z): 310 [M+H] + . 1H NMR (500MHz, MeOD- d 4 ) d 7.65 (s, 1H), 7.59 (s, 1H), 3.96 (s, 3H), 3.97 (s, 3H), 3.69 (dd, =l8Hz, 8.8Hz, 1H), 3.28 (dd, =l8Hz, 5.5Hz, 1H), 3.15-3.08 (m, 1H), 1.33 (d, =7.3Hz, 3H).

Example 3: (A)-4-(5-Bromo-6-methoxybenzo[dlthiazol-2-vB-2-methyl-4-oxob utanoic acid

Step 1: Methyl 2-((3-bromo-4-methoxyphenyl)amino)-2-oxoacetate

Methyl 2-chloro-2-oxoacetate (l.93mL, 20.8mmol) was added dropwise over a period of 5 min to a stirring mixture of 3-bromo-4-methoxyaniline (4.00g, l9.8mmol), A-ethyl- /V-isopropylpropan-2-amine (4.03mL, 22.8 mmol), and CH 2 Cl 2 (lOOmL) at 0°C. The reaction mixture was stirred for an additional 30 min. The reaction mixture was diluted with H 2 0 (l50mL) and then extracted with DCM (2xl00mL). The organic layers were combined, dried over MgS0 4 , filtered, and concentrated under reduced pressure to afford methyl 2-((3-bromo-4- methoxyphenyl)amino)-2-oxoacetate that was used without purification. 'fl NMR (499 MHz, CDCl 3 ) d 8.77 (s, 1H), 7.85 (d, =2.2Hz, 1H), 7.63 (dd, =8.8Hz, 2.2Hz, 1H), 6.92 (d, =8.9Hz, 1H), 3.99 (s, 3H), 3.91 (s, 3H).

Step 2: Methyl 2-((3-bromo-4-methoxyphenyl)amino)-2-thioxoacetate

Lawesson’s reagent (l.2lg, 2.98mmol) was added to a mixture of methyl 2-((3- bromo-4-methoxyphenyl)amino)-2-oxoacetate (l.56g, 5.4lmmol) in toluene (50mL). The reaction mixture was stirred and heated at 85°C for 17 hours. The reaction mixture was cooled, filtered, and washed with DCM. The filtrate was concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAC in DCM) to afford methyl 2- ((3-bromo-4-methoxyphenyl)amino)-2-thioxoacetate. LCMS (C H H I i BrN0 3 S) (ES, m/z): 304, 306 [M+H] + . X H NMR (499 MHz, CDCl 3 ) d 10.48 (s, 1H), 8.38-8.12 (m, 1H), 8.04-7.85 (m, 1H), 6.96 (d, =8.9Hz, 1H), 4.01 (s, 3H), 3.94 (s, 3H).

Step 3: 5-Bromo-6-methoxybenzo[d]thiazole-2-carboxylic acid

KOH (2N, 20mL, 40mmol) was added to a mixture of methyl 2-((3-bromo-4- methoxyphenyl)amino)-2-thioxoacetate (l.Olg, 3.32mmol) in CH2CI2 (lOmL). The reaction mixture was stirred for 10 min. at RT. The reaction mixture was partially concentrated under reduced pressure, and the resulting mixture was then stirred vigorously. A solution of potassium ferricyanide(III) hydrate (3.46g, 9.96mmol) in H 2 0 (20mL) was added to the reaction mixture. The reaction mixture was stirred for 10 min. The reaction mixture was acidified to pH ~ 2 with HC1 (2N). The reaction mixture was diluted with H 2 0 (50mL). The reaction mixture was stirred vigorously for 16 hours. The reaction mixture was filtered, and the collected materials were washed with H 2 0 (2x20mL), ACN (2x1 OmL), and Et 2 0 (lOmL). The washed materials were dried under reduced pressure to afford 5-bromo-6-methoxybenzo[d]thiazole-2-carboxylic acid that was used without purification. 'H NMR (499 MHz, D MS 0-6 ,) d 8.42 (s, 1H), 7.94 (s, 1H), 3.95 (s, 3H).

Step 4: 5-Bromo-6-methoxybenzo[d]thiazole-2-carbonyl chloride

A mixture of 5-bromo-6-methoxybenzo[d]thiazole-2-carboxylic acid (lOOmg,

0.35mmol) in CH2CI2 (2mL) was stirred and cooled to 0°C. DMF (0.005mL, 0.07mmol) and (COCl)2 (0.064mL, 0.73mmol) were added to the reaction mixture in that order at 0°C. The reaction mixture was warmed to RT and stirred for an additional 20 min. The reaction mixture was concentrated under reduced pressure to afford 5-bromo-6-methoxybenzo[d]thiazole-2- carbonyl chloride, which was used without purification.

Step 5: Methyl (S)-4-(5-bromo-6-methoxybenzo[dlthiazol-2-yl)-2-methyl-4-oxo butanoate

A mixture of CuCl (38mg, 0.38mmol) in THF (0.25mL) was sparged with N 2 .

The reaction mixture was stirred and cooled to 0°C. (i?)-(3-methoxy-2-methyl-3-oxopropyl) zinc(II) bromide (0.50M in THF, 2.2mL, l.lmmol) was added dropwise to the reaction mixture over a period of 2 min. The reaction mixture was stirred for 10 min. A solution of 5-bromo-6- methoxybenzo[d]thiazole-2-carbonyl chloride (l06mg, 0.232mmol) in degassed NMP (2mL) was added to the reaction mixture over a period of 10 min. The reaction mixture was stirred for an additional 10 min. The reaction mixture was quenched by the dropwise addition of concentrated aqueous NH 3 (2mL). The reaction mixture was diluted with EtOAc (30mL) and washed with H 2 0 (3x40mL). The organic layers were separated, dried over Na 2 S0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography

(eluting EtOAc in Hex) to afford (<S)-methyl 4-(5-bromo-6-methoxybenzo[d] thiazol-2-yl)-2- methyl-4-oxobutanoate. LCMS (Ci 4 Hi 5 BrN0 4 S) (ES, m/z): 372, 374 [M+H] + . X H NMR (499

MHz, CDCl 3 ) d 8.37 (s, 1H), 7.39 (s, 1H), 4.02 (s, 3H), 3.78-3.73 (m, 1H), 3.72 (s, 3H), 3.31 (dd,

J=l8.lHz, 5.1HZ, 1H), 3.23-3.15 (m, 1H), 1.34 (d, =7.lHz, 3H).

Step 6: (S)-4-(5-Bromo-6-methoxybenzo[dlthiazol-2-yl)-2-methyl-4-oxo butanoic acid

KOH (0.50M in H 2 0, 0.27mL, 0T3mmol) was added dropwise to a stirred mixture of (L')- methyl 4-(5-bromo-6-methoxybenzo[d]thiazol-2-yl)-2-methyl-4-oxobuta noate (24.8mg, 0.0670mmol) in 2-propanol (0.5mL). The reaction mixture was stirred for an additional 15 min at RT. The reaction mixture was acidified with HC1 (1.0N) to pH ~ 2. The reaction mixture was stirred for 5 min. The reaction mixture was filtered, and the collected materials were washed with H 2 0 (3x2mL). The washed materials were dissolved in ~2mL of DMSO and then purified prep-HPLC (eluting ACN/H 2 0 with 0.1% TFA) to afford (L')-4-(5- bromo-6-methoxybenzo[d]thiazol-2-yl)-2-methyl-4-oxobutanoic acid. LCMS (Ci 3 Hi 3 BrN0 4 S) (ES, m/z): 358, 360 [M+H] + . X H NMR (499 MHz, DMSO-c/ 6 ) d 12.31 (s, 1H), 8.53 (s, 1H), 7.99 (s, 1H), 3.97 (s, 3H), 3.59 (dd, =l8. lHz, 8.9Hz, 1H), 3.22 (dd, =l8. lHz, 5.0Hz, 1H), 3.01-2.93 (m, 1H), 1.22 (d, =7.2Hz, 3H).

Example 4: 4-(4-Fluoro-5,6-dimethoxybenzoldlthiazol-2-yl)-2-methyl-4-ox obutanoic acid

SELECTFLUOR (82mg, 0.23mmol) was added to a mixture of 4-(5,6-dimethoxy- benzo[d]thiazol-2-yl)-2-methyl-4-oxobutanoic acid (Example 2) (34mg, O. l lmmol) in ACN (lmL). The mixture was stirred at 85°C for 16 hours. The reaction mixture was cooled to RT and then concentrated under reduced pressure. The residue was purified by reverse phase HPLC (eluting ACN in H 2 0 with 0.1% TFA) to afford 4-(4-fluoro-5,6-dimethoxybenzo[d]thiazol-2-yl)- 2-methyl-4-oxobutanoic acid. LCMS (C I4 H I5 FN0 5 S) (ES, m/z) 328 [M+H] + . ' H NMR (499 MHz, DMSO-r¾) d 12.32 (s, 1H), 7.76 (s, 1H), 3.96 (s, 3H), 3.92 (s, 3H), 3.62 (dd, =l8. lHz, 8.8Hz, 1H), 3.24 (dd, =l8. lHz, 4.5Hz, 1H), 3.03-2.92 (m, 1H), 1.24 (d, =7.0Hz, 3H).

Example 5: 4-(5,6-Dimethoxythieno|2,3-blnyridin-2-yl)-4-oxobutanoic acid

A mixture of 5-bromo-2,3-dimethoxypyridine (l.50g, 6.88mmol), potassium trifluoro(vinyl)borate (l.84g, l3.8mmol), [l,l'-bis (diphenylphosphino) ferrocene] dichloro- palladium (II) (0.503g, 0.688mmol), and K 2 CO 3 (2.85g, 20.6mmol) in dioxane (l5mL) and H 2 0 (l.5mL) was degassed and backfilled with N 2 three times at 25°C. The reaction mixture was stirred and heated to 80°C for 12 hours. The reaction mixture was diluted with H 2 0 (20mL) and EtOAc (20mL). The reaction mixture was then extracted with EtOAc (3x20mL). The organic layers were combined, washed with brine (20mL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in PE) to afford 2,3-dimethoxy-5-vinylpyridine. LCMS (C9H12NO2) (ES, m/z): 166 [M+H] + . 'H NMR (400MHz, MeOD-ri 4 ) d 7.63 (d, =l.6Hz, 1H), 7.36 (d, =l.8Hz, 1H), 6.73-6.63 (m, 1H), 5.73 (d, =l7.6Hz, 1H), 5.22 (d, J=l l.0Hz, 1H), 3.93 (s, 3H), 3.86 (s, 3H).

Step 2: 5, 6-Dimethoxynicotinaldehyde

NMO (3.83g, 32.7mmol) and 0s0 4 (0.040M in ¾0, 42mL, l.7mmol) were added to a mixture of 2,3-dimethoxy-5-vinylpyridine (2.70g, l6.3mmol) in THF (60mL) and H2O (l5mL). The reaction mixture was stirred at RT for 30 min. NaI0 4 (6.99g, 32.7mmol) was added, and the reaction mixture was stirred at RT for 12 hours. The reaction mixture was diluted with H2O (50mL) and EtOAc (50mL). The reaction mixture was extracted with EtOAc (3x50 mL). The organic layers were combined, washed with brine (50mL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in PE) to afford 5,6-dimethoxynicotinaldehyde. LCMS (CxHioNOri (ES, m/z): 168 [M+H] + . X H NMR (400MHz, CDCf-ri) 5=9.94 (s, 1H), 8.21 (d, =l.8Hz, 1H), 7.48 (d, J=l.8Hz, 1H), 4.12 (s, 3H), 3.94 (s, 3H).

Step 3: (5 6-Dimethoxypyridin-3-yl)methanol

NaBH (267mg, 7.02mmol) was added to a mixture of 5,6-dimethoxynicotin- aldehyde (490mg, 2.93mmol) in MeOH (l3mL) and was stirred at RT for 1 hour. The reaction mixture was concentrated under reduced pressure and then diluted with H 2 0 (5.0mL). The mixture was extracted with EtOAc (3x3mL). The organic layers were combined, dried over MgS0 4 , filtered, and concentrated under reduced pressure to afford (5,6-dimethoxypyridin-3- yl)methanol that was used without purification.

