METHODS FOR TREATING HUNTINGTON'S DISEASE

The present description relates to compounds, forms, and pharmaceutical compositions thereof and methods of using such compounds, forms, or compositions thereof for treating or ameliorating Huntington's disease. In particular, the present description relates to substituted monocyclic heteroaryl compounds, forms and pharmaceutical compositions thereof and methods of using such compounds, forms, or compositions thereof for treating or ameliorating

Huntington's disease.

BACKGROUND

Huntington's disease (HD) is a progressive, autosomal dominant neurodegenerative disorder of the brain, having symptoms characterized by involuntary movements, cognitive impairment, and mental deterioration. Death, typically caused by pneumonia or coronary artery disease, usually occurs 13 to 15 years after the onset of symptoms. The prevalence of HD is between three and seven individuals per 100,000 in populations of western European descent. In North America, an estimated 30,000 people have HD, while an additional 200,000 people are at risk of inheriting the disease from an affected parent. The disease is caused by an expansion of uninterrupted trinucleotide CAG repeats in the "mutant" huntingtin (Htt) gene, leading to production of HTT (Htt protein) with an expanded poly-glutamine (polyQ) stretch, also known as a "CAG repeat" sequence. There are no current small molecule therapies targeting the underlying cause of the disease, leaving a high unmet need for medications that can be used for treating or ameliorating HD. Consequently, there remains a need to identify and provide small molecule compounds for treating or ameliorating HD.

All other documents referred to herein are incorporated by reference into the present application as though fully set forth herein.

SUMMARY The present description relates to methods for treating or ameliorating HD in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I): N— N

(I)

wherein W, X, A and B are as defined herein, or forms and compositions thereof.

In particular, the present description relates to a use of a compound of Formula (I) or a form or composition thereof in a method for treating or ameliorating HD in a subject in need thereof comprising, administering an effective amount of the compound or a form or

composition thereof, to the subject.

The present description further relates to the use of a compound of Formula (I) or a form thereof in combination with agents having additive or synergistic activity, thus providing a combination product for the treatment of HD.

DETAILED DESCRIPTION

The present description relates to a method or use of a compound for treating or ameliorating HD in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I :

(I)

or a form thereof, wherein

W is CH=CH or S;

X is CH ₂ , CH(Ci_ ₄ alkyl), C(Ci_ ₄ alkyl) ₂ , CH=CH, O, NR ₅ , or a bond;

A is aryl, heteroaryl, heterocyclyl, or C9_iocycloalkyl,

wherein aryl is selected from phenyl and naphthyl, each optionally substituted with 1, 2, 3, or 4 substituents each selected from Ri,

wherein heteroaryl is a saturated monocyclic, bicyclic or tricyclic ring system having 1, 2, or 3 heteroatom ring members independently selected from N, O, or S, each optionally substituted with 1, 2, 3, 4, or 5 substituents each selected from Ri, wherein heterocyclyl is a saturated or partially unsaturated monocyclic, bicyclic or tricyclic ring system having 1, 2, or 3 heteroatom ring members independently selected from N, O, or S, each optionally substituted with 1, 2, 3, 4, or 5 substituents each selected from R ₂ , and wherein C9_iocycloalkyl is a saturated or partially unsaturated bicyclic ring system optionally substituted with 1, 2, 3, 4, or 5 substituents each selected from R ₂ ;

B is heterocyclyl,

wherein heterocyclyl is a saturated or partially unsaturated monocyclic, bicyclic or polycyclic ring system having 1, 2, or 3 heteroatom ring members independently selected from N, O, or S, each optionally substituted with 1, 2, 3, 4, or 5 substituents each selected from R ₄ ;

Ri is halogen, hydroxyl, cyano, Ci_ ₄ alkyl, halo-Ci_ ₄ alkyl, amino, Ci_ ₄ alkyl- amino,

(Ci_ ₄ alkyl) ₂ -amino, amino-Ci_ ₄ alkyl, Ci_ ₄ alkyl-amino-Ci_ ₄ alkyl,

(Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkyl, amino-carbonyl, Ci_ ₄ alkyl-amino-carbonyl,

(Ci- ₄ alkyl) ₂ -amino-carbonyl, Ci- ₄ alkyl-amino-carbonyl-Ci_ ₄ alkyl, (Ci_ ₄ alkyl) ₂ -amino- carbonyl-Ci- ₄ alkyl, Ci_ ₄ alkyl-carbonyl-amino, Ci- ₄ alkyl-carbonyl-amino-Ci_ ₄ alkyl, hydroxyl-Ci- ₄ alkyl, Ci_ ₄ alkyl-carbonyl, Ci- ₄ alkoxy, halo-Ci- ₄ alkoxy, amino-Ci- ₄ alkoxy, hydroxyl-C i_ ₄ alkoxy, C i_ ₄ alkyl-C i_ ₄ alkoxy, C i_ ₄ alkyl-amino-C i_ ₄ alkoxy,

(Ci- ₄ alkyl) ₂ -amino-Ci_ ₄ alkoxy, Ci- ₄ alkyl-carbonyl-amino-Ci_ ₄ alkoxy, Ci_ ₄ alkoxy- Ci_ ₄ alkoxy, Ci_ ₄ alkoxy-carbonyl, Ci_ ₄ alkoxy-carbonyl-amino, Ci_ ₄ alkoxy-carbonyl- amino-Ci- ₄ alkoxy, C ₂ _ ₄ alkenyl, C ₂ _ ₄ alkenyl-amino-carbonyl, C ₃ _ ₇ cycloalkyl,

C ₃ _ ₇ cycloalkyl-Ci_ ₄ alkoxy, C ₃ _ ₇ cycloalkenyl, heteroaryl, heteroaryl-Ci_ ₄ alkyl,

heteroaryl-C i_ ₄ alkyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl,

heteroaryl-C i_ ₄ alkyl-carbonyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl-C i_ ₄ alkyl, heteroaryl-C i_ ₄ alkyl-carbonyl-amino-C i_ ₄ alkyl, heterocyclyl, heterocyclyl-C i- ₄ alkyl, heterocyclyl-Ci- ₄ alkoxy, phenyl, or phenyl-Ci_ ₄ alkoxy,

wherein heteroaryl is a saturated monocyclic or bicyclic ring system having 1, 2, or 3 heteroatom ring members selected from N, O, and S,

wherein heterocyclyl is a saturated or partially unsaturated monocyclic or bicyclic ring system having 1, 2, or 3 heteroatom ring members selected from N, O, and S, and

wherein each instance of phenyl, heteroaryl or heterocyclyl is optionally substituted with 1, or 2 substituents each selected from R ₃ ; R ₂ is halogen, hydroxyl, cyano, oxo, hydroxyl-imino, Ci- ₄ alkyl, halo-Ci- ₄ alkyl, amino, Ci- ₄ alkyl-amino, (Ci_ ₄ alkyl) ₂ -amino, amino-Ci- ₄ alkyl, Ci- ₄ alkyl-amino-Ci- ₄ alkyl,

(Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkyl, amino-carbonyl, hydroxyl-Ci_ ₄ alkyl, Ci_ ₄ alkoxy,

Ci_ ₄ alkoxy-carbonyl, C ₂ _ ₄ alkenyl, C3_ ₇ cycloalkyl, or heterocyclyl-Ci_ ₄ alkyl,

wherein heterocyclyl is a saturated or partially unsaturated monocyclic or bicyclic ring system having 1, 2, or 3 heteroatom ring members selected from N, O, and S, and

wherein each instance of heterocyclyl is optionally substituted with 1, or 2 substituents each selected from R ₃ ;

R ₃ is halogen, hydroxyl, nitro, oxo, hydroxyl-imino, Ci- ₄ alkyl, halo-Ci- ₄ alkyl, amino,

Ci- ₄ alkyl-amino, (Ci_ ₄ alkyl) ₂ -amino, amino-Ci- ₄ alkyl, Ci- ₄ alkyl-amino-Ci- ₄ alkyl,

(Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkyl, amino-carbonyl, Ci_ ₄ alkyl-amino-carbonyl,

(Ci_ ₄ alkyl) ₂ -amino-carbonyl, Ci_ ₄ alkyl-amino-carbonyl-Ci_ ₄ alkyl, (Ci_ ₄ alkyl) ₂ -amino- carbonyl-Ci- ₄ alkyl, Ci- ₄ alkyl-carbonyl-amino, Ci- ₄ alkyl-carbonyl-amino-Ci- ₄ alkyl, hydroxyl-Ci_ ₄ alkyl, Ci- ₄ alkyl-carbonyl, Ci- ₄ alkoxy, halo-Ci- ₄ alkoxy, amino-Ci- ₄ alkoxy, hydroxyl-C i_ ₄ alkoxy, C i_ ₄ alkyl-C i- ₄ alkoxy, C i_ ₄ alkyl-amino-C i_ ₄ alkoxy,

(Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkoxy, Ci_ ₄ alkyl-carbonyl-amino-Ci_ ₄ alkoxy, Ci_ ₄ alkoxy- Ci- ₄ alkoxy, Ci- ₄ alkoxy-carbonyl, Ci- ₄ alkoxy-carbonyl-amino, Ci- ₄ alkoxy-carbonyl- amino-Ci_ ₄ alkoxy, C ₂ - ₄ alkenyl, C ₂ - ₄ alkenyl-amino-carbonyl, C ₃ _ ₇ cycloalkyl,

C ₃ _ ₇ cycloalkyl-Ci_ ₄ alkoxy, C ₃ _ ₇ cycloalkenyl, heteroaryl, heteroaryl-Ci_ ₄ alkyl,

heteroaryl-C i_ ₄ alkyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl,

heteroaryl-C i_ ₄ alkyl-carbonyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl-C i- ₄ alkyl, heteroaryl-C i_ ₄ alkyl-carbonyl-amino-C i- ₄ alkyl, heterocyclyl, heterocyclyl-C i- ₄ alkyl, phenyl, or phenyl-Ci- ₄ alkoxy;

R4 is independently selected from halogen, Ci_ ₄ alkyl, hydroxyl-C i_ ₄ alkyl, amino, Ci^alkyl- amino, (Ci_ ₄ alkyl) ₂ -amino or hydroxyl-C i_ ₄ alkyl-amino; and

R5 is hydrogen, Ci- ₄ alkyl, or hydroxyl-C i- ₄ alkyl;

wherein a form of the compound is selected from the group consisting of a prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof. An embodiment of the present description further relates to a method or use of a compound for treating or ameliorating HD in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I) selected from a compound of Formula (la) and Formula (lb :

(la) (lb)

or a form thereof, wherein

X is CH ₂ , CH(Ci_ ₄ alkyl), C(Ci_ ₄ alkyl) ₂ , CH=CH, O, NR ₅ , or a bond;