NBS (968mg, 5.44mmol) was added to a mixture of (5,6-dimethoxypyridin-3- yl)methanol (6l0mg, 3.6lmmol) in AcOH (0.05mL) and ACN (20mL). The reaction mixture was stirred at RT for 7 hours. The reaction mixture was quenched with H 2 0 (25mL) and extracted with EtOAc (3x26mL). The organic layers were combined, dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in PE) to afford (2-bromo-5,6-dimethoxypyridin-3-yl)methanol. LCMS (CgHnBrNOs) (ES, m/z): 248, 250 [M+H] + .

Step 5: 2-Bromo-5, 6-dimethoxynicotinaldehyde

Dess-Martin periodinane (539mg, l.27mmol) was added to a mixture of (2- bromo-5,6-dimethoxypyridin-3-yl)methanol (2l0mg, 0.847mmol) in DCM (lO.OmL). The reaction mixture was stirred at RT for 2 hours. H 2 0 (20.0mL), aq Na 2 S0 4 (l5.0mL), aq

NaHC0 3 (25.0mL), and EtOAc (l5.0mL) were added to the reaction mixture. The reaction mixture was extracted with EtOAc (3xl5mL). The organic layers were combined, dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by prep- TLC (eluting EtOAc in PE) to afford 2-bromo-5,6-dimethoxynicotinaldehyde. LCMS

(C 8 H 9 BrN0 3 ) (ES, m/z): 246, 248 [M+H] + . 1H NMR (400MHz, CDCl 3 -d) d 10.17 (s, 1H), 7.51

(s, 1H), 4.13 (s, 3H), 3.93 (s, 3H).

Step 6: 5 6-Dimethoxythieno[2 3-b lpyridine-2-carboxylic acid

A mixture of 2-bromo-5,6-dimethoxynicotinaldehyde (2l5mg, 0.874mmol), K 2 C0 3 (362mg, 2.62mmol) and methyl 2-mercaptoacetate (O. lOmL, l. lmmol) in DMF (5.0mL) was degassed and backfilled with N 2 three times. The reaction mixture was stirred at 60°C for 12 hours. The reaction mixture was cooled to RT and then concentrated under reduced pressure. The residue was diluted with H 2 0 (lOmL) and EtOAc (lOmL), and the mixture was then extracted with additional EtOAc (3xl0mL). The combined organic layers were discarded. The aqueous layer was then acidified to pH ~ 5-6 with HC1 (1N). The aqueous layer was then extracted with EtOAc (3x5mL). The organic layers were combined, washed with brine (lOmL), dried over MgS0 , filtered, and concentrated under reduced pressure. The residue was purified by prep-TLC (eluting EtOAc in PE) to afford 5,6-dimethoxythieno[2,3-b]pyridine-2-carboxylic acid that was used without purification. LCMS (C IO H I0 N0 4 S) (ES, m/z): 240 [M+H] + . ' H NMR (400MHz, DMSO-de) d 7.93 (s, 1H), 7.81 (s, 1H), 3.98 (s, 3H), 3.85 (s, 3H). Step 7: Methyl 3-(5, 6-dimethoxythieno [2, 3-bJpyridin-2-yl)-3-oxopropanoate

CDI (l32mg, 0.8l5mmol) was added to a mixture of 5,6-dimethoxythieno[2,3- b]pyridine-2-carboxylic acid (l30mg, 0.543mmol) in ACN (5.0mL). The reaction mixture was stirred at RT under N 2 for 1 hour. A mixture of potassium 3-methoxy-3-oxopropanoate (l27mg, 0.8l5mmol) and MgCT (78mg, 0.82mmol) was added to the reaction mixture. The reaction mixture was stirred at RT for 12 hours. The reaction mixture was concentrated under reduced pressure, and the residue was diluted with H 2 0 (lOmL), acidified to pH ~ 5-6 with HC1 (10% in H 2 0), and extracted with EtOAc (3x1 OmL). The organic layers were combined, washed with brine (lOmL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by prep-TLC (eluting EtOAc in PE) to afford methyl 3-(5,6-dimethoxythieno[2,3- b]pyridin-2-yl)-3-oxopropanoate. LCMS (C13H14NO5S) (ES, m/z): 296 [M+H] + . X H NMR (400MHz, CDCl 3 -d) d 7.82 (s, 1H), 7.38 (s, 1H), 4.13 (s, 3H), 3.99 (s, 2H), 3.94 (s, 3H), 3.77 (s, 3H).

Step 8: Dimethyl 2-(5, 6-dimethoxythieno [2, 3-blpyridine-2-carbonyl) succinate

Methyl 2-bromoacetate (0.02mL, 0.2mmol) and K 2 C0 3 (32mg, 0.24 mmol) were added to a mixture of methyl 3-(5,6-dimethoxythieno[2,3-b]pyridin-2-yl)-3-oxopropanoate (63mg, 0.21 mmol) in DMF (5. OmL). The reaction mixture was stirred at RT for 12 hours. H 2 0 (5mL) and EtOAc (5mL) were added to the reaction mixture, and the mixture was extracted with EtOAc (3x5mL). The organic layers were combined, washed with brine (lOmL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by prep- TLC (eluting EtOAc in PE) to afford dimethyl 2-(5,6-dimethoxythieno[2,3-b]pyridine-2- carbonyl)succinate. LCMS (CieHigNOyS) (ES, m/z): 368 [M+H] + .

Step 9: 4-(5, 6-Dimethoxythieno[2,3-blpyridin-2-yl)-4-oxobutanoic acid K 2 C03 (75mg, 0.54mmol) was added to a mixture of dimethyl 2-(5,6- dimethoxythieno[2,3-b]pyridine-2-carbonyl)succinate (40mg, O. l lmmol) in THF (l.OmL) and H 2 0 (l.OmL). The reaction mixture was stirred at RT for 1 hour, and then the mixture was heated to 80°C and stirred for an additional 12 hours. The reaction mixture was acidified with HC1 (1M in H 2 0) to pH ~ 6. The reaction mixture was purified directly by prep-HPLC (eluting ACN in H 2 0, with 0.1% TFA) to afford 4-(5,6-dimethoxythieno[2,3-b]pyridin-2-yl)-4- oxobutanoic acid. LCMS (C I3 H I4 N0 5 S) (ES, m/z): 296 [M+H] + . 1H NMR (400MHz, MeOD- d 4 ) 5=8.06 (s, 1H), 7.68 (s, 1H), 4.06 (s, 3H), 3.92 (s, 3H), 3.34 (t, =6.3Hz, 2H), 2.73 (t, =6.5Hz, 2H).

Example 6: 4-(5,6-Dimethoxythieno|2,3-/ |pyndin-2-yl)-4-oxobutanoic acid

CDI (l02mg, 0.627mmol) was added to a mixture of 5,6-dimethoxythieno[3,2-Z>] pyridine-2-carboxylic acid (lOOmg, 0.4l8mmol) in ACN (5mL). The reaction mixture was stirred at RT under N 2 for 2 hours. A mixture of potassium 3-methoxy-3-oxopropanoate (98mg, 0.63mmol) and MgCT (60mg, 0.63mmol) was added to the solution. The mixture was stirred at RT for 12 hours. The reaction mixture was concentrated under reduced pressure and and then diluted with H 2 0 (lOmL). The mixture was extracted with EtOAc (3x20mL). The organic layers were combined, washed with brine (20mL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by prep-TLC (eluting EtOAc in PE) to afford methyl 3-(5,6-dimethoxythieno[3,2-Z>]pyridin-2-yl)-3-oxopropanoa te. LCMS (C13H14NO5S) (ES, m/z): 296 [M+H] + . X H NMR (400 MHz, CDCl 3 ) d 7.96 (s, 1H), 7.42 (s, 1H), 4.11 (s, 3H),

4.02 (s, 2H), 3.99 (s, 3H), 3.78 (s, 3H).

Step 2: Dimethyl 2-{5, 6-dimethoxythieno [ 3, 2-b]pyridine-2-carbonyl) succinate K 2 CO 3 (l9mg, O.l4mmol) and methyl 2-bromoacetate (2lmg, O. l4mmol) were added to a mixture of methyl 3-(5,6-dimethoxythieno[3,2-Z>]pyridin-2-yl)-3-oxopropanoa te (40mg, 0. l4mmol) in DMF (lmL). The reaction mixture was stirred at RT for 12 hours. The reaction mixture was diluted with EtOAc (50mL), washed with brine (3x5mL), dried over MgSCh. filtered, and concentrated under reduced pressure to afford dimethyl 2-(5,6- dimethoxythieno[3,2-Z>]pyridine-2-carbonyl)succinate that was used without purification. LCMS (C I6 H I8 N0 7 S) (ES, m/z): 368 [M+H] + .

K2CO3 (37mg, 0.27mmol) was added to a mixture of dimethyl 2-(5,6- dimethoxythieno| 2.3-6 |pyridine-2-carbonyl)succinate (25mg, 0.054mmol) in THF (l.OmL) and H 2 0 (l.OmL). The reaction mixture was stirred and heated to 80°C for 12 hours. The reaction mixture was cooled to RT, acidified with HC1 (1.0M in H 2 0) to pH ~ 6, and then was directly purified by reverse phase HPLC (eluting ACN in H 2 0, with 0.1% TFA) to afford 4-(5,6- dimethoxythieno[3,2-b]pyridin-2-yl)-4-oxobutanoic acid. LCMS (C13H14NO5S) (ES, m/z): 296 [M+H] + . X H NMR (400 MHz, MeOD-d 4 ) d 8.07 (s, 1H), 7.74 (s, 1H), 4.04 (s, 3H), 3.94 (s, 3H), 3.35 (t, =6.4Hz, 2H), 2.74 (t, ./ 6 4Hz. 2H).

Example 7 and Example 8: (R or A)-4-(5,6-Dimethoxythieno[3,2-blpyridin-2-yl)-2-methyl- 4-oxobutanoic acid and (R or A)-4-(5,6-dimethoxythieno[3,2-blpyridin-2-yl)-2-methyl-4- oxobutanoic acid

CS 2 CO 3 (622mg, l.9lmmol) was added to a stirred mixture of tert- butyl 3-(5,6- dimethoxythieno[3,2-b]pyridin-2-yl)-3-oxopropanoate (322mg, 0.954mmol) in DMF (3mL) at 25°C. A mixture of fer/-butyl 2-bromopropanoate (2l0mg, l.OOmmol) in DMF (lmL) was added dropwise to the reaction mixture. The reaction mixture was stirred at RT for 5 hours. Additional /er/-butyl 2-bromopropanoate (63mg, 0.030mmol) was added, and the reaction mixture was stirred for 1 hour. Additional /er/-butyl 2-bromopropanoate (63mg, 0.030mmol) was added, and the reaction mixture was stirred overnight. The reaction mixture was diluted with isopropyl acetate (75mL) and sodium citrate (10% w/v in H 2 0, 40mL). The layers were separated, and the aqueous layer was extracted with additional isopropyl acetate (40mL). The organic layers were combined, washed with brine, dried over anhydrous Na^SCri. filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAC in Hex) to afford di-/er/-butyl 2-(5,6-dimethoxythieno[3,2-b]pyridine-2- carbonyl)-3-methylsuccinate. LCMS (C23H32NO7S) (ES, m/z): 466 [M+H] + .

Step 2: (R or S)-4-(5 6-Dimethoxythieno [3 2-blt>yridin-2-yl)-2-methyl-4-oxobutanoic acid and (R

TFA (7mL) was added to di-/er/-butyl 2-(5,6-dimethoxythieno[3,2-b]pyridine-2- carbonyl)-3-methylsuccinate (41 lmg, 0.883mmol), and the mixture was then stirred and heated to 50°C for 5 hours. The reaction mixture was cooled to RT and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford 4-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-2-methyl-4-oxobut anoic acid as a racemate. LCMS (C I4 H I6 N0 5 S) (ES, m/z): 310 [M+H] + . *H NMR (500 MHz, CDCI3) d 7.99 (s, 1H), 7.43 (s, 1H), 4.11 (s, 3H), 3.99 (s, 3H), 3.49 (dd, =l7.2Hz, 7.7Hz, 1H), 3.22 (dt, =l3.6Hz, 7.0Hz, 1H), 3.11 (dd, =l7.2Hz, 5.5Hz, 1H), 1.36 (d, =7. lHz, 3H). The racemic mixture was resolved by Chiral-SFC (Column CHIRALPAK AD-H, 21 x 250 mm, with 40% MeOH (+0.25% DMEA) in CO2) affording two peaks with retention times of 3.57 min. and 5.48 min. Concentration of the two peaks afforded the two enantiomers of 4-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-2- methyl-4-oxobutanoic acid.

Peak 1 ( R or < S -4-(5,6-Dimethoxythieno[3,2-b]pyridin-2-yl)-2-methyl-4- oxobutanoic acid (Example 7): LCMS (C I4 H I6 N0 5 S) (ES, m/z): 310 [M+H] + . 1H NMR (500 MHz, CDCI3) d 7.98 (s, 1H), 7.43 (s, 1H), 4.11 (s, 3H), 3.99 (s, 3H), 3.49 (dd, =l7. lHz, 7.5Hz, 1H), 3.44-3.15 (m, 1H), 3.11 (dd, =l7. lHz, 5.3Hz, 1H), 1.36 (d, =7.0Hz, 3H). Peak 2(7? or 5')-4-(5.6-Dimethoxythieno|3.2-b|pyridin-2-yl)-2-methyl-4- oxobutanoic acid (Example 8): LCMS (C14H16NO5S) (ES, m/z): 310 [M+H] + . *H NMR (500 MHz, CDCI3) d 7.98 (s, 1H), 7.43 (s, 1H), 4.11 (s, 3H), 3.99 (s, 3H), 3.49 (dd, =l7.2Hz, 7.6Hz, 1H), 3.20 (dt, =l4.2Hz, 6.9Hz, 1H), 3.11 (dd, =l7.2Hz, 5.6Hz, 1H), 1.36 (d, =7.lHz, 3H).

Example 9: Cis-2- blnyridine-2-carbonyl)cvclonronane-l-

carboxylic acid

Cu (0.27g, 4.3mmol) was added to a mixture of 5,6-dimethoxythieno[3,2- b]pyridine-2-carboxylic acid (0.60g, 2.5 mmol) in quinoline (5.9mL, 50mmol), and the reaction mixture was heated to l90°C for 2 hours. Upon cooling to RT, the reaction mixture was diluted with EtOAc and aq HC1 (2N). The mixture was filtered through CELITE, and the filtrate was washed with H 2 0, aq sat NaHCCE, and brine. The organics were separated, dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography to afford 5,6-dimethoxythieno[3,2-b]pyridine. LCMS (C9H10NO2S) (ES, m/z): 196 [M+H] + . X H NMR (500 MHz, DMSO-r¾) d 7.93 (s, 1H), 7.76 (d, =5.4Hz, 1H), 7.32 (d, =5.4Hz, 1H), 3.92 (s, 3H), 3.84 (s, 3H).

5,6-dimethoxythieno[3,2-b]pyridine (0. l5g, 0.77mmol) was added to a sealed tube, and the tube was evacuated and then back-filled with N 2 . THF (3.8 mL) was added, and the mixture was cooled to -78°C. «-BuLi (1.6M in Hex, 0.53mL, 0.85mmol) was added, and the mixture was stirred at -78°C for 30 min. The reaction mixture was then added to a mixture of 3- oxabicyclo[3.l.0]hexane-2,4-dione (0.43g, 3.8mmol) in THF (3.0mL) that had been pre-cooled to -78°C. The reaction mixture was stirred at -78°C for 30 min. The reaction mixture was allowed to warm to RT and stirred for an additional 30 min. The reaction mixture was diluted with H 2 0 and EtOAc. The aqueous layer was separated and then acidified to a pH ~ 4 with aqueous HC1 (1.0N). The aqueous layer was then extracted with EtOAc (2x). The organic layers were combined, dried over MgS0 4 , filtered, and concentrated under reduced pressure.

The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford the desired product as a mixture of isomers. The cis racemate was then resolved by CHIRAL-SFC (Column AD-H (21x250 mm) eluting 30% MeOH with 0.25% DMEA in CO ) to afford cis- 2- (5,6-dimethoxythieno[3,2-b]pyridine-2-carbonyl)cyclopropane- l-carboxylic acid (retention time 7.23 min). LCMS (C I4 H I4 N0 5 S) (ES, m/z): 308 [M+H] + . X H NMR (600 MHz, DMSO-rid) d 8.22 (s, 1H), 7.93 (s, 1H), 3.92 (s, 3H), 3.84 (s, 3H), 3.09-2.96 (m, 1H), 2.28-2.19 (m, 1H), 1.55- 1.45 (m, 1H), 1.28-1.21 (m, 1H).

Example 10: CV)-4-(5-Chloro-6-methoxythieno|3,2-blnyridin-2-yl)-2-methyl -4-oxobutanoic acid

Step 1: 5-Chloro-6-methoxythieno[3,2-blvyridine-2-carbonyl chloride

ci

Phosphorous oxychloride (l. l7mL, l2.5mmol) was added dropwise to a stirred mixture of 5,6-dimethoxythieno[3,2-b]pyridine-2-carboxylic acid (l.OOg, 4.lmmol) in DMF (10.45 ml) at 0°C under N 2 . After 10 min, the reaction mixture was allowed to warm to RT. The reaction mixture was then heated to l00°C and stirred for 45 min. The reaction mixture was added to ice water (lOOmL) and stirred. The mixture was filtered, and the collected materials were washed with H 2 0 (2x30mL) and Hex (50mL). The washed materials were diluted with Et 2 0 (50mL) and again filtered. The filtered materials were dissolved in CH 2 Cl 2 (60mL), and the mixture was dried over anhydrous Na 2 S0 4 , filtered, and concentrated under reduced pressure to afford 5-chloro-6-methoxythieno[3,2-b]pyridine-2-carbonyl chloride. 'fl NMR (500 MHz, CDCf) d 8.32 (s, 1H), 7.60 (s, 1H), 4.06 (s, 3H).

Step 2: Methyl ( S)-4-(5-chloro-6-methoxythieno[3,2-blpyridin-2-yl)-2-methyl- 4-oxobutanoate

Cul (0.073g, 0.38mmol) was placed under a vacuum and heated for 1 min. The flask was allowed to cool to RT and was then opened to N 2 . Twice more the flask was evacuated, then backfilled with N 2 . The flask remained under N 2 . THF (2mL) was added, and the reaction mixture was cooled in an ice water bath. A solution of (i?)-(3-methoxy-2-methyl-3- oxopropyl)zinc(II) bromide in THF (0.50M, l.68mL, 0.84mmol) was added dropwise to the reaction mixture over a period of 5 min. The reaction mixture was stirred for 105 min. at 0°C. A mixture of 5-chloro-6-methoxythieno[3,2-b]pyridine-2-carbonyl chloride (0.200g, 0.763mmol) in NMP (3mL) was then added dropwise over 5 min. The reaction mixture was then stirred for 3 hours at 0°C. The reaction mixture was then added to a stirred mixture of isopropyl acetate (50mL) and sodium citrate (20% w/v in H 2 0, 50mL). After stirring for 20 min, the layers were separated, and the aqueous layer was extracted with additional isopropyl acetate (30mL). The organic layers were combined, washed with brine (2x50mL), dried over anhydrous Na 2 S0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford fV)-methyl 4-(5-chloro-6-methoxythieno [3,2- b]pyridin-2-yl)-2-methyl-4-oxobutanoate. LCMS (C14H15CINO4S) (ES, m/z): 328 [M+H] + . ' H NMR (500 MHz, CDCf) d 7.99 (s, 1H), 7.60 (s, 1H), 4.03 (s, 3H), 3.72 (s, 3H), 3.51 (dd, =l7.2Hz, 7.9Hz, 1H), 3.21-3.12 (m, 1H), 3.06 (dd, =l7.2Hz, 5.2Hz, 1H), 1.32 (d, =7. lHz, 3H).

LiOH H 2 0 (0.055g, l.3lmmol) was added to a mixture of fS')-methyl 4-(5-chloro- 6-methoxythieno[3,2-b]pyridin-2-yl)-2-methyl-4-oxobutanoate (0. l07g, 0.326mmol) in H 2 0 (0.5mL) and THF (0.5mL). The reaction mixture was heated to 45°C and stirred for 1 hour. Additional THF (0.5mL) and H 2 0 (0.5mL) were added to the reaction mixture. After stirring for an additional 4 hours, the reaction mixture was cooled to RT and partitioned between EtOAc (5mL) and H 2 0 (5mL). AcOH was added until pH ~ 4. The layers were separated, and the aqueous layer was extracted with additional EtOAc (5mL). The organic layers were combined, washed with brine (5mL), dried over anhydrous Na 2 S0 4 . filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting [25% EtOH in EtOAc] in Hex) to afford fV)-4-(5-chloro-6-methoxythieno|3.2-b|pyridin-2-yl)-2-methyl -4- oxobutanoic acid. LCMS (C13H13CINO4S) (ES, m/z): 314 [M+H] + . X H NMR (500 MHz,

CDCf) d 8.02 (s, 1H), 7.62 (s, 1H), 4.04 (s, 3H), 3.52 (dd, =l7.4Hz, 7.9Hz, 1H), 3.27-3.17 (m, 1H), 3.11 (dd, =l7.4Hz, 5.3Hz, 1H), 1.38 (d, =7.2Hz, 3H). Example 11 and Example 12: (R or V)-4- 2-yl)-2-ethyl-

4-oxobutanoic acid and (R or V)-4- b|pyridin-2-yl)-2-ethyl-4-

oxobutanoic acid

A mixture of /e/V-butyl 3-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-3- oxopropanoate (50mg, 0. l5mmol) and CS 2 CO 3 (97mg, 0.30mmol) in NMP (0.5mL) was stirred at RT for 15 min. Methyl 2-bromobutanoate (0.026mL, 0.22mmol) was added to the reaction mixture, which was then stirred at RT for 40 hours. The reaction mixture was diluted with EtOAc (30mL) and washed with H 2 0 (30mL). The organic layer was separated, dried over Na 2 S0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford l-/er/-butyl 4-methyl 2-(5,6- dimethoxythieno[3,2-b]pyridine-2-carbonyl)-3-ethylsuccinate as a mixture of diastereomers. LCMS (C 2I H 28 N0 7 S) (ES, m/z): 438 [M+H] + .

Step 2: Methyl 4-(5, 6-dimethoxythieno[3,2-blpyridin-2-yl)-2-ethyl-4-oxobutanoate

A mixture of TFA (lmL) and l-/er/-butyl 4-methyl 2-(5,6-dimethoxythieno[3,2- b]pyridine-2-carbonyl)-3-ethylsuccinate (1 lOmg, 0.25lmmol) was stirred and heated to 70°C for 1 hour. The reaction mixture was cooled to RT and diluted with DCM (lOmL). The reaction mixture was basified with KOH (10N) to pH ~ 6. The reaction mixture was extracted with DCM (2x20mL). The organic layers were combined, dried over Na 2 S0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford methyl 4-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-2-ethyl-4-oxobuta noate. LCMS (C I6 H 20 NO 5 S) (ES, m/z): 338 [M+H] + . 1H NMR (499 MHz, CDCl 3 ) d 7.99 (s, 1H), 7.43 (s, 1H), 4.11 (s, 3H), 3.99 (s, 3H), 3.72 (s, 3H), 3.47 (dd, J= 16.7Hz, 8.6Hz, 1H), 3.13-3.01 (m, 2H), 1.74-1.66 (m, 2H), 0.99 (t, .7=7.4 Hz. 3H).