A is aryl, heteroaryl, heterocyclyl, or C9_iocycloalkyl,

wherein aryl is selected from phenyl and naphthyl, each optionally substituted with 1, 2, 3, or 4 substituents each selected from Ri,

wherein heteroaryl is a saturated monocyclic, bicyclic or tricyclic ring system having 1, 2, or 3 heteroatom ring members independently selected from N, O, or S, each optionally substituted with 1, 2, 3, 4, or 5 substituents each selected from Ri,

wherein heterocyclyl is a saturated or partially unsaturated monocyclic, bicyclic or tricyclic ring system having 1, 2, or 3 heteroatom ring members independently selected from N, O, or S, each optionally substituted with 1, 2, 3, 4, or 5 substituents each selected from R ₂ , and wherein C9_iocycloalkyl is a saturated or partially unsaturated bicyclic ring system optionally substituted with 1, 2, 3, 4, or 5 substituents each selected from R ₂ ;

B is heterocyclyl,

wherein heterocyclyl is a saturated or partially unsaturated monocyclic, bicyclic or polycyclic ring system having 1, 2, or 3 heteroatom ring members independently selected from N, O, or S, each optionally substituted with 1, 2, 3, 4, or 5 substituents each selected from R ₄ ;

Ri is halogen, hydroxyl, cyano, Ci_ ₄ alkyl, halo-Ci_ ₄ alkyl, amino, Ci_ ₄ alkyl- amino,

(Ci_ ₄ alkyl) ₂ -amino, amino-Ci_ ₄ alkyl, Ci- ₄ alkyl-amino-Ci_ ₄ alkyl,

(Ci- ₄ alkyl) ₂ -amino-Ci_ ₄ alkyl, amino-carbonyl, Ci_ ₄ alkyl-amino-carbonyl,

Ci_ ₄ alkyl-amino-carbonyl-Ci_ ₄ alkyl, Ci_ ₄ alkyl-carbonyl-amino, Ci_ ₄ alkyl-carbonyl-amino- Ci_ ₄ alkyl, hydroxyl-Ci_ ₄ alkyl, Ci_ ₄ alkyl-carbonyl, Ci_ ₄ alkoxy, halo-Ci_ ₄ alkoxy, amino- Ci_ ₄ alkoxy, hydroxyl-Ci_ ₄ alkoxy, Ci_ ₄ alkyl-Ci_ ₄ alkoxy, Ci_ ₄ alkyl-amino-Ci_ ₄ alkoxy, (Ci- ₄ alkyl) ₂ -amino-Ci_ ₄ alkoxy, Ci- ₄ alkyl-carbonyl-amino-Ci_ ₄ alkoxy, Ci_ ₄ alkoxy- Ci- ₄ alkoxy, Ci- ₄ alkoxy-carbonyl, Ci- ₄ alkoxy-carbonyl-amino, Ci- ₄ alkoxy-carbonyl- amino-Ci- ₄ alkoxy, C ₂ - ₄ alkenyl, C ₂ - ₄ alkenyl-amino-carbonyl, C ₃ _ ₇ cycloalkyl,

C ₃ _ ₇ cycloalkyl-Ci_ ₄ alkoxy, C ₃ _ ₇ cycloalkenyl, heteroaryl, heteroaryl-Ci_ ₄ alkyl,

heteroaryl-C i_ ₄ alkyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl,

heteroaryl-C i_ ₄ alkyl-carbonyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl-C i- ₄ alkyl, heteroaryl-C i_ ₄ alkyl-carbonyl-amino-C i- ₄ alkyl, heterocyclyl, heterocyclyl-C i- ₄ alkyl, heterocyclyl-Ci- ₄ alkoxy, phenyl, or phenyl-Ci_ ₄ alkoxy,

wherein heteroaryl is a saturated monocyclic or bicyclic ring system having 1, 2, or 3 heteroatom ring members selected from N, O, and S,

wherein heterocyclyl is a saturated or partially unsaturated monocyclic or bicyclic ring system having 1, 2, or 3 heteroatom ring members selected from N, O, and S, and

wherein each instance of phenyl, heteroaryl or heterocyclyl is optionally substituted with 1, or 2 substituents each selected from R ₃ ;

R ₂ is halogen, hydroxyl, cyano, oxo, hydroxyl-imino, Ci- ₄ alkyl, halo-Ci- ₄ alkyl, amino,

Ci_ ₄ alkyl-amino, (Ci_ ₄ alkyl) ₂ -amino, amino-Ci_ ₄ alkyl, amino-carbonyl,

hydroxyl-Ci_ ₄ alkyl, Ci_ ₄ alkoxy, Ci_ ₄ alkoxy-carbonyl, C ₂ _ ₄ alkenyl, C ₃ _ ₇ cycloalkyl, or heterocyclyl-C i_ ₄ alkyl;

R ₃ is halogen, hydroxyl, nitro, oxo, hydroxyl-imino, Ci- ₄ alkyl, amino, Ci- ₄ alkyl-amino,

(Ci_ ₄ alkyl) ₂ -amino, amino-Ci_ ₄ alkyl, Ci_ ₄ alkyl-amino-Ci_ ₄ alkyl,

(Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkyl, amino-carbonyl, Ci_ ₄ alkyl-amino-carbonyl,

Ci- ₄ alkyl-amino-carbonyl-Ci- ₄ alkyl, Ci- ₄ alkyl-carbonyl-amino, Ci- ₄ alkyl-carbonyl-amino- Ci- ₄ alkyl, hydroxyl-Ci- ₄ alkyl, Ci- ₄ alkyl-carbonyl, Ci- ₄ alkoxy, halo-Ci- ₄ alkoxy, amino- Ci_ ₄ alkoxy, hydroxyl-Ci_ ₄ alkoxy, Ci_ ₄ alkyl-Ci_ ₄ alkoxy, Ci_ ₄ alkyl-amino-Ci_ ₄ alkoxy, (Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkoxy, Ci_ ₄ alkyl-carbonyl-amino-Ci_ ₄ alkoxy, Ci_ ₄ alkoxy- Ci- ₄ alkoxy, Ci- ₄ alkoxy-carbonyl, Ci- ₄ alkoxy-carbonyl-amino, Ci- ₄ alkoxy-carbonyl- amino-Ci_ ₄ alkoxy, C ₂ - ₄ alkenyl, C ₂ - ₄ alkenyl-amino-carbonyl, C ₃ _ ₇ cycloalkyl,

C ₃ _ ₇ cycloalkyl-Ci- ₄ alkoxy, C ₃ _ ₇ cycloalkenyl, heteroaryl, heteroaryl-C i_ ₄ alkyl,

heteroaryl-C i_ ₄ alkyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl,

heteroaryl-C i_ ₄ alkyl-carbonyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl-C i- ₄ alkyl, heteroaryl-C i_ ₄ alkyl-carbonyl-amino-C i- ₄ alkyl, heterocyclyl, heterocyclyl-C i- ₄ alkyl, phenyl, or phenyl-Ci_ ₄ alkoxy; R ₄ is independently selected from halogen, Ci_ ₄ alkyl, hydroxyl-Ci_ ₄ alkyl, amino, Ci^alkyl- amino, (Ci_ ₄ alkyl)2-amino or hydroxyl-Ci_ ₄ alkyl-amino; and

R5 is hydrogen, Ci_ ₄ alkyl, or hydroxyl-Ci_ ₄ alkyl;

wherein a form of the compound is selected from the group consisting of a prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

Another embodiment of the present description further relates to methods for treating or ameliorating HD in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I) selected from a compound of Formula (la) and Formula (lb):

(la)

or a form thereof, wherein

X is O, NH, N(CH ₃ ) or a bond;

A is aryl, heteroaryl or heterocyclyl,

wherein aryl is selected from the group consisting

al a2 a3 wherein heteroar l is selected from the group consisting of

a4 a5 a6 a7



10

b25 b26, and b27

Ri _a , Ri _b and Ri _c are each, where allowed by available valences, one or more substituents each selected from halogen, hydroxyl, cyano, Ci- ₄ alkyl, halo-Ci- ₄ alkyl, amino,

Ci_ ₄ alkyl-amino, (Ci_ ₄ alkyl) ₂ -amino, amino-Ci_ ₄ alkyl, Ci_ ₄ alkyl-amino-Ci_ ₄ alkyl, (Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkyl, amino-carbonyl, Ci_ ₄ alkyl-amino-carbonyl,

(Ci_ ₄ alkyl) ₂ -amino-carbonyl, Ci_ ₄ alkyl-amino-carbonyl-Ci_ ₄ alkyl, (Ci_ ₄ alkyl) ₂ -amino- carbonyl-Ci- ₄ alkyl, Ci- ₄ alkyl-carbonyl-amino, Ci- ₄ alkyl-carbonyl-amino-Ci- ₄ alkyl, hydroxyl-Ci_ ₄ alkyl, Ci- ₄ alkyl-carbonyl, Ci- ₄ alkoxy, halo-Ci- ₄ alkoxy, amino-Ci- ₄ alkoxy, hydroxyl-C i_ ₄ alkoxy, C i_ ₄ alkyl-C i_ ₄ alkoxy, C i_ ₄ alkyl-amino-C i_ ₄ alkoxy,

(Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkoxy, Ci_ ₄ alkyl-carbonyl-amino-Ci_ ₄ alkoxy, Ci_ ₄ alkoxy- Ci- ₄ alkoxy, Ci- ₄ alkoxy-carbonyl, Ci- ₄ alkoxy-carbonyl-amino, Ci- ₄ alkoxy-carbonyl- amino-Ci_ ₄ alkoxy, C ₂ - ₄ alkenyl, C ₂ - ₄ alkenyl-amino-carbonyl, C ₃ _ ₇ cycloalkyl,

C ₃ _ ₇ cycloalkyl-Ci_ ₄ alkoxy, C ₃ _ ₇ cycloalkenyl, heteroaryl, heteroaryl-Ci_ ₄ alkyl, heteroaryl-C i_ ₄ alkyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl,

heteroaryl-C i_ ₄ alkyl-carbonyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl-C i- ₄ alkyl, heteroaryl-C i_ ₄ alkyl-carbonyl-amino-C i- ₄ alkyl, heterocyclyl, heterocyclyl-C i- ₄ alkyl, heterocyclyl-Ci- ₄ alkoxy, phenyl, or phenyl-Ci_ ₄ alkoxy,

wherein heteroaryl is a saturated monocyclic or bicyclic ring system having 1, 2, or 3 heteroatom ring members selected from N, O, and S,

wherein heterocyclyl is a saturated or partially unsaturated monocyclic or bicyclic ring system having 1, 2, or 3 heteroatom ring members selected from N, O, and S, and

wherein each instance of phenyl, heteroaryl or heterocyclyl is optionally substituted with 1, or 2 substituents each selected from R ₃ ;

R _2a , R _2b and R _2C are each, where allowed by available valences, one or more substituents each selected from halogen, hydroxyl, cyano, oxo, hydroxyl-imino, Ci_ ₄ alkyl, halo-Ci_ ₄ alkyl, amino, Ci_ ₄ alkyl-amino, (Ci_ ₄ alkyl) ₂ -amino, amino-Ci_ ₄ alkyl, Ci_ ₄ alkyl-amino-Ci_ ₄ alkyl, (Ci- ₄ alkyl) ₂ -amino-Ci_ ₄ alkyl, amino-carbonyl, hydroxyl-Ci- ₄ alkyl, Ci- ₄ alkoxy,