Step 3: 7R or S )-4-(5, 6-Dimethoxythieno[3,2-blvyridin-2-yl)-2-ethyl-4-oxobutanoic acid and 7R or S )-4-(5, 6-dimethoxythienof 3, 2-b lpyridin-2-yl)-2-ethyl-4-oxobutanoic acid

KOH (0.5M in H 2 0, l.2mL, 0.6mmol) was added dropwise to a mixture of methyl 4-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-2-ethyl-4-oxobuta noate (66.4mg,

0. l97mmol) in 2-propanol (lmL). The reaction mixture was stirred for 30 min at RT. The reaction mixture was then heated to 70°C for 15 min. The reaction mixture was cooled to RT and acidified to pH ~ 2 with HC1 (1N). The reaction mixture was extracted with DCM

(2x20mL). The organic layers were combined, dried over Na 2 SC>4. filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford the racemic product. The racemate was resolved by CHIRAL-SFC (Column AD-H (250mm*2lmm) eluting 40% MeOH (+0.25% DMEA) in C0 2 ) to afford two peaks with retention times of 3.7 min and 5.9 min. Concentration of the two peaks afforded the two enantiomers of 4-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-2-ethyl-4-oxobuta noic acid.

Peak 1 ( R or 5')-4-(5.6-Dimethoxythieno|3.2-b|pyridin-2-yl)-2-ethyl-4- oxobutanoic acid (Example 11): LCMS (C I5 H I8 N0 5 S) (ES, m/z) 324 [M+H] + . ' H NMR (499 MHz, DMSO-i¾) d 11.94 (br s, 1H), 8.30 (s, 1H), 7.98 (s, 1H), 3.96 (s, 3H), 3.89 (s, 3H), 3.44 (dd, =l7.4Hz, 9.6Hz, 1H), 3.10 (dd, .7=17.4Hz, 3.6Hz, 1H), 2.82-2.73 (m, 1H), 1.68-1.55 (m, 2H), 0.93 (t, =7.3Hz, 3H).

Peak 2 ( R or < S)-4-(5,6-Dimethoxythieno[3,2-b]pyridin-2-yl)-2-ethyl- 4- oxobutanoic acid (Example 12): LCMS (C I5 H I8 N0 5 S) (ES, m/z) 324 [M+H] + . 'H NMR (499 MHz, DMSO-i¾) d 11.94 (br s, 1H), 8.30 (s, 1H), 7.98 (s, 1H), 3.96 (s, 3H), 3.89 (s, 3H), 3.44 (dd, =l7.4Hz, 9.6Hz, 1H), 3.10 (dd, .7=17.4Hz, 3.6Hz, 1H), 2.81-2.73 (m, 1H), 1.68-1.55 (m, 2H), 0.93 (t, =7.3Hz, 3H).

Examnle 13 and Examnle 14: (R or A)- 2-t2-t5.6-Diinethoxythienol3,2-blnyridin-2-yl)-2- oxoethvDpentanoic acid and (R o blpyridin-Z-vD-l-

oxoethvDpentanoic acid

Methyl 2-bromopentanoate (0.042mL, 0.28mmol) was added to a mixture of tert- butyl 3-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-3-oxopropanoate (63mg, O. l9mmol) and CS2C03 (l22mg, 0.375mmol) in NMP (0.5mL). The reaction mixture was stirred at RT for 3 hours. The reaction mixture was diluted with EtOAc (30mL) and washed with H 2 0 (2x3 OmL). The organic layer was separated, dried over Na^SO^ filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford l-te/7-butyl 4-methyl 2-(5,6-dimethoxythieno[3,2-b]pyridine-2-carbonyl)-3- propylsuccinate as a mixture of diastereomers. LCMS (C22H30NO7S) (ES, m/z): 452 [M+H] + .

A mixture of 1 -tert-butyl 4-methyl 2-(5,6-dimethoxythieno[3,2-b]pyridine-2- carbonyl)-3-ethylsuccinate (65mg, O. l4mmol) and TFA (lmL) was stirred and heated to 70°C for 1 hour. The reaction mixture was cooled to RT and then concentrated under reduced pressure to afford methyl 4-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-2-ethyl-4-oxopent anoate, which was used without purification. LCMS (C 17 H 22 NO 5 S) (ES, m/z): 352 [M+H] + .

Step 3: (R or S)- 2-(2-(5, 6-Dimethoxythieno[3,2-blpyridin-2-yl)-2-oxoethyl)pentanoic acid and

KOH (0.50N, l.7mL, 0.85mmol) was added to a mixture of methyl 4-(5,6- dimethoxythieno[3,2-b]pyridin-2-yl)-2-ethyl-4-oxopentanoate (50.0mg, O. l42mmol) and 2- propanol (lmL). The reaction mixture was stirred and heated to 70°C for 40 min. The reaction mixure was cooled to RT, acidified to pH ~ 3 with HC1 (1N), and then was extracted with DCM (2x30mL). The organic layers were combined, dried over Na 2 S0 4 . filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford the racemic product. The racemic mixture was resolved by CHIRAL-SFC (Column AD-H (250mm*2lmm), with 25% MeOH (+0.25% DMEA) in CO ) affording two peaks with retention times of 4.7 min and 6.0 min. Concentration of the two peaks afforded the two enantiomers of 4-(5,6-dimethoxythieno[3,2-b]pyridin-2-yl)-2-ethyl-4-oxopent anoic acid.

Peak 1 ( R or S)- 2-(2-(5,6-Dimethoxythieno[3,2-b]pyridin-2-yl)-2-oxoethyl) pentanoic acid (Example 13): LCMS (C I6 H 20 NO 5 S) (ES, m/z) 338 [M+H] + . ' H NMR (499 MHz, DMSO-ri 6 ) d 12.18 (s, 1H), 8.29 (s, 1H), 7.98 (s, 1H), 3.96 (s, 3H), 3.89 (s, 3H), 3.42 (dd, =l7.6Hz, 9.6Hz, 1H), 3.13 (dd, =l7.5Hz, 4. lHz, 1H), 2.86-2.77 (m, 1H), 1.65-1.48 (m, 2H), 1.43-1.28 (m, 2H), 0.89 (t, =7.3Hz, 3H).

Peak 2 ( R or S)- 2-(2-(5,6-Dimethoxythieno[3,2-b]pyridin-2-yl)-2-oxoethyl) pentanoic acid (Example 14): LCMS (C I6 H 20 NO 5 S) (ES, m/z) 338 [M+H] + . 'H NMR (499 MHz, DMSO-ri 6 ) d 12.18 (s, 1H), 8.29 (s, 1H), 7.98 (s, 1H), 3.96 (s, 3H), 3.89 (s, 3H), 3.42 (dd, =l7.6Hz, 9.6Hz, 1H), 3.13 (dd, =l7.5Hz, 4. lHz, 1H), 2.86-2.77 (m, 1H), 1.65-1.47 (m, 2H), 1.43-1.28 (m, 2H), 0.89 (t, =7.3Hz, 3H).

Examnle 15: 4-(6-Bromo-5-methoxythienol3,2-blnyridin-2-yl)-4-oxobutanoic acid

AcOH (50mL) was added to a mixture of 2-bromomalonaldehyde (3.56g, 23.6mmol) and tert- butyl thiophen-3-ylcarbamate (4.70g, 23.6mmol) at RT under air atmosphere (septum was vented via needle). The reaction mixture was stirred and heated to l00°C for 24 hours. The reaction mixture was then cooled to RT and diluted with EtOAc (300mL). Sat aq NaHCCE was added until gas evolution ceased. The organic layer was separated, washed with brine (50mL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford 6-bromothieno[3,2- b]pyridine. LCMS (C 7 H 5 BrNS) (ES, m/z): 214, 216 [M+H] + . X H NMR (499 MHz, DMSO-ri 6 ) d 8.86 (s, 1H), 8.74 (s, 1H), 8.18 (d, =5.4Hz, 1H), 7.58 (d, =5.4Hz, 1H).

mCPBA (l.49g, 6.63mmol) was added to a mixture of 6-bromothieno[3,2-b] pyridine (l.42g, 6.63mmol) in DCM (50mL) at 0°C under Ar. The reaction mixture was then allowed to warm to RT and stirred for an additional 24 hours. The reaction mixture was then concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting [5% MeOH in EtOAc] in DCM) to afford 6-bromothieno [3, 2-b] pyridine 4-oxide.

LCMS (C 7 H 5 BrNOS) (ES, m/z): 230, 232 [M+H] + .

Step 3: 6-Bromothienof 3 2-b lpyridin-5-yl acetate

A 0 A i

Acetic anhydride (20mL, 2l0mmol) was added to 6-bromothieno [3, 2-b] pyridine 4-oxide (l.38g, 6.00mmol) at RT under N 2 . The reaction mixture was then heated to l40°C and stirred for 4 hours. The reaction mixture was then cooled to RT and diluted with EtOAc (200mL) and H 2 0 (200mL). NaHC0 3 was slowly added portionwise to the reaction mixture until all gas evolution ceased. The organic layer was separated, washed with brine (25mL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting [5% MeOH in EtOAc] in DCM) to afford 6-bromothieno[3,2- b]pyridin-5-yl acetate. LCMS (Cc,H 7 BrN0 2 S-C 2 H 2 0) (ES, m/z): 230, 232 [M+H-acetate] + . ' H NMR (499 MHz, DMSO-ri 6 ) d 9.04 (s, 1H), 8.29 (d, =5.2Hz, 1H), 7.54 (d, =5.4Hz, 1H), 2.41 (s, 3H).

NaOH (2.0M in H 2 0, 4.0mL, 8.0mmol) was added to a solution of 6-bromothieno [3,2-b]pyridin-5-yl acetate (43lmg, l.58mmol) in MeOH (5.0mL) at 20°C under N 2 . The reaction mixture was then stirred for 1 hour at 20°C. The reaction mixture was quenched with HC1 (1.0M in H 2 0, 8.0mL, 8.0mmol) and then diluted by the addition of H 2 0 (lOmL). The reaction mixture was stirred for 30 minutes and then filtered. The collected material was washed with additional H 2 0 (lOmL) and then dried under reduced pressure to afford 6-bromothieno[3,2- b]pyridin-5-ol. LCMS (C 7 H 5 BrNOS) (ES, m/z): 230, 232 [M+H] + . 1H NMR (499 MHz, DMSO-ri 6 ) d 12.65 (s, 1H), 8.59 (s, 1H), 7.91 (d, =5.3Hz, 1H), 6.99 (d, =5. lHz, 1H).

Step 5: 6-Bromo-5-chlorothieno[ 3, 2-b Ipyridine

Phosphorus oxychloride (l5.2mL, l63mmol) was added to 6-bromothieno[3,2- b]pyridin-5-ol (375mg, l.63mmol) at 20°C under N 2 . The reaction mixture was then stirred and heated to l00°C for 2 days. The reaction mixture was cooled to RT and quenched by the dropwise addition of the reaction mixture to a solution of aqueous saturated NaHCCE solution. The reaction mixture was further diluted with EtOAc (250mL) and stirred. The organic layer was separated, washed with brine (25mL), dried over MgS0 4 , filtered, and concentrated under reduced pressure to afford 6-bromo-5-chlorothieno[3,2-b]pyridine which was used without purification. LCMS (C 7 H 4 BrClNS) (ES, m/z): 248, 250 [M+H] + .