Ci- ₄ alkoxy-carbonyl, C ₂ - ₄ alkenyl, C3_ ₇ cycloalkyl, or heterocyclyl-Ci- ₄ alkyl,

wherein heterocyclyl is a saturated or partially unsaturated monocyclic or bicyclic ring system having 1, 2, or 3 heteroatom ring members selected from N, O, and S, and

wherein each instance of heterocyclyl is optionally substituted with 1, or 2 substituents each selected from R ₃ ;

R ₃ is halogen, hydroxyl, nitro, oxo, hydroxyl-imino, Ci_ ₄ alkyl, amino, Ci_ ₄ alkyl-amino,

(Ci_ ₄ alkyl) ₂ -amino, amino-Ci_ ₄ alkyl, Ci_ ₄ alkyl-amino-Ci_ ₄ alkyl,

(Ci- ₄ alkyl) ₂ -amino-Ci_ ₄ alkyl, amino-carbonyl, Ci- ₄ alkyl-amino-carbonyl,

(Ci- ₄ alkyl) ₂ -amino-carbonyl, Ci- ₄ alkyl-amino-carbonyl-Ci- ₄ alkyl, (Ci_ ₄ alkyl) ₂ -amino- carbonyl-Ci_ ₄ alkyl, Ci_ ₄ alkyl-carbonyl-amino, Ci_ ₄ alkyl-carbonyl-amino-Ci_ ₄ alkyl, hydroxyl-Ci_ ₄ alkyl, Ci_ ₄ alkyl-carbonyl, Ci_ ₄ alkoxy, halo-Ci_ ₄ alkoxy, amino-Ci_ ₄ alkoxy, hydroxyl-C i_ ₄ alkoxy, C i_ ₄ alkyl-C i_ ₄ alkoxy, C i_ ₄ alkyl-amino-C i_ ₄ alkoxy,

(Ci- ₄ alkyl) ₂ -amino-Ci_ ₄ alkoxy, Ci- ₄ alkyl-carbonyl-amino-Ci- ₄ alkoxy, Ci- ₄ alkoxy- Ci_ ₄ alkoxy, Ci_ ₄ alkoxy-carbonyl, Ci_ ₄ alkoxy-carbonyl-amino, Ci_ ₄ alkoxy-carbonyl- amino-Ci_ ₄ alkoxy, C ₂ - ₄ alkenyl, C ₂ - ₄ alkenyl-amino-carbonyl, C ₃ _ ₇ cycloalkyl,

C ₃ - ₇ cycloalkyl-Ci_ ₄ alkoxy, C ₃ _ ₇ cycloalkenyl, heteroaryl, heteroaryl-Ci- ₄ alkyl,

heteroaryl-C i_ ₄ alkyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl,

heteroaryl-C i_ ₄ alkyl-carbonyl-amino, heteroaryl-C i_ ₄ alkyl-amino-carbonyl-C i_ ₄ alkyl, heteroaryl-C i_ ₄ alkyl-carbonyl-amino-C i_ ₄ alkyl, heterocyclyl, heterocyclyl-C i_ ₄ alkyl, phenyl, or phenyl-Ci- ₄ alkoxy; and

R4a, R4b, R4c, R4d, R4e, ¾4f and R4 _g are independently selected from halogen, Ci-4alkyl,

hydroxyl-C i_ ₄ alkyl, amino, Ci_ ₄ alkyl-amino, (Ci_ ₄ alkyl) ₂ -amino or

hydroxyl-C i _ ₄ alkyl- amino ;

wherein a form of the compound is selected from the group consisting of a prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof. Another aspect of the present description relates to a compound of Formula (I) selected from a com ound of Formula (lal 1), Formula (Ial5), Formula (Ial8) or Formula (Ibl):

(Ial8), (Ibl) or a form thereof, wherein (when present),

X is selected from O, NR ₅ , or a bond;

A is selected from phenyl, thiophenyl, indazolyl, pyridinyl, pyrimidinyl or phenoxy, wherein phenyl and phenoxy are each optionally substituted with 1, 2 or 3 substituents each selected from Ri _a ,

wherein thiophenyl, indazolyl, pyridinyl, pyrimidinyl are each optionally substituted with 1 or 2 substituents each selected from Ri _a ,

B is selected from lH-pyrazolyl, piperidinyl, 1,2,3,6-tetrahydropyridinyl, ( IR,5S)-S- azabicyclo[3.2.1]octyl, 8-azabicyclo[3.2.1]oct-2-enyl, 2,6-diazaspiro[3.4]octyl or 2,7- diazaspiro[3.5]nonyl, each optionally substituted with 1 or 2 substituents each selected from R _4a ;

Ri _a is selected from halogen, hydroxyl, Ci_ ₄ alkyl, halo-Ci_ ₄ alkyl, amino, Ci_ ₄ alkoxy, or

heteroaryl,

wherein heteroaryl is a saturated monocyclic or bicyclic ring system having 1, 2, or 3 heteroatom ring members selected from N, O, and S optionally substituted with 1 or 2 substituents each selected from R _3a ;

R _3a is selected from nitro or Ci_ ₄ alkyl; and,

R _4a is Ci- ₄ alkyl;

R5 _a is hydrogen, Ci_ ₄ alkyl, or hydroxyl-Ci_ ₄ alkyl; wherein a form of the compound is selected from the group consisting of a prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

Another aspect of the present description relates to a compound of Formula (I) selected from a compound of Formula (lal 1), Formula (Ial5), Formula (Ial8) or Formula (Ibl):

or a form thereof, wherein (when present),

Ri _a is selected from fluoro, chloro, hydroxyl, methyl, difluoromethyl, amino, methoxy or 1H- pyrazolyl or lH-imidazol-l-yl,

wherein lH-pyrazolyl is optionally substituted with 1 or 2 substituents each selected from R _3a ; R _3a is selected from nitro or methyl or amino; and,

R _4a is methyl or ethyl;

Rs _a is hydrogen or methyl;

wherein a form of the compound is selected from the group consisting of a prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (lal) or a form thereof, wherein substituents Ri _a , Ri _b , and X, when present, are indicated in the table below with multiple substituents separated by a comma; and, "— " indicates that one or more Ri _a , R^, and X substituents are not present:

(la

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ia2) or a form thereof, wherein substituents Ri _a , Ri _b , and R _4a , when present, are indicated in the table below with multiple substituents separated by a comma; and, "— " indicates that one or more Ri _a , Ri , and R _4a substituents are not present:

(Ia2)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ia3) or a form thereof, wherein substituents Ri _a , and X, when present, are indicated in the table below with multiple substituents separated by a comma; and, "— " indicates that one or more Ri _a , and X substituents are not present:

(Ia3)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ia4) or a form thereof, wherein substituents X, Ri _a , Ri _b and R _4a , when present, are indicated in the table below; and, "— " indicates that one or more X, Ri _a , Ri _b and R _4a substituents are not present:

(Ia4)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ia5) or a form thereof, wherein substituents Ri _a and Ri _b , when present, are indicated in the table below with multiple substituents separated by a comma; and, "— " indicates that one or more Ri _a and substituents are not present:

(Ia5)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ia6) or a form thereof, wherein substituents Ri _a , when present, are indicated in the table below; and, "— indicates that one or more Ri _a substituents are not present:

(Ia6)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ia7) or a form thereof, wherein substituents Ri _a , when present, are indicated in the table below; and, "— indicates that one or more Ri _a substituents are not present:

(Ia7) Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ia8) or a form thereof, wherein substituents Ri _a and B, when present, are indicated in the table below; and, "— " indicates that one or more Ri _a and B substituents are not present:

(Ia8)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ia9) or a form thereof, wherein substituents Ri _a and B, when present, are indicated in the table below; and, "— " indicates that one or more Ri _a and B substituents are not present:

(Ia9)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (la 10) or a form thereof, wherein substituents Ri _a and B, when present, are indicated in the table below; and, "— " indicates that one or more Ri _a and B substituents are not present:

(IalO)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (lal 1) or a form thereof, wherein substituents A, X and R _4a , when present, are indicated in the table below; and, "— " indicates that one or more A, X and R _4a substituents are not present:

(M l)

Cpd A X _4a

20 quinoxalin-2-yl N(CH ₃ ) —

21 quinolin-3-yl N(CH ₃ ) —

22 phthalazin-6-yl N(CH ₃ ) —

23 benzo[c][l,2,5]oxadiazol-5-yl NH -

24 benzo [d] thiazol-5-yl NH -

25 2-CH ₃ -benzo [d] oxazol-6-yl NH -

30 2-(4-CN-phenol) N(CH ₃ ) —

32 2-(4-CF ₃ -phenol) N(CH ₃ ) —

33 6-(2-F-phenol) N(CH ₃ ) —

34 2-[3,5-(OCH ₃ ) ₂ -phenol] N(CH ₃ ) —

35 2-[4,5-(OCH ₃ ) ₂ -phenol] N(CH ₃ ) —

37 2-(4,5-F ₂ -phenol) N(CH ₃ ) —

41 benzo [b] thiophen-2-yl NH CH ₃

53 2-[4-(lH-pyrazol-l-yl)-phenol] N(CH ₃ ) —

115 2-[3-OH-5-(lH-pyrazol-4-yl)-phenol] N(CH ₃ ) —

116 2-[3-OCH ₃ -5-(lH-pyrazol-4-yl)-phenol] N(CH ₃ ) —

117 2-[5-(lH-pyrazol-4-yl)-3-OCF ₃ -phenol] NH -

118 2-[5-(l-CH ₃ -lH-pyrazol-4-yl)-3-OCF ₃ -phenol] N(CH ₃ ) —

119 2-[5-(lH-pyrazol-4-yl)-3-OCF ₃ -phenol] N(CH ₃ ) —

120 2-[5-(l-CH ₃ -pyridin-2(lH)-one)-3-OCF ₃ -phenol] N(CH ₃ ) —

121 2- [3-OCH ₃ -5-( 1 -CH ₃ - lH-pyrazol-4-yl)-phenol] N(CH ₃ ) —

2-[3-OCH ₃ -5-(5,6,7 8-tetrahydroimidazo-[l,2-

122 a]pyridin-3-yl)-phenol] N(CH ₃ )

123 2-[3-OCH ₃ -5-(pyridin-3-yl)-phenol] N(CH ₃ ) —

2- [3-OCH ₃ -5-( 1 -cyclopentyl- lH-pyrazol-4-yl)-

124 phenol] N(CH ₃ )

125 2-[5-(3-OCH ₃ -phenyl)-3-OCH ₃ -phenol] N(CH ₃ ) —

126 2-[3-benzyloxy-5-(5-CH ₃ -oxazol-2-yl)-phenol] N(CH ₃ ) —

127 2-[3-OCH ₂ CH ₃ -5-(5-CH ₃ -oxazol-2-yl)-phenol] N(CH ₃ ) —

2-[3-(OCH ₂ -cyclopropyl)-5-(5-CH ₃ -oxazol-2-yl)-

128 phenol] N(CH ₃ )

129 5-(2-CH ₃ -lH-benzo[d]imidazol-6-ol) N(CH ₃ ) —

134 2-[4-(lH-pyrazol-4-yl)-phenol] N(CH ₃ ) —

2-[4-(4,5,6,7-tetrahydropyrazolo[l,5-a]pyridin-3-

135 yl)-phenol] N(CH ₃ ) Cpd A X _4a

2-[4-(4,5,6,7-tetrahydropyrazolo[l,5-a]pyrazin-3-

136 yl)-phenol] N(CH ₃ )