Step 6: 6-Bromo-5-methoxythieno [ 3 2-bl pyridine

NAOMe (25% in MeOH, 3.24mL, l4mmol) was added to a mixture of 6-bromo- 5-chlorothieno[3,2-b]pyridine (352mg, l.42mmol) in MeOH (lOmL) at 20°C under N 2 . The reaction mixture was stirred and heated to l00°C for 1 hour in a microwave reactor. The reaction mixture was quenched with citric acid (1.0M in H 2 0, 28mL, 28mmol) and diluted with EtOAc (250mL). The organic layer was separated, washed with brine (25mL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting [5% MeOH in EtOAc] in DCM) to afford 6-bromo-5-methoxythieno [3,2-b]pyridine. LCMS (C 8 H 7 BrNOS) (ES, m/z): 244, 246 [M+H] + . 'H NMR (499 MHz, DMSO-ri 6 ) d 8.78 (s, 1H), 8.09 (d, =5.3Hz, 1H), 7.44 (d, =5.2Hz, 1H), 3.99 (s, 3H).

LDA (2.0M in THF, 0.090 mL, 0.18 mmol) was added to a solution of 6-bromo- 5-methoxythieno[3,2-b]pyridine (40mg, O. l6mmol) in THF (2.0mL) at -78°C. The reaction mixture was stirred for 15 min while warming to approximately -40°C, and was then quenched at -40°C by the addition of a solution of dihydrofuran-2,5-dione (98mg, 0.98mmol) in THF (2.0mL). The reaction mixture was then allowed to warm to 20°C and was stirred for an additional 15 min at 20°C. The reaction mixture was quenched with HC1 (1.0N, 0.20mL, 0.20 mmol) and diluted with EtOAc (lOOmL). The organic layer was separated, washed with brine (lOmL), dried over MgS0 4 , filtered, and concentrated under reduced pressure. The residue was purified by reverse phase HPLC (eluting ACN/water gradient with 0.1% TFA modifier, C-18 stationary phase) to afford 4-(6-bromo-5-methoxythieno[3,2-b]pyridin-2-yl)-4-oxobutanoic acid. LCMS (Ci 2 HnBrN0 4 S) (ES, m/z): 344, 346 [M+H] + . 1H NMR (499 MHz, DMSO-ri 6 ) d 12.22 (br s, 1H), 8.88 (s, 1H), 8.36 (s, 1H), 4.02 (s, 3H), 3.37-3.34 (m, 2H), 2.64-2.60 (m, 2H).

Example 16: 4- )-4-oxobutanoic acid

To a stirred solution of ter/-butyl 3-(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)-3- oxopropanoate (Preparation 2) (21 mg, 0.062mmol) in DMF (310 pL) was added CS2CO3 (24mg, 0.074mmol) followed by /e/V-butyl bromoacetate (9pL, 0.06mmol) at RT. The reaction mixture was stirred at RT for 3 hours, and then diluted with Et 2 0 and H 2 0. The organic layers were separated, washed with brine, dried over Na 2 S04, filtered, and concentrated under reduced pressure to afford di-te/7-butyl 2-[(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)carbonyl]butane dioate, which was used without purification. LCMS (C 2I H 29 N 2 07S) (ES, m/z): 453 [M+H] + .

TFA (l70pL) was added to a stirred solution of di-te/7-butyl 2-[(2,3- dimethoxythieno[2,3-b]pyrazin-6-yl)carbonyl]butanedioate (28mg, 0.062mmol) in CH 2 Cl 2

(330pL) at RT. The reaction mixture was heated to 35°C and stirred overnight. The reaction mixture was concentrated under reduced pressure, and the residue was purified by reverse phase HPLC (eluting ACN/H 2 0 gradient with 0.1% TFA modifier, C-18 stationary phase) to afford 4- (2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)-4-oxobutanoic acid. LCMS (C I2 H I3 N 2 0 5 S) (ES, m/z): 297 [M+H] + . X H NMR (500 MHz, DMSO-ri 6 ) d 12.21 (br s, 1H), 8.32 (s, 1H), 4.04 (s, 3H), 4.00 (s, 3H), 3.30 (t, =6.3Hz, 2H), 2.60 (t, =6.2Hz, 2H).

Example 17: (R or V)-4- / |pyrazin-6-yl)-2-ethyl-4-oxobutanoic

acid

CS 2 CO 3 (l73mg, 0.532mmol and methyl 2-bromobutyrate (75pL, 0.65mmol) were added to a stirred mixture of /er/-butyl 3-(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)-3- oxopropanoate (Preparation 2) (90mg, 0.27mmol) in DMF (l.3mL) at RT. The reaction mixture was stirred at RT for 3 hours, and then diluted with Et 2 0 and H 2 0. The organic layers were combined, washed with brine, dried over Na 2 S0 4 , filtered, and concentrated under reduced pressure to afford l-te/7-butyl 4-methyl 2-[(2,3-dimethoxythieno[2,3-Z>]pyrazin-6-yl)carbonyl]-3- ethylbutanedioate, which was used without purification. LCMS (C 2 oH 27 N 2 0 7 S-C 4 H 8 ) (ES, m/z): 383 [M+H-/Bu] + .

A mixture of 1 -tert-butyl 4-methyl 2-|(2.3-dimetho\ythieno| 2.3-6 |pyra/in-6-yl) carbonyl] -3 -ethylbutanedioate (l89mg, 0.205mmol) and TFA (2.0mL) was stirred at 65°C for 1 hour. The reaction mixture was then cooled to RT, diluted with CH2CI2, and concentrated under reduced pressure to afford methyl 4-(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)-2-ethyl-4- oxobutanoate that was used without purification. LCMS (C15H19N2O5S) (ES, m/z): 339 [M+H] + .

LiOH H 2 0 (K mg, 2.46mmol) and H 2 0 (5l3pL) were added to a stirred mixture of methyl 4-(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)-2-ethyl-4-oxobuta noate (l36mg, 0.205 mmol) in THF (l.OmL) and MeOH (0.5mL). The reaction mixture was stirred and heated to 40°C for 1 hour. The reaction mixture was then cooled to RT and quenched with HC1 (2N, 0.9mL, l.8mmol) to pH ~ 4. The reaction mixture was concentrated under reduced pressure.

The residue was purified by reverse phase HPLC (eluting ACN/H 2 0 with 0.1% TFA modifier, C-18 stationary phase) to afford 4-(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)-2-ethyl-4- oxobutanoic acid as a mixture of enantiomers. The racemic mixture was resolved by Chiral-SFC (CHIRACEL OJ-H (250mmx2lmm), 20% MeOH (with 0.25% DMEA) in C0 2 ) to afford two compounds with retention times of 2.3 min and 2.8 min. Concentration of the first eluting peak afforded ( R or 5')-4-(2.3-dimetho\ythieno|2.3-b|pyrazin-6-yl)-2-ethyl-4-o\o butanoic acid.

LCMS (C14H17N2O5S) (ES, m/z): 325 [M+H] + . X H NMR (500 MHz, DMSO-ri 6 ) d 11.91 (br s, 1H), 8.35 (s, 1H), 4.03 (s, 3H), 4.00 (s, 3H), 3.45 (dd, =l7.5Hz, 9.6Hz, 1H), 3.10 (dd,

.7=17.0Hz, 3.5Hz, 1H), 2.86-2.75 (m, 1H), 1.67-1.57 (m, 2H), 0.92 (t, =7.0Hz, 3H).

Example 18: ( R or V)-4-(2,3- /ilnyrazin-6-yl)-2-methyl-4-oxobutanoic

acid

2-bromopropionic acid /er/-butyl ester (58pL, 0.35mmol) was added to a stirred solution of /e/V-butyl 3-(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)-3-oxopropanoate (59mg,

0. l7mmol) and Cs 2 C0 3 (1 l4mg, 0.349mmol) in DMF (0.9mL) at RT. The reaction mixture was stirred at RT for 3 hours, and then diluted with Et 2 0 and H 2 0. The organic layer was separated, washed with brine, dried over Na 2 S0 4 , filtered, and concentrated under reduced pressure to afford di-/cT/-butyl 2-[(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)carbonyl]-3-methy lbutanedioate, which was used without purification. LCMS (C 22 H 3i N 2 0 7 S-C 8 Hi 6 ) (ES, m/z): 355 [M+H-/Bu- /Bu] + .

A mixture of di-te/7-butyl 2-[(2,3-dimethoxythieno[2,3-b]pyrazin-6-yl)carbonyl]-

3-methylbutanedioate (50mg, O. l lmmol) and TFA (l.OmL) was stirred at 75°C for 1 hour. The reaction mixture was then cooled to RT, diluted with CH 2 Cl 2 , and concentrated under reduced pressure. The residue was purified by reverse phase HPLC (eluting ACN/H 2 0 with 0.1% TFA modifier, C-18 stationary phase) to afford 4-(2,3-dimethoxythieno[2,3-Z>]pyrazin-6-yl)-2-methyl-

4-oxobutanoic acid as a mixture of isomers. The racemic mixture was resolved by Chiral-SFC (Lux-4 (250mmx2lmm), 35% MeOH (with 0.25% DMEA) in C0 2 ) to afford two products with retention times of 3.1 min and 5.1 min. The second eluting peak was concentrated under reduced pressure to afford ( R or A)-4-(2,3-dimethoxythieno[2,3-Z>]pyrazin-6-yl)-2-methyl-4 -oxobutanoic acid. LCMS (C I3 H I5 N 2 0 5 S) (ES, m/z): 311 [M+H] + . 1H NMR (500 MHz, DMSO-ri 6 ) d 11.79 (br s, 1H), 8.30 (s, 1H), 4.03 (s, 3H), 4.00 (s, 3H), 3.44 (dd, =l7.4Hz, 8.3Hz, 1H), 3.07 (dd,

.7=17.0Hz, 3.5Hz, 1H), 2.93-2.81 (m, 1H), 1.17 (d, =6.8Hz, 3H).

Example 19: (A)-4-(5,6-Dimethoxythiazolo[4,5-blpyridin-2-yl)-2-methyl-4- oxobutanoic acid

Step 1: Methyl 2-((5, 6-dimethoxypyridin-2-yl)amino)-2-oxoacetate

A mixture of 5,6-dimethoxypyridin-2-amine (500mg, 3.24mmol), N-ethyl-N- isopropylpropan-2-amine (0.86lmL, 4.86mmol), and CH2CI2 (20 mL) was cooled to 0°C and stirred. Methyl 2-chloro-2-oxoacetate (0.36mL, 3.9mmol) was added dropwise to the reaction mixture over a period of 5 min. Aq NaHCCb (saturated, 2mL) was added to the reaction mixture, and the mixture was extracted with DCM (2x30mL). The organic layers were combined, dried over Na2S0 4 , filtered, and concentrated under reduced pressure to afford methyl 2-((5,6-dimethoxypyridin-2-yl)amino)-2-oxoacetate, which was used without purification. 'H NMR (499 MHz, CDCl 3 ) d 9.11 (s, 1H), 7.78 (d, =8.3Hz, 1H), 7.13 (d, =8.4Hz, 1H), 4.00 (s, 3H), 3.99 (s, 3H), 3.89 (s, 3H).

Step 2: Methyl 2-((5, 6-dimethoxypyridin-2-yl)amino)-2-thioxoacetate

Lawesson's reagent (7l5mg, l.77mmol) was added to a stirred mixture of methyl 2-((5,6-dimethoxypyridin-2-yl)amino)-2-oxoacetate (772mg, 3.2lmmol) in toluene (lOmL). The reaction mixture was heated to 75°C and stirred for 60 hours. The mixture was cooled to RT and filtered. The collected materials were washed with DCM, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in DCM) to afford methyl 2-((5,6-dimethoxypyridin-2-yl)amino)-2-thioxoacetate. 'H NMR (499 MHz, CDCI 3 ) d 10.86 (s, 1H), 8.82 (d, =8.4Hz, 1H), 7.14 (d, =8.4Hz, 1H), 4.02 (s, 6H), 3.93 (s, 3H).