137 2-[4-(lH-indol-2-yl)-phenol] N(CH ₃ ) —

138 2-[4-(cyclopent- 1 -en- 1 -yl)-phenol] N(CH ₃ ) —

139 2-[4-(lH-pyrazol-3-yl)-phenol] N(CH ₃ ) —

140 2- [4-(2-OH-pyridin-4-yl)-phenol] N(CH ₃ ) —

141 2[4-( 1 -CH ₃ -pyridin-2( 1 H)-one)-phenol] 0 —

142 2- [4-(2-OH-pyridin-4-yl)-phenol] 0 —

144 2- [4-Cl-5-( lH-pyrazol-4-yl)-phenol] N(CH ₃ ) —

145 2-[4-F-5-(lH-pyrazol-4-yl)-phenol] N(CH ₃ ) —

146 2- [5-F-4-( 1 H-imidazol-4-yl)-phenol] N(CH ₃ ) —

147 2- [5-F-4-( 1 H-pyrazol-4-yl)-phenol] N(CH ₃ ) —

148 2-[5-F-(lH-pyrazol-5-yl)-phenol] N(CH ₃ ) —

149 6-OH-l-oxo-2,3-dihydro-lH-inden-5-yl N(CH ₃ ) —

150 6-( 1 ,4-dihydroindeno [ 1 ,2-c] - 1 H-pyrazol-7-ol) N(CH ₃ ) —

151 6-OH- 1 -OH-imino-2,3 -dihydro- 1 H-inden-5 -yl N(CH ₃ ) —

152 6-OH-l-OH-2,3-dihydro-lH-inden-5-yl N(CH ₃ ) —

153 6-(2-NH ₂ -8H-indeno[l,2-d]thiazol-5-ol) N(CH ₃ ) —

154 9-(5 ,6-dihydroimidazo [5 , 1 -a] isoquinolin-8-ol) N(CH ₃ ) —

2- { 4- [C(0)NHCH ₂ -( 1 -CH ₃ - lH-pyrazol-4-yl)] -

155 phenol} N(CH ₃ )

156 2- [4-(4-CH ₂ OH- 1 H-pyrazol- 1 -yl)-phenol] N(CH ₃ ) —

158 3-(OCH ₂ -phenyl)-isoquinolin-6-yl N(CH ₃ ) —

160 2-[3-F-5-(2-OCH ₃ -pyridin-4-yl)-phenol] N(CH ₃ ) —

161 4-[l-(4-pyridin-2(lH)-one)-3-F-5-OH-phenyl] N(CH ₃ ) —

4- { 1 - [4-( 1 -CH ₃ -pyridin-2( lH)-one)] -3-F-5-OH-

162 phenyl} N(CH ₃ )

4- { 1 - [5-( 1 -CH ₃ -pyridin-2( lH)-one)] -3-F-5-OH-

163 phenyl} N(CH ₃ )

164 2- [3 - F-5-( 1 H-pyrazol-4-yl)-phenol] 0 —

165 2-(5-Cl-3-F-phenol) N(CH ₃ ) —

166 2- [3 - F-5-( 1 H-pyrazol-4-yl)-phenol] N(CH ₃ ) —

167 2-[3-F-5-(l-CH ₃ -lH-pyrazol-4-yl)-phenol] N(CH ₃ ) —

219 8-(quinolin-7-ol) N(CH ₃ ) —

230 6-(7-OH-quinolin-2(lH)-one) N(CH ₃ ) — Cpd A X _4a

231 6-(7-OH- 1 -CH ₃ -quinolin-2( lH)-one) N(CH ₃ ) —

245 7-(6-OH- 1 -CH ₃ -quinolin-4( lH)-one) N(CH ₃ ) —

257 6-(7-OH-quinazolin-4(lH)-one) N(CH ₃ ) —

259 6-(7-OH-l-CH ₃ -3,4-dihydroquinolin-2(lH)-one) N(CH ₃ ) -

7-OH-l,3-(CH ₃ ) ₂ -quinazolin-6-yl-2,4(lH,3H)-

277 dione N(CH ₃ )

278 6-OH-benzo[d]oxazol-5-yl-2(3H)-one N(CH ₃ ) —

279 2-CH ₃ -6-OH-2H-indazol-5-yl N(CH ₃ ) —

280 l-CH ₃ -6-OH- lH-indazol-5-yl N(CH ₃ ) —

281 7-(6-OH-2-CH ₃ -isoquinolin- 1 (2H)-one) N(CH ₃ ) —

282 7-(6-OH-2-CH ₂ CH ₃ -isoquinolin- 1 (2H)-one) 0 -

Another embodiment of the present description includes a compound of Formula (la) or a form thereof selected from a compound of Formula (lal 1) or a form thereof, wherein

substituents A, X and R _4a , when present, are indicated in the table below; and, "— " indicates that one or more A, X and R _4a substituents are not present:

(M l)

Cpd A X

442 2-CH ₃ -2H-indazol-5-yl N(CH ₃ )

443 2-CH ₃ -2H-indazol-5-yl 0

444 4-Cl-2-OCH ₃ -phenyl 0

445 2-CH ₃ -pyrazolo[l,5-a]pyridin-3-yl N(CH ₃ )

446 imidazo[ 1 ,2-a]pyridin-6-yl 0

447 2-OCH ₃ -4-( IH-pyrazol- 1 -yl)phenyl 0

448 5-(lH-pyrazol-4-yl)thiophen-2-yl 0

449 5-(l-CH ₃ -lH-pyrazol-4-yl)thiophen-2-yl 0

450 4-(lH-pyrazol-4-yl)thiophen-2-yl 0

451 2-OH-4-[3,5-(CH ₃ ) ₂ -lH-pyrazol-4-yl]phenyl 0

452 2-F-4-(lH-pyrazol-4-yl)phenyl N(CH ₃ )

453 2-OCH ₃ -4-OH-phenyl 0

454 2-OCH ₃ -4-(4-N0 ₂ - IH-pyrazol- l-yl)phenyl 0

455 2,4-(OH) ₂ -phenyl 0

456 2-Cl-4-(lH-pyrazol-4-yl)phenyl N(CH ₃ )

457 5-amino-2-(lH-pyrazol-4-yl)pyrimidin-4-yl 0

458 2,6-F ₂ -4-(lH-pyrazol-4-yl)phenyl 0

464 2-(CHF ₂ )-4-(lH-pyrazol-4-yl)phenyl 0

465 2-(CHF ₂ )-4-(lH-pyrazol-4-yl)phenyl N(CH ₃ )

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (lal 1) or a form thereof, wherein substituents A, X and R _4a , when present, are indicated in the table below; and, "— " indicates that one or more A, X and R _4a substituents are not present:

(M l)

Cpd A X

452 2-F-4-(lH-pyrazol-4-yl)phenyl N(CH ₃ )

453 2-OCH ₃ -4-OH-phenyl 0

454 2-OCH ₃ -4-(4-N0 ₂ - lH-pyrazol- l-yl)phenyl 0

455 2,4-(OH) ₂ -phenyl 0

456 2-Cl-4-(lH-pyrazol-4-yl)phenyl N(CH ₃ )

457 5-amino-2-(lH-pyrazol-4-yl)pyrimidin-4-yl 0

458 2,6-F ₂ -4-(lH-pyrazol-4-yl)phenyl 0

464 2-(CHF ₂ )-4-(lH-pyrazol-4-yl)phenyl 0

465 2-(CHF ₂ )-4-(lH-pyrazol-4-yl)phenyl N(CH ₃ )

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (la 12) or a form thereof, wherein substituents X, Ri _a and B, when present, are indicated in the table below; and, "— " indicates that one or more X, Ri _a and B substituents are not present:

(Ial2)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ial3) or a form thereof, wherein substituents X, Ri _a and R _4a , when present, are indicated in the table below; and, "— " indicates that one or more X, Ri _a and R _4a substituents are not present:

(Ial3)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (la 14) or a form thereof, wherein substituents X and B, when present, are indicated in the table below; and, "— " indicates that one or more X and B substituents are not present:

(Ial4)

Cpd X B

102 0 (6S)-6-[(S)-CH(OH)CH ₃ ]-2,2-(CH ₃ ) ₂ -piperidin-4-yl

133 0 2,2-(CH ₃ ) ₂ -piperidin-4-yl

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ial5) or a form thereof, wherein substituents X, Ri _a and R _4a , when present, are indicated in the table below; and, "— " indicates that one or more X, Ri _a and R _4a substituents are not present:

(Ial5)

Another embodiment of the present description includes a compound of Formula (la) or a form thereof selected from a compound of Formula (Ial5) or a form thereof, wherein

substituents X, Ri _a and R4 _a , when present, are indicated in the table below; and, "— " indicates that one or more X, Ri _a and R _4a substituents are not present:

(Ial5)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ial5) or a form thereof, wherein substituents X, Ri _a and R _4a , when present, are indicated in the table below; and, "— " indicates that one or more X, Ri _a and R _4a substituents are not present:

(Ial5)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (la 16) or a form thereof, wherein substituents Ri _a and R4 _a , when present, are indicated in the table below; and, "— " indicates that one or more Ri _a and R _4a substituents are not present:

(Ial6)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ial7) o form thereof, wherein substituent Ri _a , when present, is indicated in the table below; and, "— indicates that one or more Ri _a substituents are not present:

(Ial7) Another embodiment of the present description includes a compound of Formula (la) or a form thereof selected from a compound of Formula (Ial8) or a form thereof, wherein

substituents X and B, when present, are indicated in the table below; and, "— " indicates that one or more X and B substituents are not present:

(Ial8)

Another embodiment of the method of the present description includes the use of a compound of Formula (la) or a form thereof selected from a compound of Formula (Ial8) or a form thereof, wherein substituents X, Ri _a and B, when present, are indicated in the table below; and, "— " indicates that one or more X, Ri _a and B substituents are not present:

(Ial8)

Another embodiment of the method of the present description includes the use of a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ibl) or a form thereof, wherein substituent A is indicated in the table below:

(Ibl)

Another embodiment of the present description includes a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ibl) or a form thereof, wherein substituent A is indicated in the table below Another embodiment of the method of the present description includes the use of a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ibl) or a form thereof, wherein substituent A is indicated in the table below:

(Ibl)

Another embodiment of the method of the present description includes the use of a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ib2) or a form thereof, wherein substituent A is indicated in the table below:

(Ib2)

Another embodiment of the method of the present description includes the use of a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ib3) or a form thereof, wherein substituents Ri _a , and B, when present, are indicated in the table below; and, "— " indicates that one or more Ri _a , and B substituents are not present:

(Ib3)

Another embodiment of the ccpresent description includes the use of a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ib4) or a form thereof, wherein substituents Ri _a , R^, Ri _c , Ri _d (each representative of the scope of Ri) and X, when present, are indicated in the table below; and, "— " indicates that one or more Ri _a , R^, Ri _c , Ri _d and X substituents are not present:

(Ib4)

Another embodiment of the method of the present description includes the use of a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ib5) or a form thereof, wherein substituents Ri _a , R^, Ri _c , Ri _d (each representative of the scope of Ri) and R _4a , when present, are indicated in the table below; and, "— " indicates that one or more Ri _a , R^, Ri _c , Ri _d and R4 _a substituents are not present:

(Ib5)

Another embodiment of the method of the present description includes the use of a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ib6) or a form thereof, wherein substituents Ri _a , R^, Ri _c and R^ (each representative of the scope of Ri), when present, are indicated in the table below; and, "— " indicates that one or more Ri _a , Ri _b , Ri _c and Ri _d substituents are not present:

(Ib6)

Another embodiment of the method of the present description includes the use of a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ib7) or a form thereof, wherein substituent Ri _b , when present, is indicated in the table below:

Another embodiment of the method of the present description includes the use of a compound of Formula (lb) or a form thereof selected from a compound of Formula (Ib8) or a form thereof, wherein substituent Rib, when present, is indicated in the table below:

An embodiment of the use of a compound of Formula (I) or a form thereof includes a method of use of a compound of Formula (I) or a form thereof for treating or ameliorating HD a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof to the subject, selected from the group consisting of:

5 6



80

wherein a form of the compound is selected from the group consisting of a prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

In another aspect, the compound of Formula (I) or a form thereof includes a compound selected from the group consisting of:

415

465

wherein a form of the compound is selected from the group consisting of a prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

Another embodiment of the use of a compound of Formula (I) or a form thereof includes a method of use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof (wherein compound number (#*) indicates that the salt form was isolated) to the subject, selected from the group consisting of:

Cpd Name

1 6-(naphthalen-2-yl)-N-(2,2,6,6-tetramethylpiperidin-4-yl)pyr idazin-3-amine

6-(benzo[b]thiophen-2-yl)-N-methyl-N-(2,2,6,6-tetramethylpip eridin-4-yl)pyridazin-3-

2 amine

3 2-(6-(2,2,6,6-tetramethylpiperidin-4-yl-amino)-pyridazin-3-y l)phenol

2-(6-(methyl-(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyrida zin-3-yl)benzo[b]-

4 thiophene-5-carbonitrile

5 6-(quinolin-3-yl)-N-(2,2,6,6-tetramethylpiperidin-4-yl)pyrid azin-3-amine

6 3-(benzo[b]-thiophen-2-yl)-6-(2,2,6,6-tetramethylpiperidin-4 -yl-oxy)pyridazine

7 2-(6-(methyl-(2,2,6,6-tetramethylpiperidin-4-yl)amino)-pyrid azin-3-yl)phenol

8 6-(6-(methyl-(2,2,6,6-tetramethylpiperidin-4-yl)amino)-pyrid azin-3-yl)naphthalen-2-ol

9 6-(benzo[b]-thiophen-2-yl)-N-(2,2,6,6-tetramethylpiperidin-4 -yl)pyridazin-3-amine

10 7-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)pyridazin-3-yl) isoquinoline

11 6-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)pyridazin-3-yl) isoquinoline

12 N-methyl-6-(quinolin-7-yl)-N-(2,2,6,6-tetramethylpiperidin-4 -yl)pyridazin-3-amine Cpd Name

13 N-methyl-6-(quinolin-6-yl)-N-(2,2,6,6-tetramethylpiperidin-4 -yl)pyridazin-3-amine

14 6-(isoquinolin-7-yl)-N-methyl-N-(2,2,6,6-tetramethylpiperidi n-4-yl)pyridazin-3-amine

15 6-(isoquinolin-6-yl)-N-methyl-N-(2,2,6,6-tetramethylpiperidi n-4-yl)pyridazin-3-amine

6-(imidazo[l,2-a]pyridin-6-yl-pyridazin-3-yl)-methyl-(2,2 ,6,6-tetramethylpiperidin-4-

16 yl)- amine

N-methyl-6-(6-phenylpyridin-3-yl)-N-(2,2,6,6-tetramethylpipe ridin-4-yl)pyridazin-3-

17 amine

6-(6-(lH-pyrrol-l-yl)pyridin-3-yl)-N-methyl-N-(2,2,6,6-tetra methylpiperidin-4-

18 yl)pyridazin-3-amine

6-(6-(lH-pyrazol-l-yl)pyridin-3-yl)-N-methyl-N-(2,2,6,6-tetr amethylpiperidin-4-

19 yl)pyridazin-3-amine

20 methyl-(6-quinoxalin-2-yl-pyridazin-3-yl)-(2,2,6,6-tetrameth ylpiperidin-4-yl)-amine

21 methyl-(6-quinolin-3-yl-pyridazin-3-yl)-(2,2,6,6-tetramethyl piperidin-4-yl)-amine

22 N-methyl-6-(phthalazin-6-yl)-N-(2,2,6,6-tetramethylpiperidin -4-yl)pyridazin-3-amine

6-(benzo[c][l,2,5]oxa-diazol-5-yl)-N-(2,2,6,6-tetramethyl piperidin-4-yl)pyridazin-3-

23 amine

24 6-(benzo[d]thiazol-5-yl)-N-(2,2,6,6-tetramethylpiperidin-4-y l)pyridazin-3-amine

6-(2-methylbenzo-[d]oxazol-6-yl)-N-(2,2,6,6-tetramethylpiper idin-4-yl)pyridazin-3-

25 amine

26 3-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)naphthalen-2-ol

27 5-chloro-2-(6-(methyl(l, 2,2,6, 6-pentamethylpiperidin-4-yl)amino)pyridazin-3-yl)phenol

28 3-(6-(2,2,6,6-tetramethylpiperidin-4-yl-amino)pyridazin-3-yl )naphthalen-2-ol

29 5-chloro-2-(6-(l, 2,2,6, 6-pentamethylpiperidin-4-ylamino)pyridazin-3-yl)phenol

4-hydroxy-3-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

30 yl)benzonitrile

31 3-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)pyridazin-3-yl) naphthalen-2-ol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-4- 32 ¹ (trifluoromethyl)phenol

33 2-fluoro-6-(6-(methyl-(2,2,6,6-tetramethylpiperidin-4-yl)-am ino)-pyridazin-3-yl)phenol

3,5-dimethoxy-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4 -yl)amino)pyridazin-3-

34 yl)phenol

4,5-dimethoxy-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl )amino)pyridazin-3-

35 yl)phenol

36 5-methoxy-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-yl)phenol

4,5-difluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4- yl)amino)pyridazin-3-

37 yl)phenol

38 5-fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)phenol Cpd Name

3-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

39 yl)benzonitrile

1- allyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)p yridazin-3-

40 yl)naphthalen-2-ol

41 6-(benzo[b]thiophen-2-yl)-N-(l, 2,2,6, 6-pentamethylpiperidin-4-yl)pyridazin-3-amine

N-allyl-3-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperid in-4-yl)amino)pyridazin-3-

42 yl)benzamide

2- (6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridazin -3-yl)-5-(lH-pyrazol-l-

43 yl)phenol

5-(5-methyl-oxazol-2-yl)-2-(6-(methyl-(2,2,6,6-tetramethylpi peridin-4-yl)-amino)-

44 pyridazin-3-yl)phenol

5-(4-hydroxymethyl)-lH-pyrazole-l-yl)-2-(6-(methyl(2,2,6,6-t etramethylpiperidin-4-

45 yl)amino)pyridazin-3-yl)phenol

5-(lH-imidazol-l-yl)-2-(6-(methyl(2,2,6,6-tetramethylpiperid in-4-yl)amino)pyridazin-

46 3-yl)phenol

5-(4-amino-lH-pyrazole-l-yl)-2-(6-(methyl(2,2,6,6-tetramethy lpiperidin-4-

47 yl)amino)pyridazin-3-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(lH-pyrazol-4-

48 yl)phenol

5-(3-amino- lH-pyrazol- 1 -yl)-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-

49 yl)amino)pyridazin-3-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(l-(2-

50 morpholino-ethyl)- lH-pyrazol-4-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(l-methyl-lH-

51 pyrazol-4-yl)phenol

5-(5-amino-lH-pyrazol-l-yl)-2-(6-(methyl-(2,2,6,6-tetramethy lpiperidin-4-

52 yl)amino)pyridazin-3-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-4-(lH-pyrazol-l- 53 ¹ yl)phenol

2-((6-((2-hydroxy-ethyl)-(2,2,6,6-tetramethylpiperidin-4-yl) -amino)-pyridazin-3-yl)-5-

54 pyrazol-l-yl)phenol

55 2-(6-(piperidin-4-yloxy)pyridazin-3-yl)-5-(lH-pyrazol-l-yl)p henol

2-(6-(((2S,4R,6R)-2,6-dimethylpiperidin-4-yl)oxy)pyridazin-3 -yl)-5-(lH-pyrazol-l-

56 yl)phenol

57 2-(6-((-2,6-dimethylpiperidin-4-yl)oxy)pyridazin-3-yl)-5-(lH -pyrazol-l-yl)phenol

58 5-(lH-pyrazol-l-yl)-2-(6-(pyrrolidin-3-yl-oxy)pyridazin-3-yl )phenol

59 2-(6-(((2S,4S)-2-methylpiperidin-4-yl)oxy)pyridazin-3-yl)-5- (lH-pyrazol-l-yl)phenol

60 (5-(lH-pyrazol-l-yl)-2-(6-(pyrrolidin-3-ylmethoxy)pyridazin- 3-yl)phenol Cpd Name

61 2-(6-((3 -fluoropiperidin-4-yl)oxy)pyridazin-3 -yl)-5 -( 1 H-pyrazol- 1 -yl)phenol

2-(6-( 1,2,2,6, 6-pentamethyl-piperidin-4-yl-oxy)-pyridazin-3-yl)-5-(lH-pyra zol-l-

62 yl)phenol

63 5-lH-pyrazol-l-yl-2-(6-(2,2,6,6-tetramethylpiperidin-4-yl-ox y)-pyridazin-3-yl)phenol

64 5-(lH-pyrazol-4-yl)-2-(6-((2,2,6,6-tetramethylpiperidin-4-yl )oxy)pyridazin-3-yl)phenol 65 ¹ 2-(6-piperazin-l-yl-pyridazin-3-yl)-5-(lH-pyrazol-l-yl)pheno l

66 3-(6-(azetidin-3-ylamino)-pyridazin-3-yl)naphthalen-2-ol

67 2-(6-(azetidin-3-ylamino)pyridazin-3-yl)-5-(lH-pyrazol-l-yl) phenol

68 2-(6-(3,5-dimethylpiperazin-l-yl)pyridazin-3-yl)-5-(lH-pyraz ol-l-yl)phenol

2-(6-(7-methyl-2,7-diazaspiro[4.4]nonan-2-yl)pyridazin-3-yl) -5-(lH-pyrazol-l-

69 yl)phenol

70 2-(6-(l,4-diazepan-l-yl)pyridazin-3-yl)-5-(lH-pyrazol-l-yl)p henol

71 2-(6-(4-(2-hydroxyethyl)piperazin-l-yl)pyridazin-3-yl)-5-(lH -pyrazol-l-yl)phenol