Step 3: 5, 6-Dimethoxythiazolo[4,5-b]pwidine-2-carboxylic acid

„0

KOH (2N, 4 mL, 8mmol) was added to a mixture of methyl 2-((5,6-dimethoxy- pyridin-2-yl)amino)-2-thioxoacetate (300mg, L l7mmol) in CH2CI2 (5mL). The mixture was stirred for 10 min. The reaction mixture was partially concentrated under reduced pressure. A solution of potassium ferricyanide(III) hydrate (l.22g, 3.5lmmol) in H 2 0 (8mL) was added to the reaction mixture, and the mixture was stirred vigorously for 10 min. The reaction mixture was diluted with H 2 0 (40mL), acidified to pH 2.6 with aq HC1 (2N), stirred for 10 min, and filtered. The collected materials were washed with H 2 0 (3x5 mL), ACN (2x3mL), and Et 2 0 (2x10 mL). The washed materials were then dried under reduced pressure to afford 5,6- dimethoxythiazolo[4,5-b]pyridine-2-carboxylic acid. 'H NMR (499 MHz, DMSO-rir,) d 8.13 (s, 1H), 3.99 (s, 3H), 3.90 (s, 3H).

Step 4: 5 6-Dimethoxythiazolo[4 5-blpyridine-2-carbonyl chloride

(COCl) 2 (0. l58mL, 1.81 mmol) was added dropwise over a period of 5 min to a stirred mixture of 5,6-dimethoxythiazolo[4,5-b]pyridine-2-carboxylic acid (207mg, 0.860mmol) and DMF (0.0l3ml, O. l7mmol) in CH 2 Cl 2 (2 mL) at 0°C. After 15 min, the reaction mixture was warmed to RT and then stirred for an additional 30 min. The reaction mixture was concentrated under reduced pressure to afford 5,6-dimethoxythiazolo[4,5-b]pyridine-2-carbonyl chloride, which was used without purification.

A mixture of CuCl (80mg, 0.81 mmol) in THF (0.6mL) was sparged with N 2 . The mixture was stirred and cooled to 0°C. (i?)-(3-methoxy-2-methyl-3-oxopropyl)zinc(II) bromide (0.50M in THF, 8. lmL, 4. lmmol) was added dropwise to the reaction mixture over a period of 2 min. The reaction mixture was stirred for 10 min at 0°C. A solution of 5,6-dimethoxythiazolo [4,5-b]pyridine-2-carbonyl chloride (2l0mg, 0.8l2mmol) in degassed NMP (4mL) was then added dropwise over a period of 10 min to the reaction mixture. The reaction mixture was stirred for an additional 10 min. The reaction mixture was quenched by the dropwise addition of concentrated aq NH 3 (4mL), diluted with EtOAc (30mL), and washed with H 2 0 (2x40 mL). The organic layer was dried over Na 2 S0 4 , filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluting EtOAc in Hex) to afford (A)-methyl 4-(5,6-dimethoxythiazolo[4,5-b]pyridin-2-yl)-2-methyl-4-oxob utanoate. LCMS (C |4 H | -N 2 0 3 S) (ES, m/z): 325 (M+H) + . X H NMR (499 MHz, CDCf) d 7.56 (s, 1H), 4.21 (s, 3H), 4.02 (s, 3H), 3.81 (dd, J=l8.4Hz, 8.6Hz, 1H), 3.72 (s, 3H), 3.41 (dd, J=l8.4Hz, 5.2Hz, 1H), 3.21-3.14 (m,

1H), 1.33 (d, J=7.2Hz, 3H).

Step 6: ( S)-4-(5, 6-Dimethoxythiazolo[4,5-blpyridin-2-yl)-2-methyl-4-oxobutano ic acid

KOH (0.50M in H 2 0, 0.3lmL, 0.l5mmol) was added dropwise to a stirred mixture of fY)- methyl 4-(5,6-dimethoxythiazolo[4,5-b]pyridin-2-yl)-2-methyl-4-oxob utanoate (24.8mg, 0.0760mmol) in 2-propanol (0.5mL) at RT. After 15 min, the reaction mixture was acidified with HC1 (1N) to pH ~ 2. After stirring for an additional 5 min, the reaction mixture was filtered, and the collected materials were washed with H 2 0 (3x2mL). The washed materials were dissolved in DMSO (2mL) and purified by reverse phase HPLC (eluting ACN/H 2 0 with 0.1% TFA) to afford (<S)-4-(5,6-dimethoxythiazolo[4,5-b]pyridin-2-yl)-2-methy l-4-oxobutanoic acid. LCMS (C I3 H I5 N 2 0 5 S) (ES, m/z): 311 (M+H) + . X H NMR (499 MHz, DMSO-ri 6 ) d 12.30 (s, 1H), 8.16 (s, 1H), 4.01 (s, 3H), 3.92 (s, 3H), 3.60 (dd, =l7.9Hz, 8.8Hz, 1H), 3.21 (dd, =l7.9Hz, 5.0Hz, 1H), 3.01-2.94 (m, 1H), 1.22 (d, =7.2Hz, 3H).

BIOLOGICAL EVALUATION

The individual compounds described in the Examples herein are defined as STING agonists by (i) binding to the STING protein as evidenced by a reduction in binding of tritiated cGAMP ligand to the STING protein by at least 20% at 20uM (concentration of compound being tested) in a STING Biochemical [3H]cGAMP Competition Assay and/or (ii) demonstrating interferon production with a 6% or greater induction of IFN-b secretion at 30uM in the ΊΉR1 cell assay (where induction caused by cGAMP at 30uM was set at 100%). -cGAMP Synthesis

2.3mL of buffer solution containing 80mM TrisCl, 200mM MgCl 2 , and 20mM NaCl followed by 0.32mL of a lOmM aq solution of GTP was added to a plastic 50mL AMICON tube. A solution of [ 3 H]ATP (2lCi/mmol, 45mCi) in 0.5mL H 2 0 was then added followed by lmL of a lmg/mL solution of DNA (Herring testes activator DNA, Sigma, #D6898) and 53uL of a 47mM solution of cGAS enzyme. Additional H 2 0 was added to bring the total volume to lOmL.

The reaction was stirred for 2h at 37°C and then added directly to an Amicon Ultra- 15 10K centrifuge tube and spun for lh at 4,000g. The collected solution was then purified on a semi-prep Mono Q column using the following mobile phases:

A: 0.05M TrisCl pH 8.5 adjusted with 1M NaOH B: 0.05M TrisCl, 0.5M NaCl pH 8.5 adjusted with 1M NaOH

Gradient: 100% A for 5min followed by a linear gradient to 50:50 (A:B) over 25min, 3mL/min, 254nm.

The collected product fractions were pooled and adjusted to a total volume of 30mL with buffer A. A total yield of l5.5mCi of [ 3 H]cGAMP was isolated at a radiochemical purity of 98.0% at a specific activity of 2l.5Ci/mmol. cGAS Enzyme

A recombinant DNA vector was chemically synthesized to express the truncated human cGAS enzyme (residues 161-522). To aid in expression and purification, the amino terminus contains a hexahistidine tag, SUMO tag and TEV cleavage site. The recombinant enzyme was overexpressed in ROSETTA™ 2(DE3) Single Competent Cells (Novagen). Affinity purification was carried out using HIS-Select HF Nickel Affinity Gel (Sigma) followed by size exclusion chromatography using a Hi-Load 26/60 SUPERDEX200 prep grade column (GE Healthcare). Fractions were pooled, concentrated, flash-frozen in liquid nitrogen and stored at -80°C until needed.

3 H-cGAMP filtration binding assay (11LO STING)

The ability of compounds to bind STING is quantified by their ability to compete with tritiated cGAMP ligand for human STING receptor membrane using a radioactive filter binding assay. The binding assay employs STING receptor obtained from Trichoplusia ni cell membranes ( T.ni ; Expression Systems, cat # 94-002F, www. exjjressionsystems. com)

overexpressing full-length HAQ STING and tritiated cGAMP ligand.

The basic HAQ STING filtration assay protocol is as follows:

The compounds were serially titrated by the Hamilton STARPlus CORE in a 96- well plate (Greiner, # 651201) using a 1 :3 ten-point dose response format. After compound preparation, a 2.2ug/ml working concentration of STING membrane (SEQ. ID. No. 1) was prepared by diluting concentrated membrane into assay buffer (lx PBS; Invitrogen #

SH30028.02) and douncing 7x using a manual tissue homogenizer (Wheaton, # 357546). l48uL of prepared membrane was then manually added to each well of a 96-well deep-well polypropylene plate (Fisher Scientific, # 12-566-121). Following membrane addition, 2uL of either titrated test compound, DMSO control (Sigma # 276855), or cold cGAMP control was added to the appropriate wells using a BIOMEK FX. Compound and membrane then preincubated for 60min at RT to allow compound binding to equilibrate. Following equilibration, 8nM of [ 3 H] c-GAMP ligand was prepared by diluting into assay buffer, and 50uL of this working stock was then manually added to each well of the assay plate. Plates were then incubated at RT for 60min, and the contents of each assay plate were then filtered through a 96-well GF/B filter plate (PerkinElmer, # 6005250) using a TOMTEC MACH III Cell Harvester equipped with 20mM HEPES buffer (Fisher Scientific, # BP299500). The filter plates were then dried at 55°C for 30min using a pressurized oven before 30uL of ULTIMA GOLD F scintillate was added to each well. Tritium levels for each reaction well were then measured using a PerkinElmer TopCount plate reader.

After normalization to controls, the percent activity for each compound concentration was calculated by measuring the amount of remaining radioactivity. The plot of percent activity versus the log of compound concentration was fit with a 4-parameter dose response equation to calculate EC 50 values.

The final reaction conditions were:

Component Volume (uL) Final Concentration

STING membrane 148 l.5ug/ml

3 H-CGAMP 50 2.0nM

Low Control (cold cGAMP) 2 lOuM

Test compound/DMSO 2 lOuM

Compound concentrations tested were 20.000, 637.00, 2.200, 0.740, 0.247, 0.082,

0.027, 0.009, 0.003, and O.OOImM with 1.0% residual DMSO.

Full-Length STING (HAQ) Virus Generation

STING virus was generated using an insect cell baculovirus system. Spodoptera frugiperda Sf21 cells (Kempbio, Inc.) were diluted to 5e5 cells/ml in Sf-900II SFM media

(LifeTechnologies # 10902088) without antibiotics. The cell suspension was added to each well of a treated 6-well plate (2mL per well, le6 cells total), and the cells were allowed to adhere for at least 30min. Meanwhile, a lmL co-transfection mix was assembled by combining 500ng of HAQ STING [STING(l-379)R7lH,G230A,H232R,R293Q-GG-AviTag-GS-HRV3C- HIS8/pBACl] DNA (Genewiz custom synthesis) with lmL Sf-900II SFM media containing lOpL Cellfectin® II Reagent (Invitrogen # 10362100) and lOOng viral backbone BestBac 2.0, v- cath/chiA Deleted Linearized Baculovirus DNA (Expression Systems # 91-002). The transfection mixtures were allowed to incubate for 30min. After incubation, media was gently removed from the adhered cells in the 6-well plate, the lmL transfection mixtures were added (lmL per well), and the plate was placed in a humidified incubator at 27°C. The following day, lmL Sf-900II SFM media (no antibiotics) was added to each well of the 6-well plate. After media addition, the cells were allowed to incubate with DNA (SEQ. ID. No. 2) at 27°C for 5-7 days to generate the P0 viral stock. To generate Pl viral stocks, 0.5mL of P0 viral supernatant was added to 50mL uninfected Sf21 cells (seeded the day prior to infection at a density of 5x10 5 cells/mL to allow for one overnight doubling) in Sf-900II SFM media containing 5pg/mL gentamicin (Invitrogen #15710072). The infected cells were then incubated at 27°C for 3days while shaking at l lOrpm (ATR Biotech Multitron Infors HT #AJl l8). On day 3, Pl cultures were counted using a ViCell XR (Beckman Coulter Life Sciences # 383556) to confirm infection had occurred (cell size >3pm larger than uninfected cells and viability approximately 85-95%). Cultures were harvested in 50mL conical tubes and centrifuged at 2000xg for lOmin at 4°C. The Pl viral supernatants were poured off into clean 50ml centrifuge tubes, and the remaining Pl cell pellets were used to generate Baculovirus Infected Insect Cells (BIICs). Cryopreservation media containing Sf-900II SFM media with 10% heat inactivated FBS, 10% DMSO (Sigma #D2650), and 5pg/ml gentamicin was prepared and sterilized through 0.22mM filter immediately prior to use. Pl cell pellets were resuspended to a density of 2e7 cells/ml and aliquoted into cryovials (lmL per vial). Cryovials were placed in MR. FROSTY™ cell freezers O/N at -80°C and transferred to liquid nitrogen for long term storage the following day. To generate P2 viral stock, 0.5mL of the Pl viral supernatant was added to 50mL uninfected Sf21 cells (seeded the day prior to infection at a density of 5x10 5 cells/mL to allow for one overnight doubling) in Sf- 900II SFM media containing 5pg/mL gentamicin. These cells were incubated at 27°C for 3days while shaking at 1 lOrpm before harvesting P2 stock with centrifugation at 2000xg for lOmin at 4°C. The P2 viral supernatants were poured off and discarded, while the P2 cell pellets were used to generate P2 BIICs following the same protocol described above. The baculovirus generation protocol has been validated to consistently produce P1/P2 BIICs with titers of 2e9 pfu/mL (2e7 cells/mLxlOO pfu/cell).