72 2-(6-(3,6-diazabicyclo[3.2.1]octan-3-yl)pyridazin-3-yl)-5-(l H-pyrazol-l-yl)phenol

73 2-(6-(2,7-diazaspiro[3.5]nonan-7-yl)pyridazin-3-yl)-5-(lH-py razol-l-yl)phenol

74 2-(6-(3-(hydroxymethyl)piperazin-l-yl)pyridazin-3-yl)-5-(lH- pyrazol-l-yl)phenol

75 2-(6-(l,7-diazaspiro[4.4]nonan-7-yl)pyridazin-3-yl)-5-(lH-py razol-l-yl)phenol

76 2-(6-(4-amino-4-methylpiperidin-l-yl)pyridazin-3-yl)-5-(lH-p yrazol-l-yl)phenol

77 2-(6-(3-(dimethylamino)piperidin-l-yl)pyridazin-3-yl)-5-(lH- pyrazol-l-yl)phenol

2-(6-( 1,2,2,6, 6-pentamethylpiperidin-4-ylamino)-pyridazin-3-yl)-5-lH-pyraz ol-l-yl-

78 phenol

79 2-(6-(3,3-dimethylpiperazin-l-yl)pyridazin-3-yl)-5-(lH-pyraz ol-l-yl)phenol

2-(6-(7-(2-hydroxyethyl)-2,7-diazaspiro[4.4]-nonan-2-yl)pyri dazin-3-yl)-5-(lH-pyrazol-

80 l-yl)phenol

2- (6-((3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(lH)-yl)pyridaz in-3-yl)-5-(lH-

81 pyrazol-l-yl)phenol

82 ¹ 3-(6-(piperazin- l-yl)pyridazin-3-yl)naphthalene-2,7-diol

83 5-( lH-pyrazol- 1 -yl)-2-(6-( 1 ,2,3 ,6-tetrahydropyridin-4-yl)pyridazin-3-yl)phenol

84 2-(6-piperidin-4-yl-pyridazin-3-yl)-5- lH-pyrazol- 1-yl-phenol

85 3-(6-(l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl)naphthal en-2-ol

86 ¹ 3-(6-(l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl)naphthal ene-2,7-diol

3- (6-(2,2,6,6-tetramethyl-l,2,3,6-tetrahydropyridin-4-yl)pyrid azin-3-yl)naphthalene-2,7- 87 diol

88 ¹ 3-(6-(l-methyl-l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl )naphthalene-2,7-diol

89 ¹ 3-(6-(piperidin-4-yl)pyridazin-3-yl)naphthalene-2,7-diol

90 3-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)pyridazin-3-yl) naphthalene-2,7-diol Cpd Name

3-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)naphthalene-2,7-

91 diol

92 3-(6-((2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridazin-3-y l)naphthalene-2,7-diol tert-butyl (3-((7-hydroxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-

93 yl)amino)pyridazin-3-yl)naphthalen-2-yl)oxy)propyl)carbamate

7-(3-amino-propoxy)-3-(6-(methyl-(2,2,6,6-tetramethylpiperid in-4-yl)-amino)-

94 pyridazin-3-yl)naphthalen-2-ol

N-(3-((7-hydroxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4 -yl)amino)pyridazin-3-

95 yl)naphthalen-2-yl)oxy)propyl)acetamide

7-(3-hydroxypropoxy)-3-(6-(methyl(2,2,6,6-tetramethylpiperid in-4-yl)amino)pyridazin-

96 3-yl)naphthalen-2-ol

7-(3-methoxypropoxy)-3-(6-(methyl(2,2,6,6-tetramethylpiperid in-4-yl)amino)pyridazin-

97 3-yl)naphthalen-2-ol

7-(2-morpholinoethoxy)-3-(6-((2,2,6,6-tetramethylpiperidin-4 -yl)oxy)pyridazin-3-

98 yl)naphthalen-2-ol

99 3-(6-(piperidin-4-ylmethyl)pyridazin-3-yl)naphthalen-2-ol

5-(lH-pyrazol-l-yl)-2-(6-((2,2,6,6-tetramethylpiperidin-4-yl )methyl)pyridazin-3-

100 yl)phenol

3-methoxy-2-(6-(methyl(2,2,6-trimethylpiperidin-4-yl)amino)p yridazin-3-yl)-5-(5-

101 methyloxazol-2-yl)phenol

2- (6-((6S)-6-((S)-l-hydroxyethyl)-2,2-dimethylpiperidin-4-ylox y)pyridazin-3-yl)-5-

102 (lH-pyrazol-l-yl)phenol

7-hydroxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-yl)-2-

103 naphthonitrile

3- (6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridazin -3-yl)-7-

104 (piperidinylmethyl)naphthalen-2-ol

3-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-7-

105 (pyrrolidinylmethyl)naphthalen-2-ol

l-bromo-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-

106 yl)naphthalene-2,7-diol

l-chloro-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-

107 yl)naphthalene-2,7-diol

7-methoxy-3-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

108 yl)naphthalene-2-ol

7-methoxy-3-(6-(methyl(l,2,2,6,6-pentamethylpiperidin-4-yl)a mino)pyridazin-3-

109 yl)naphthalen-2-ol

7-(3,6-dihydro-2H-pyran-4-yl)-3-(6-(methyl(2,2,6,6-tetrameth ylpiperidin-4-

110 yl)amino)pyridazin-3-yl)naphthalen-2-ol Cpd Name

3-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-7-(tetra ydro-2H-

111 pyran-4-yl)naphthalene-2-ol

7-(difluoromethyl)-3-(6-(methyl(2,2,6,6-tetramethylpiperidin -4-yl)amino)pyridazin-3-

112 yl)naphthalen-2-ol

7-((4-hydroxy-2-methylbutan-2-yl)oxy)-3-(6-(methyl(2,2,6,6-t etramethylpiperidin-4-

113 yl)amino)pyridazin-3-yl)naphthalen-2-ol

7-(3-hydroxy-3-methylbutoxy)-3-(6-(methyl(2,2,6,6-tetramethy lpiperidin-4-

114 yl)amino)pyridazin-3-yl)naphthalen-2-ol

2- (6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridazin -3-yl)-5-(lH-pyrazol-4-

115 yl)benzene-l,3-diol

3- methoxy-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-yl)-5-

116 (lH-pyrazol-4-yl)phenol

5-(lH-pyrazol-4-yl)-2-(6-((2,2,6,6-tetramethylpiperidin-4-yl )amino)pyridazin-3-yl)-3-

117 (trifluoromethoxy)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(l-methyl-lH-

118 pyrazol-4-yl)-3-(trifluoromethoxy)phenol

2- (6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridazin -3-yl)-5-(lH-pyrazol-4-

119 yl)-3-(trifluoromethoxy)phenol

4- (3-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)pyridazin-3-yl)-5-

120 (trifluoromethoxy)phenyl)-l-methylpyridin-2(lH)-one

3- methoxy-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-yl)-5-(l-

121 methyl- lH-pyrazol-4-yl)phenol

3-methoxy-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-yl)-5-

122 (5,6 ,7 8 -tetrahydroimidazo [ 1 ,2- a] pyridin-3 - yl)phenol

3-methoxy-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-yl)-5-

123 (pyridine-3-yl)phenol

5- (l-cyclopentyl-lH-pyrazol-4-yl)-3-methoxy-2-(6-(methyl(2,2,6 ,6-

124 tetramethylpiperidin-4-yl)amino)pyridazin-3-yl)phenol

3 5-dimethoxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)a mino)pyridazin-3-yl)-

125 (l,l'-biphenyl)-3-ol

3-(benzyloxy)-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl )amino)pyridazin-3-yl)-5-

126 (5-methyloxazol-2-yl)phenol

3-ethoxy-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-5-(5-

127 methyloxazol-2-yl)phenol

3-(cyclopropylmethoxy)-2-(6-(methyl(2,2,6,6-tetramethylpiper idin-4-yl)amino)-

128 pyridazin-3-yl)-5-(5-methyloxazol-2-yl)phenol

2-methyl-5-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-lH-

129 benzo[d]imidazol-6-ol

130 5-chloro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)phenol Cpd Name

5-(lH-pyrazol-l-yl)-2-(6-((2,2,6,6-tetramethylpiperidin-4-yl )amino)pyridazin-3-

131 yl)phenol

132 3-hydroxy-4-(6-((2,2,6,6-tetramethylpiperidin-4-yl)amino)pyr idazin-3-yl)benzonitrile

133 2-(6-((2,2-dimethylpiperidin-4-yl)oxy)pyridazin-3-yl)-5-(lH- pyrazol-l-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyri dazin-3-yl)-4-(lH-pyrazol-4-

134 yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridin -3-yl)-4-(4, 5,6,7-

135 tetrahydropyrazolo[l,5-a]pyridin-3-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-4-(4, 5,6,7-

136 tetrahydropyrazolo[ 1 ,5-a]pyrazin-3-yl)phenol

4-(lH-indol-2-yl)-2-(6-(methyl(2,2,6,6-tetramethylpiperidin- 4-yl)amino)pyridazin-3-

137 yl)phenol

4-(cyclopent-l-en-l-yl)-2-(6-(methyl(2,2,6,6-tetramethylpipe ridin-4-

138 yl)amino)pyridazin-3-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-4-(lH-pyrazol-3-

139 yl)phenol

4-(4-hydroxy-3-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl) amino)pyridazin-3-

140 yl)phenyl)pyridin-2-ol

4-(4-hydroxy-3-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)py ridazin-3-yl)phenyl)-l-

141 methylpyridin-2(lH)-one

4- (4-hydroxy-3-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)pyri dazin-3-

142 yl)phenyl)pyridin-2-ol

5- (lH-indazol-7-yl)-2-(6-(methyl(2,2,6,6-tetramethylpiperidin- 4-yl)amino)pyridazin-3-

143 yl)phenol

4-chloro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-5-(lH-

144 pyrazol-4-yl)phenol

4- fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-yl)-5-(lH-

145 pyrazol-4-yl)phenol

5- fluoro-4-(lH-imidazol-4-yl)-2-(6-(methyl(2,2,6,6-tetramethyl piperidin-4-

146 yl)amino)pyridazin-3-yl)phenol

5-fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-4-(lH-

147 pyrazol-4-yl)phenol

5- fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-yl)-4-(lH-

148 pyrazol-5-yl)phenol

6- hydroxy-5-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-yl)-2,3-

149 dihydro-lH-inden-l-one

6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-l,4-

150 dihydroindeno [ 1 ,2-c] - 1 H-pyrazol-7-ol Cpd Name

6-hydroxy-5-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-yl)-2,3- 151 ¹ dihydro-lH-inden-1 -one oxime

5-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-2,3-dihydro-lH- 152 indene-l,6-diol

2- amino-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)p yridazin-3-yl)-8H- 153 ¹ indeno[l,2-d]thiazol-5-ol

9-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5,6- 154 ¹ dihydroimidazo[5, l-a]isoquinolin-8-ol

4-hydroxy-3-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-yl)-N-((l-

155 methyl- lH-pyrazol-4-yl)methyl)benzamide

4- (4-(hydroxymethyl)-lH-pyrazol-l-yl)-2-(6-(methyl(2,2,6,6-tet ramethylpiperidin-4-