Full-Length STING (HAQ) Expression

To generate STING membranes, P1/P2 BIICs were amplified overnight by adding thawed BIICs to Sf21 cells seeded at a density of L0xl0 6 cells/mL. The volume of BIIC used to infect the culture was calculated using an assumed BIIC titer of 2e9 pfu/ml to achieve an MOI of 10 in the overnight amplification. After culturing overnight, the cells were counted on a ViCell XR to confirm infection had occurred (cell size >3 pm larger than uninfected cells and viability approximately 80-90%). The volume of infected Sf21 cells from the overnight amplification used to infect the large-scale expression of Trichoplusia ni ( T.ni ; Expression Systems, cat # 94- 002F, www. onsvstems. com) seeded at a density of 1.0x10 6 in cell media (ESF921 SFM

containing 5pg/mL gentamicin) at MOI=2.0 was calculated based on (100 pfu/infected Sf2I cell). The cells were allowed to express for 48h at 27°C before harvesting the cell pellet, by centrifugation at 3,400xg for lOmin at 4°C. T. ni cells were counted on a ViCell XR to confirm infection had occurred (cell size >3 pm larger than uninfected cells and viability approximately 80-90%) prior to harvest.

Full-Length STING (HAQ) Membrane Generation

Buffer stock reagents:

1) 1M HEPES pH 7.5, Teknova, Cat#Hl035

2) 5M NaCl, Sigma Aldrich, Cat#S5l50-lL

3) KC1, Sigma Aldrich, Cat#3l9309-500ML

4) Complete EDTA-free protease inhibitor tablets, Roche Diagnostics, Cat#l l87358000l

5) Benzonase, Universal Nuclease, Pierce, Cat# 88702

Lysis buffer [25mM HEPES pH 7.5, lOmM MgCl 2 , 20mM KC1, (Benzonase 1 :5000, Complete Protease Inhibitor tab/50mL)] was added to the pellet of cells expressing full- length STING (HAQ) prepared above at 5mL Lysis buffer per g of cell pellet. The pellet was resuspended and dounced twenty times using a Wheaton Dounce Homogenizer to disrupt the cell membrane. Homogenized lysate was then passed through the EMULSIFLEX-C5 microfluidizer at a pressure close to 5000PSI. The resuspended pellet was centrifuged at 36,000rpm (l00,000xg) in a 45Ti rotor ultra-high speed centrifuge for 45min, 4°C. The supernatant was removed. The pellet then was resuspended in wash buffer [(25mM HEPES pH7.5, lmM MgCT. 20mM KC1, 1M NaCl (Complete Protease Inhibitor tab/50mL)] at a volume of 50mL pellet/centrifuge tube. The pellet/wash buffer mixture was then homogenized, using a glass homogenizer on ice (20 strokes), followed by centrifugation at 36,000rpm for 45min at 4°C. The supernatant was removed. The wash step was repeated once more. The resulting membrane was resuspended in 20mM HEPES pH 7.5, 500mM NaCl, 10% glycerol, EDTA-free Protease Inhibitors

(ltablet/50mL). The protein concentration was measured by Bradford assay (Bio-Rad Protein Assay, Cat# 500-0006), and protein enrichment was determined by SDS-PAGE and confirmed by Western blot. The resuspended membranes were stored at -80°C.

Full-Length HAQ STING [STING(l-379)R71HG230A,H232RR293Q-GG-AviTag-GS-HRV3C- HIS8J Amino Acid Sequence:

MPHSSLHPSIPCPRGHGAQKAALVLLSACLVTLWGLGEPPEHTLRYLVLHLASLQLGLL LNGVCSLAEELHHIHSRYRGS YWRTVRACLGCPLRRGALLLLSIYFYY SLPNAV GPPFT WML ALLGLS QALNILLGLKGLAP AEIS AV CEKGNFNV AHGL AW S YYIGYLRLILPELQ A RIRTYNQHYNNLLRGAVSQRLYILLPLDCGVPDNLSMADPNIRFLDKLPQQTADRAGIK DRV Y SNSI YELLEN GQRAGT C VLEY ATPLQTLF AMS Q Y S Q AGF S REDRLEQ AKLF C QTL EDIL AD APES QNNCRLIAY QEP ADDS SF SLS QEVLRHLRQEEKEEVTV GSLKTS AVP STST MS QEPELLI S GMEKPLPLRTDF S GGGLNDIFE AQKIEWHEGS LEVLF QGPHHHHHHHH

(SEQ. ID. No. 1)

Full-length HAQ [STING(1-379)R71H G230A,H232RR293Q-GG-AviTag-GS-HRV3C- HIS8/pBACl ] Plasmid DNA Sequence:

GGAACGGCTCCGCCCACTATTAATGAAATTAAAAATTCCAATTTTAAAAAACGCAG

CAAGAGAAACATTTGTATGAAAGAATGCGTAGAAGGAAAGAAAAATGTCGTCGAC

ATGCTGAACAACAAGATTAATATGCCTCCGTGTATAAAAAAAATATTGAACGATTTG

AAAGAAAACAATGTACCGCGCGGCGGTATGTACAGGAAGAGGTTTATACTAAACTG

TTACATTGCAAACGTGGTTTCGTGTGCCAAGTGTGAAAACCGATGTTTAATCAAGGC

TCTGACGCATTTCTACAACCACGACTCCAAGTGTGTGGGTGAAGTCATGCATCTTTT

AATCAAATCCCAAGATGTGTATAAACCACCAAACTGCCAAAAAATGAAAACTGTCG

ACAAGCTCTGTCCGTTTGCTGGCAACTGCAAGGGTCTCAATCCTATTTGTAATTATT G

AATAATAAAACAATTATAAATGCTAAATTTGTTTTTTATTAACGATACAAACCAAAC

GCAACAAGAACATTTGTAGTATTATCTATAATTGAAAACGCGTAGTTATAATCGCTG

AGGTAATATTTAAAATCATTTTCAAATGATTCACAGTTAATTTGCGACAATATAATT

TTATTTTCACATAAACTAGACGCCTTGTCGTCTTCTTCTTCGTATTCCTTCTCTTTT TC

ATTTTTCTCTTCATAAAAATTAACATAGTTATTATCGTATCCATATATGTATCTA TCG

TATAGAGTAAATTTTTTGTTGTCATAAATATATATGTCTTTTTTAATGGGGTGTATA G

TACCGCTGCGCATAGTTTTTCTGTAATTTACAACAGTGCTATTTTCTGGTAGTTCTT C

GGAGTGTGTTGCTTTAATTATTAAATTTATATAATCAATGAATTTGGGATCGTCGGT T

TTGTACAATATGTTGCCGGCATAGTACGCAGCTTCTTCTAGTTCAATTACACCATTT T TTAGCAGCACCGGATTAACATAACTTTCCAAAATGTTGTACGAACCGTTAAACAAAA

ACAGTTCACCTCCCTTTTCTATACTATTGTCTGCGAGCAGTTGTTTGTTGTTAAAAA T

AACAGCCATTGTAATGAGACGCACAAACTAATATCACAAACTGGAAATGTCTATCA

ATATATAGTTGCTGATCAGATCTGATCATGGAGATAATTAAAATGATAACCATCTCG

CAAATAAATAAGTATTTTACTGTTTTCGTAACAGTTTTGTAATAAAAAAACCTATAA

ATATAGGATCCATGCCCCACTCCAGCCTGCATCCATCCATCCCGTGTCCCAGGGGTC

ACGGGGCCCAGAAGGCAGCCTTGGTTCTGCTGAGTGCCTGCCTGGTGACCCTTTGGG

GGCTAGGAGAGCCACCAGAGCACACTCTCCGGTACCTGGTGCTCCACCTAGCCTCCC

TGCAGCTGGGACTGCTGTTAAACGGGGTCTGCAGCCTGGCTGAGGAGCTGCACCAC

ATCCACTCCAGGTACCGGGGCAGCTACTGGAGGACTGTGCGGGCCTGCCTGGGCTG

CCCCCTCCGCCGTGGGGCCCTGTTGCTGCTGTCCATCTATTTCTACTACTCCCTCCC A

AATGCGGTCGGCCCGCCCTTCACTTGGATGCTTGCCCTCCTGGGCCTCTCGCAGGCA

CTGAACATCCTCCTGGGCCTCAAGGGCCTGGCCCCAGCTGAGATCTCTGCAGTGTGT

GAAAAAGGGAATTTCAACGTGGCCCATGGGCTGGCATGGTCATATTACATCGGATA

TCTGCGGCTGATCCTGCCAGAGCTCCAGGCCCGGATTCGAACTTACAATCAGCATTA

CAACAACCTGCTACGGGGTGCAGTGAGCCAGCGGCTGTATATTCTCCTCCCATTGGA

CTGTGGGGTGCCTGATAACCTGAGTATGGCTGACCCCAACATTCGCTTCCTGGATAA

ACTGCCCCAGCAGACCGCTGACCGTGCTGGCATCAAGGATCGGGTTTACAGCAACA

GCATCTATGAGCTTCTGGAGAACGGGCAGCGGGCGGGCACCTGTGTCCTGGAGTAC

GCCACCCCCTTGCAGACTTTGTTTGCCATGTCACAATACAGTCAAGCTGGCTTTAGC

CGGGAGGATAGGCTTGAGCAGGCCAAACTCTTCTGCCAGACACTTGAGGACATCCT

GGCAGATGCCCCTGAGTCTCAGAACAACTGCCGCCTCATTGCCTACCAGGAACCTGC

AGATGACAGCAGCTTCTCGCTGTCCCAGGAGGTTCTCCGGCACCTGCGGCAGGAGG

AAAAGGAAGAGGTT ACT GT GGGC AGCTT GAAGAC CT C AGC GGTGC CC AGT AC CTCC

ACGATGTCCCAAGAGCCTGAGCTCCTCATCAGTGGAATGGAAAAGCCCCTCCCTCTC

CGCACGGATTTCTCTGGCGGTGGCCTGAACGACATCTTCGAAGCCCAGAAAATCGA

ATGGCATGAAGGCAGCCTGGAAGTGCTGTTCCAGGGCCCACACCACCATCATCACC

ATCACCATTAATGAGCGGCCGCACTCGAGCACCACCACCACCACCACTAACCTAGG

TAGCTGAGCGCATGCAAGCTGATCCGGGTTATTAGTACATTTATTAAGCGCTAGATT

CTGTGCGTTGTTGATTTACAGACAATTGTTGTACGTATTTTAATAATTCATTAAATT T

ATAATCTTTAGGGTGGTATGTTAGAGCGAAAATCAAATGATTTTCAGCGTCTTTATA

TCTGAATTTAAATATTAAATCCTCAATAGATTTGTAAAATAGGTTTCGATTAGTTTC A

AACAAGGGTTGTTTTTCCGAACCGATGGCTGGACTATCTAATGGATTTTCGCTCAAC GCCACAAAACTTGCCAAATCTTGTAGCAGCAATCTAGCTTTGTCGATATTCGTTTGT

GTTTTGTTTTGTAATAAAGGTTCGACGTCGTTCAAAATATTATGCGCTTTTGTATTT C

TTTCATCACTGTCGTTAGTGTACAATTGACTCGACGTAAACACGTTAAATAGAGCTT

GGACATATTTAACATCGGGCGTGTTAGCTTTATTAGGCCGATTATCGTCGTCGTCCC

AACCCTCGTCGTTAGAAGTTGCTTCCGAAGACGATTTTGCCATAGCCACACGACGCC

TATTAATTGTGTCGGCTAACACGTCCGCGATCAAATTTGTAGTTGAGCTTTTTGGAA T

TATTTCTGATTGCGGGCGTTTTTGGGCGGGTTTCAATCTAACTGTGCCCGATTTTAA T

TCAGACAACACGTTAGAAAGCGATGGTGCAGGCGGTGGTAACATTTCAGACGGCAA

ATCTACTAATGGCGGCGGTGGTGGAGCTGATGATAAATCTACCATCGGTGGAGGCG

CAGGCGGGGCTGGCGGCGGAGGCGGAGGCGGAGGTGGTGGCGGTGATGCAGACGG

CGGTTTAGGCTCAAATGTCTCTTTAGGCAACACAGTCGGCACCTCAACTATTGTACT

GGTTTCGGGCGCCGTTTTTGGTTTGACCGGTCTGAGACGAGTGCGATTTTTTTCGTT T

CTAATAGCTTCCAACAATTGTTGTCTGTCGTCTAAAGGTGCAGCGGGTTGAGGTTCC

GTCGGCATTGGTGGAGCGGGCGGCAATTCAGACATCGATGGTGGTGGTGGTGGTGG

AGGCGCTGGAATGTTAGGCACGGGAGAAGGTGGTGGCGGCGGTGCCGCCGGTATAA

TTTGTTCTGGTTTAGTTTGTTCGCGCACGATTGTGGGCACCGGCGCAGGCGCCGCTG

GCTGCACAACGGAAGGTCGTCTGCTTCGAGGCAGCGCTTGGGGTGGTGGCAATTCA

ATATTATAATTGGAATACAAATCGTAAAAATCTGCTATAAGCATTGTAATTTCGCTA

TCGTTTACCGTGCCGATATTTAACAACCGCTCAATGTAAGCAATTGTATTGTAAAGA

GATTGTCTCAAGCTCGGATCGATCCCGCACGCCGATAACAAGCCTTTTCATTTTTAC T

ACAGCATTGTAGTGGCGAGACACTTCGCTGTCGTCGAGGTTTAAACGCTTCCTCGCT

CACTGACTCGCTGCGCTCGGTCGTTCGGCTGCGGCGAGCGGTATCAGCTCACTCAAA

GGCGGTAATACGGTTATCCACAGAATCAGGGGATAACGCAGGAAAGAACATGTGAG

CAAAAGGCCAGCAAAAGGCCAGGAACCGTAAAAAGGCCGCGTTGCTGGCGTTTTTC

CATAGGCTCCGCCCCCCTGACGAGCATCACAAAAATCGACGCTCAAGTCAGAGGTG

GCGAAACCCGACAGGACTATAAAGATACCAGGCGTTTCCCCCTGGAAGCTCCCTCG

TGCGCTCTCCTGTTCCGACCCTGCCGCTTACCGGATACCTGTCCGCCTTTCTCCCTT C

GGGAAGCGTGGCGCTTTCTCATAGCTCACGCTGTAGGTATCTCAGTTCGGTGTAGGT

CGTTCGCTCCAAGCTGGGCTGTGTGCACGAACCCCCCGTTCAGCCCGACCGCTGCGC

CTTATCCGGTAACTATCGTCTTGAGTCCAACCCGGTAAGACACGACTTATCGCCACT

GGCAGCAGCCACTGGTAACAGGATTAGCAGAGCGAGGTATGTAGGCGGTGCTACAG

AGTT CTTGAAGTGGTGGCCT AACT AC GGCT AC ACT AGAAGGAC AGT ATTT GGT AT CT

GCGCTCTGCTGAAGCCAGTTACCTTCGGAAAAAGAGTTGGTAGCTCTTGATCCGGCA AACAAACCACCGCTGGTAGCGGTGGTTTTTTTGTTTGCAAGCAGCAGATTACGCGCA

GAAAAAAAGGATCTCAAGAAGATCCTTTGATCTTTTCTACGGGGTCTGACGCTCAGT

GGAACGAAAACTCACGTTAAGGGATTTTGGTCATGAGATTATCAAAAAGGATCTTC

ACCTAGATCCTTTTAAATTAAAAATGAAGTTTTAAATCAATCTAAAGTATATATGAG

TAAACTTGGTCTGACAGTTACCAATGCTTAATCAGTGAGGCACCTATCTCAGCGATC

TGTCTATTTCGTTCATCCATAGTTGCCTGACTCCCCGTCGTGTAGATAACTACGATA C

GGGAGGGCTTACCATCTGGCCCCAGTGCTGCAATGATACCGCGAGACCCACGCTCA

CCGGCTCCAGATTTATCAGCAATAAACCAGCCAGCCGGAAGGGCCGAGCGCAGAAG

TGGTCCTGCAACTTTATCCGCCTCCATCCAGTCTATTAATTGTTGCCGGGAAGCTAG

AGTAAGTAGTTCGCCAGTTAATAGTTTGCGCAACGTTGTTGCCATTGCTACAGGCAT

CGTGGTGTCACGCTCGTCGTTTGGTATGGCTTCATTCAGCTCCGGTTCCCAACGATC A

AGGCGAGTTACATGATCCCCCATGTTGTGCAAAAAAGCGGTTAGCTCCTTCGGTCCT

CCGATCGTTGTCAGAAGTAAGTTGGCCGCAGTGTTATCACTCATGGTTATGGCAGCA

CTGCATAATTCTCTTACTGTCATGCCATCCGTAAGATGCTTTTCTGTGACTGGTGAG T

ACTCAACCAAGTCATTCTGAGAATAGTGTATGCGGCGACCGAGTTGCTCTTGCCCGG

CGTCAATACGGGATAATACCGCGCCACATAGCAGAACTTTAAAAGTGCTCATCATTG

GAAAACGTTCTTCGGGGCGAAAACTCTCAAGGATCTTACCGCTGTTGAGATCCAGTT

CGATGTAACCCACTCGTGCACCCAACTGATCTTCAGCATCTTTTACTTTCACCAGCG T

TTCTGGGTGAGCAAAAACAGGAAGGCAAAATGCCGCAAAAAAGGGAATAAGGGCG

ACACGGAAATGTTGAATACTCATACTCTTCCTTTTTCAATATTATTGAAGCATTTAT C

AGGGTTATTGTCTCATGAGCGGATACATATTTGAATGTATTTAGAAAAATAAACAAA

TAGGGGTTCCGCGCACATTTCCCCGAAAAGTGCCACCTGACGCGCCCTGTAGCGGCG

CATTAAGCGCGGCGGGTGTGGTGGTTACGCGCAGCGTGACCGCTACACTTGCCAGC

GCCCTAGCGCCCGCTCCTTTCGCTTTCTTCCCTTCCTTTCTCGCCACGTTCGCCGGC TT

TCCCCGTCAAGCTCTAAATCGGGGGCTCCCTTTAGGGTTCCGATTTAGTGCTTTACG

GCACCTCGACCCCAAAAAACTTGATTAGGGTGATGGTTCACGTAGTGGGCCATCGCC

CTGATAGACGGTTTTTCGCCCTTTGACGTTGGAGTCCACGTTCTTTAATAGTGGACT C

TTGTTCCAAACTGGAACAACACTCAACCCTATCTCGGTCTATTCTTTTGATTTATAA G

GGATTTTGCCGATTTCGGCCTATTGGTTAAAAAATGAGCTGATTTAACAAAAATTTA

ACGCGAATTTTAACAAAATATTAACGTTTACAATTTCCCATTCGCCATTCAGGCTGC

GCAACTGTTGGGAAGGGCGATCGGTGCGGGCCTCTTCGCTATTACGCCA

(SEQ. ID. No. 2) Certain compounds of the disclosure were evaluated in HAQ STING in vitro binding assay as described above. The following table tabulates the biological data for these compounds as EC 50 values.

Table 1: 3 H-cGAMP filtration binding assay for HAQ STING

IFN-b secretion in THP1 cell culture

The ability of compounds to stimulate the secretion of interferon-beta from THP1 cells was measured using a human IFN-b AlphaLISA kit (Perkin Elmer, Cat. No. AL265F). The basic protocol is as follows:

A Labcyte Echo 550 acoustic dispenser was used to transfer l20nL of compound dissolved in DMSO into the wells of an empty, sterile 384-well microplate, (Coming, Cat. No. 3712). THP1 cells (American Type Culture Collection, Cat. No. TIB202) previously frozen in Recovery Medium (Life Technologies, Cat. No. 12648-010) were thawed and immediately diluted 10-fold into 37°C assay medium (RPMI 1640 + L-Glutamine & phenol red, Life Technologies, Cat. No. 11875-085; 0.5% heat inactivated fetal bovine serum, Sigma Aldrich,

Cat. No. F4135; lmM Sodium Pyruvate, Life Technologies, Cat. No. 11360-070; lx non- essential amino acids; Life Technologies, Cat. No. 11140-050). The cell viability and count was ascertained using a Beckman Coulter V-Cell XR cell counter. The cells suspension was centrifuged at 200xg for 5min at RT. Cells were resuspended to a density of 0.8xl0 6 /mL in 37°C assay medium. Subsequent liquid transfers were performed using either a Matrix electronic multichannel pipette or an Agilent Bravo Automated Liquid Handling Platform.

The assay was started by dispensing 40pL of the previously prepared cell suspension into the wells of the plate containing compounds. After 5h incubation at 37°C, 5% CO 2 in a humidified atmosphere, the plate of cells and compounds was centrifuged at 200xg for 5min at RT. From each well, 5pL of supernatant was transferred into corresponding wells of a white 384-well plate (Perkin Elmer, Cat. No. 6005620). To these supernatant-containing wells was added lOpL of 5x Anti -Analyte Acceptor beads (50pg/mL of AlphaLISA HiBlock Buffer) and incubated for 30min at RT while shaking on an orbital plate shaker. To each well was added lOpL of 5x Biotinylated Antibody Anti-analyte (5nM in AlphaLISA HiBlock Buffer) and incubated on an orbital plate shaker for 60min at RT or overnight at 4°C. To each well was added 25pL of 2x SA-Donor beads (80pg/mL in AlphaLISA HiBlock Buffer) and incubated for 30-45min at RT in the dark while shaking on an orbital plate shaker. The plate was then read on a Perkin Elmer Envision (/- cx =680nm. /. cm =570nm). The percent effect of the AlphaLISA signal at each compound concentration was calculated based on 30uM cGAMP positive controls and 0.3% DMSO negative controls. The plot of percent effect versus the log of compound concentration was fit with a 4-parameter concentration response equation to calculate EC 50 values. The test compounds were tested at concentrations 30000, 10000, 3333, 1111, 370.4, 123.4, 41.2, 13.7, 4.6, and l.5nM with 0.3% residual DMSO. The control compound, cGAMP was tested at concentrations 100000, 33333, 11111, 3704, 1235, 412, 137, 46, and 15hM with 0.3% residual DMSO.

Compounds of the disclosure were evaluated for IFN-b secretion in THP1 cell culture as described above. The following table tabulates the biological data for these compounds as percent activation relative to 2’3’-cGAMP at the 30mM concentration.

Table 2: IFN-b secretion in THP1 cell culture (5h)

It will be appreciated that various of the above-discussed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. It also will be appreciated that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art and are also intended to be encompassed by the following claims.