156 yl)amino)pyridazin-3-yl)phenol

5- (lH-pyrazol-4-yl)-2-(6-((2,2,6,6-tetramethylpiperidin-4-yl)m ethyl)pyridazin-3-

157 yl)phenol

6- (3-(benzyloxy)isoquinolin-6-yl)-N-methyl-N-(2,2,6,6-tetramet hylpiperidin-4-

158 yl)pyridazin-3-amine

6-(l-(benzyloxy)isoquinolin-7-yl)-N-methyl-N-(2,2,6,6-tetram ethylpiperidin-4-

159 yl)pyridazin-3-amine

3- fluoro-5-(2-methoxypyridin-4-yl)-2-(6-(methyl(2,2,6,6-tetram ethylpiperidin-4- 160 ¹ yl)amino)pyridazin-3-yl)phenol

4- (3-fluoro-5-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidi n-4-yl)amino)pyridazin- 161 ¹ 3-yl)phenyl)pyridin-2(lH)-one

4- (3-fluoro-5-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidi n-4-yl)amino)pyridazin- 162 ¹ 3 -yl)phenyl)- 1 -methylpyridin-2( 1 H)-one

5- (3-fluoro-5-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidi n-4-yl)amino)pyridazin- 163 ¹ 3 -yl)phenyl)- 1 -methylpyridin-2( 1 H)-one

3-fluoro-5-(lH-pyrazol-4-yl)-2-(6-((2,2,6,6-tetramethylpiper idin-4-yl)oxy)pyridazin-3- 164 ¹ yl)phenol

5-chloro-3-fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin- 4-yl)amino)pyridazin-3- 165 ¹ yl)phenol

3-fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-5-(lH- 166 ¹ pyrazol-4-yl)phenol

3-fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-5-(l- 167 ¹ methyl- lH-pyrazol-4-yl)phenol

5-(5-methoxypyridin-3-yl)-2-(6-(methyl(2,2,6,6-tetramethylpi peridin-4-

168 yl)amino)pyridazin-3-yl)phenol

5-(3-hydroxy-4-(6-methyl(2,2,6,6-tetramethylpiperidin-4-yl)a mino)pyridazin-3-

169 yl)phenyl)pyridin-2-ol Cpd Name

4- (3-hydroxy-4-(6-methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

170 yl)phenyl)pyridin-2-ol

5- (6-methoxypyridin-3-yl)-2-(6-(methyl(2,2,6,6-tetramethylpipe ridin-4-

171 yl)amino)pyridazin-3-yl)phenol

5-(3-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl) amino)pyridazin-3-

172 yl)phenyl)-3-(trifluoromethyl)pyridin-2-ol

5-(3-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl) amino)pyridazin-3-

173 yl)phenyl)- 1 -methylpyridin-2( lH)-one

4- (3-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)pyridazin-3-

174 yl)phenyl)- 1 -methylpyridin-2( lH)-one

5- (2-methoxypyridin-4-yl)-2-(6-(methyl(2,2,6,6-tetramethylpipe ridin-4-

175 yl)amino)pyridazin-3-yl)phenol

4- (3-hydroxy-4-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)pyri dazin-3-

176 yl)phenyl)pyridin-2-ol

5- (6-(dimethylamino)pyridin-3-yl)-2-(6-(methyl(2,2,6,6-tetrame thylpiperidin-4-

177 yl)amino)pyridazin-3-yl)phenol

4- (3-hydroxy-4-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)pyri dazin-3-yl)phenyl)-l-

178 methylpyridin-2(lH)-one

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(pyrimidin-5-

179 yl)phenol

5- (3-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)pyridazin-3-

180 yl)phenyl)pyridin-3-ol

1- cyclopropyl-4-(3-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpip eridin-4-

181 yl)amino)pyridazin-3-yl)phenyl)pyridin-2(lH)-one

2- (6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridazin -3-yl)-5-(l,2,3,6-

182 tetrahydropyridin-4-yl)phenol

5-(cyclopent-l-en-l-yl)-2-(6-(methyl(2,2,6,6-tetramethylpipe ridin-4-

183 yl)amino)pyridazin-3-yl)phenol

5-(3,6-dihydro-2H-pyran-4-yl)-2-(6-(methyl(2,2,6,6-tetrameth ylpiperidin-4-

184 yl)amino)pyridazin-3-yl)phenol

5-(imidazo[l,5-a]pyridin-7-yl)-2-(6-(methyl(2,2,6,6-tetramet hylpiperidin-4-

185 yl)amino)pyridazin-3-yl)phenol

5-(imidazo[l,2-a]pyridin-7-yl)-2-(6-(methyl(2,2,6,6-tetramet hylpiperidin-4-

186 yl)amino)pyridazin-3-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(2-

187 methylpyridin-4-yl)phenol

5-(lH-imidazol-2-yl)-2-(6-(methyl(2,2,6,6-tetramethylpiperid in-4-yl)amino)pyridazin-

188 3-yl)phenol Cpd Name

5-(lH-imidazol-4-yl)-2-(6-(methyl(2,2,6,6-tetramethylpiperid in-4-yl)amino)pyridazin-

189 3-yl)phenol

5-(imidazo[l,2-a]pyrazin-3-yl)-2-(6-(methyl(2,2,6,6-tetramet hylpiperidin-4-

190 yl)amino)pyridazin-3-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(5, 6,7,8-

191 tetrahydroimidazo[ 1 ,2-a]pyrazin-3-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(4-methyl-lH-

192 imidazol-2-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(l-methyl-lH-

193 imidazol-4-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(l-methyl-lH-

194 imidazol-5-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(4-nitro-lH-

195 imidazol-2-yl)phenol

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(2-methyl-lH-

196 imidazol-4-yl)phenol

5- (l,2-dimethyl H-imidazol-4-yl)-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4 -

197 yl)amino)pyridazin-3-yl)phenol

1- (3-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)pyridazin-3-

198 yl)phenyl)-lH-pyrazole-4-carboxamide

2- (6-((3aR,6aS)-5-(2-hydroxyethyl)hexahydropyrrolo[3,4-c]pyrro l-2(lH)-yl)pyridazin-

199 3-yl)-5-(lH-pyrazol-4-yl)phenol

2-(6-((3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(lH)-yl)pyrid azin-3-yl)-5-(lH-

200 pyrazol-4-yl)phenol

2-(6-((3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol-2(lH)- yl)pyridazin-3-yl)-5-

201 (lH-pyrazol-4-yl)phenol

4-(3-hydroxy-4-(6-(5-methylhexahydropyrrolo[3,4-c]pyrrol-2(l H)-yl)pyridazin-3-

202 yl)phenyl)- 1 -methylpyridin-2( lH)-one

4-(3-hydroxy-4-(6-((3aR,6aR)-l-methylhexahydropyrrolo[3,4-b] pyrrol-5(lH)-

203 yl)pyridazin-3-yl)phenyl)-l-methylpyridin-2(lH)-one

204 2-(6-(2,7-diazaspiro[4.5]decan-2-yl)pyridazin-3-yl)-5-(lH-py razol-4-yl)phenol

4-(4-(6-(2,7-diazaspiro[4.5]decan-2-yl)pyridazin-3-yl)-3-hyd roxyphenyl)-l-

205 methylpyridin-2(lH)-one

206 2-(6-(methyl-(2,2,6,6-tetramethylpiperidin-4-yl)-amino)-pyri dazin-3-yl)phenol

207 6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)quinolin-7-ol

208 6-(6-(methyl(l,2,2,6,6-pentamethylpiperidin-4-yl)amino)pyrid azin-3-yl)quinolin-7-ol

6- (6-((3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol-2(lH)-yl )pyridazin-3-

209 yl)quinolin-7-ol Cpd Name

2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)quinolin

210 7-ol

211 7-(6-(methyl(l,2,2,6,6-pentamethylpiperidin-4-yl)amino)pyrid azin-3-yl)isoquinolin-6-ol

212 7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)isoquinolin-6-ol

213 7-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)pyridazin-3-yl) isoquinoline-6-ol

7-(6-((3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol-2(lH)- yl)pyridazin-3-

214 yl)isoquinolin-6-ol

1- cyclopropyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)a mino)pyridazin-3-

215 yl)isoquinolin-6-ol

7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)isoquinoline-l,6-

216 diol

6- hydroxy-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-

217 yl)isoquinoline- 1 -carbonitrile

218 6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)isoquinolin-7-ol

219 8-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)quinolin-7-ol

220 6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)quinolin-6-ol

2- methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-yl)quinolin-

221 6-ol

3- chloro-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-yl)quinolm

222 7-ol

3-bromo-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-yl)quinolm

223 7-ol

7- hydroxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-

224 yl)quinoline-3 -carbonitrile

6- (6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridazin -3-yl)-3-(l-methyl-lH-

225 imidazol-4-yl)quinolin-7-ol

3-(lH-imidazol-l-yl)-6-(6-(methyl(2,2,6,6-tetramethylpiperid in-4-yl)amino)pyridazin- 226 ¹ 3-yl)quinolin-7-ol

227 6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)quinoline-3,7-dio

3-ethyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)pyridazin-3-yl)quinolin-

228 7-ol

3-isopropyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)a mino)pyridazin-3-

229 yl)quinolin-7-ol

7- hydroxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-

230 yl)quinolin-2(lH)-one

7-hydroxy-l-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin -4-yl)amino)pyridazin-3- 231 ¹ yl)quinolin-2(lH)-one Cpd Name

4-methoxy-2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin -4-yl)amino)pyridazm

232 yl)quinolin-7-ol

2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-4-

233 (pyrrolidin- 1 -yl)quinolin-7-ol

2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-4-

234 morpholinoquinolin-7-ol

4-(dimethylamino)-2-methyl-6-(6-(methyl(2,2,6,6-tetramethylp iperidin-4-

235 yl)amino)pyridazin-3-yl)quinolin-7-ol

4-ethoxy-2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin- 4-yl)amino)pyridazin-

236 yl)quinolin-7-ol

2- methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-yl)-4-(l-

237 methyl- lH-pyrazol-4-yl)quinolin-7-ol

4- methoxy-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3- 238 ¹ yl)quinolin-6-ol

239 ¹ 7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)quinoxalin-6-ol

6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyri dazin-3-yl)-3-(tetrahydro-2H-

240 pyran-4-yl)quinolin-7-ol

3- cmoro-7-(6-(methyl(2,2,6,6-tetramethyl^^

241 6-ol

3-bromo-7-(6-(methyl(2,2,6,6-tetramethy^

242 6-ol

3-methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)quinolm

243 6-ol

5- bromo-3-methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-y l)amino)pyridazi^

244 yl)quinolin-6-ol

6- hydroxy-l-methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4 -yl)amino)pyridazin-3-

245 yl)quinolin-4(lH)-one

2,3-dimethyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl) amino)pyridazin-3-

246 yl)quinolin-6-ol

2- methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-

247 yl)quinoxalin-6-ol

3- methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-

248 yl)quinoxalin-6-ol

4- methoxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-

249 yl)quinolin-7-ol

4-(azetidin-l-yl)-2-methyl-6-(6-(methyl(2,2,6,6-tetramethylp iperidin-4-

250 yl)amino)pyridazin-3-yl)quinolin-7-ol

7- hydroxy-2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4 -yl)amino)pyridazin-3-

251 yl)quinolone-4-carbonitrile Cpd Name

4-cyclopropyl-2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiper idin-4-

252 yl)amino)pyridazin-3-yl)-quinolin-7-ol

4-(3,6-dihydro-2H-pyran-4-yl)-2-methyl-6-(6-(methyl(2,2,6,6- tetramethylpiperidin-4-

253 yl)amino)pyridazin-3-yl)quinolin-7-ol

2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-4- 254 ¹ (tetrahydro-2H-pyran-4-yl)quinolin-7-ol

2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-4- 255 (oxetan-3-yl)quinolin-7-ol

4-(dimethylamino)-6-(6-(methyl(2,2,6,6-tetramethylpiperidin- 4-yl)amino^

256 ¹ yl)-quinolin-7-ol

7-hydroxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

257 yl)quinazolin-4(lH)-one

258 6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)quinazolin-7-ol

7-hydroxy-l-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperi din-4-yl)amino)pyridazm

259 yl)-3 ,4-dihydroquinolin-2( lH)-one

2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-

260 yl)quinazolin-7-ol

7-hydroxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

261 yl)isoquinoline- 1 -carbonitrile

7-hydroxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

262 yl)quinoline-2-carbonitrile

6-hydroxy-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

263 yl)quinolin-2-carbonitrile

6- hydroxy-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-

264 yl)isoquinoline- 1 -carboxamide

7- hydroxy-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-

265 yl)quinolin-2-carboxamide

6-hydroxy-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

266 yl)quinoline-2-carboxamide

methyl 6-hydroxy-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

267 yl)quinoline-2-carboxylate

268 6-hydroxy-7-(6-(piperazin-l-yl)pyridazin-3-yl)quinoline-2-ca rbonitrile

269 7-hydroxy-6-(6-(piperazin-l-yl)pyridazin-3-yl)quinoline-2-ca rbonitrile

270 7-(6-(piperazin- l-yl)pyridazin-3-yl)isoquinolin-6-ol

271 7-(6-(l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl)quinolin -6-ol

l-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-

272 yl)isoquinolin-7-ol

l-methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-

273 yl)isoquinolin-6-ol Cpd Name

l,3-dimethyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl) amino)pyridazin-3-

274 yl)isoquinolin-6-ol

7-hydroxy-3-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin -4-yl)amino)pyridazin-3-

275 yl)isoquinoline- 1 -carbonitrile

1- amino-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)p yridazin-3-

276 yl)isoquinolin-6-ol

7-hydroxy-l,3-dimethyl-6-(6-(methyl(2,2,6,6-tetramethylpiper idin-4-

277 yl)amino)pyridazin-3-yl)quinazoline-2,4(lH,3H)-dione

6-hydroxy-5-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-

278 yl)benzo[d]oxazol-2(3H)-one

2- methyl-5-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-yl)-2H-

279 indazol-6-ol

1- methyl-5-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-yl)-lH-

280 indazol-6-ol

6- hydroxy-2-methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4 -yl)amino)pyridazin-3- 281 ¹ yl)isoquinolin-l(2H) -one

2- ethyl-6-hydroxy-7-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy )pyridazin-3-

282 yl)isoquinolin- 1 (2H)-one

l-ethoxy-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-

283 yl)isoquinolin-6-ol

284 7-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)pyridazin-3-yl) isoquinoline-l,6-diol

7- (6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-pyridazi n-3-yl)-3-

285 phenylisoquinolin-6-ol

3- methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-

286 yl)isoquinolin-6-ol

3-cyclopropyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl )amino)pyridazin-3-

287 yl)isoquinolin-6-ol

3-isopropyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)a mino)pyridazin-3-

288 yl)isoquinolin-6-ol

289 3-propyl-7-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)-pyrid azin-3-yl)isoquinolin-6-ol

3-isopropyl-7-(6-((2,2,6,6-tetramethylpiperidin-4-yl)oxy) -pyridazin-3-yl)isoquinolin-6-

290 ol

291 3-methyl-7-(6-(piperazin-l-yl)pyridazin-3-yl)isoquinolin-6-o l

6-(3-(benzyloxy)isoquinolin-6-yl)-N-methyl-N-(2,2,6,6-tetram ethylpiperidin-4-

292 yl)pyridazin-3-amine

3-chloro-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)quinolin

293 7-ol

3-isopropyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)a mino)pyridazin-3-

294 yl)quinolin-7-ol Cpd Name

3- methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-

295 yl)quinoxalin-6-ol

4- chloro-2-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4- yl)amino)pyridazin-3-

296 yl)quinolin-7-ol

4- chloro-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-yl)quinolm

297 6-ol

300 7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)quinolin-6-ol

5- (2-methoxy-4-(lH-pyrazol-l-yl)phenyl)-N-methyl-N-(2,2,6,6-te tramethylpiperidin-4-

301 yl)-l,3,4-thiadiazol-2-amine

6- (5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4-th iadiazol-2-yl)naphthalen-

302 2-ol

5-(2-methoxyquinolin-3-yl)-N-methyl-N-(2,2,6,6-tetramethylpi peridin-4-yl)- 1,3,4-

303 thiadiazol-2-amine

5-(3-methoxy-naphthalen-2-yl)-N-methyl-N-(2,2,6,6-tetramethy lpiperidin-4-yl)- 1,3,4-

304 thiadiazol-2-amine

5-(2-methoxy-4-(lH-pyrazol-lyl)phenyl)-N-(l, 2,2,6, 6-pentamethylpiperidin-4-yl)-

305 l,3,4-thiadiazol-2-amine

5-(2-methoxy-4-(l-methyl-lH-pyrazol-4-yl)phenyl)-N-methyl-N- (2,2,6,6-

306 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2-methoxy-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-(2,2,6,6- tetramethylpiperidin-4-

307 yl)-l,3,4-thiadiazol-2-amine

4- (3-methoxy-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)-l,3,4-thiadiazol-2-

308 yl)phenyl)- 1 -methylpyridin-2( lH)-one

5- (3-methoxy-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)-l,3,4-thiadiazol-2-

309 yl)phenyl)pyridin-2-ol

5-(3-methoxy-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl) amino)-l,3,4-thiadiazol-2-

310 yl)phenyl)- 1 -methylpyridin-2( lH)-one

N-methyl-5-(2-methyl-4-(l-methyl-lH-pyrazol-4-yl)phenyl)-N-( 2,2,6,6-

311 tetramethylpiperidin-4-yl)-l,3,4-thiadiazol-2-amine

1 -methyl-4-(4-(5-(methyl (2,2,6, 6-tetramethylpiperidin-4-yl)amino)- 1,3, 4-thiadiazol-2-

312 yl)-3-(trifluoromethoxy)phenyl)pyridin-2(lH)-one

5-(4-(3,5-dimethyl-lH-pyrazol-4-yl)-2-methoxyphenyl)-N-methy l-N-(2,2,6,6-

313 tetramethylpiperidin-4-yl)-l,3,4-thiadiazol-2-amine

5-(2-methoxy-4-(l-methyl-lH-pyrazol-4-yl)phenyl)-N-methyl-N- (2,2,6,6-

314 tetramethylpiperidin-4-yl)-l,3,4-thiadiazol-2-amine

2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)- 1,3,4, -thiadiozol-2-yl-5-(l-

315 methyl- lH-pyrazol-4-yl)phenol

2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)- 1,3,4, -thiadiozol-2-yl-5-(lH-

316 pyrazol-l-yl)phenol Cpd Name

5-(3-hydroxy-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl) amino)-l,3,4-thiadiazol-2-

317 yl)phenyl)- 1 -methylpyridin-2( lH)-one

4- (3-hydroxy-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)-l,3,4-thiadiazol-2-

318 yl)phenyl)- 1 -methylpyridin-2( lH)-one

5- (3-hydroxy-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)-l,3,4-thiadiazol-2-

319 yl)phenyl)pyridin-2-ol

3-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4- thiadiazol-2-

320 yl)naphthalene-2,7-diol

3-(5-((3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(lH)-yl)-l,3, 4-thiadiazol-2-

321 yl)naphthalene-2,7-diol

3-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4- thiadiazol-2-yl)naphthalen- 322 ¹ 2-ol

3-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4- thiadiazol-2-yl)quinolin-2-

323 ol

2- (5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) ,3,4-thiadiazol-2-yl)-4-(lH-

324 pyrazol-l-yl)phenol

5-(2-chloro-4-(l-methyl-lH-pyrazol-4-yl)phenyl)-N-methyl-N-( 2,2,6,6-

325 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

3- chloro-2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) -l,3,4-thiadiazol-2-yl)-

326 5-(l-methyl-lH-pyrazol-4-yl)phenol

5-(2-chloro-4-(l-methyl-lH-pyrazol-4-yl)phenyl)-N-(2,2,6,6-t etramethylpiperidin-4-yl)-

327 l,3,4-thiadiazol-2-amine

3-methoxy-2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)-l,3,4-thiadiazol-2-

328 yl)-5-methyloxazol-2-yl)phenol

2- (2-methoxy-4-(lH-pyrazol-l-yl)phenyl)-5-( 1,2,3, 6-tetrahydropyridin-4-yl)- 1,3,4-

329 thiadiazole

330 2-(5-(piperazin-l-yl)-l,3,4-thiadiazol-2-yl)-5-(lH-pyrazol-l -yl)phenol

5- (7-methoxyquinolin-6-yl)-N-methyl-N-(2,2,6,6-tetramethylpipe ridin-4-yl)- 1,3,4-

331 thiadiazole-2-amine

6- (5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4-th iadiazol-2-yl)quinolin-7-

332 ol

3- methoxy-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )-l,3,4-thiadiazol-2-

333 yl)benzonitrile

3-fluoro-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)-l,3,4-thiadiazol-2-

334 yl)benzonitrile

methyl-3-fluoro-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4- yl)amino)-l,3,4-thiadiazol-

335 2-yl)benzoate

5-(2-methoxy-4-(3-(methylamino)-lH-pyrazol-l-yl)phenyl)-N-me thyl-N-(2,2,6,6-

336 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine Cpd Name

7-methoxy-6-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)-l,3,4-thiadiazol-2-

337 yl)quinoline-2-carbonitrile

4-(3-methoxy-4-(5-((2,2,6,6-tetramethylpiperidin-4-yl)oxy)-l ,3,4-thiadiazol-2-

338 yl)phenyl)- 1 -methylpyridin-2( lH)-one

4- (3-chloro-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)-l,3,4-thiadiazol-2-

339 yl)phenyl)- 1 -methylpyridin-2( lH)-one

5- (2-chloro-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-(2,2,6,6-tet ramethylpiperidin-4-

340 yl)-l,3,4-thiadiazol-2-amine

5-(2-chloro-4-(4,5,6,7-tetrahydropyrazolo[l,5-a]pyridin-3-yl )phenyl)-N-methyl-N-

341 (2,2,6,6-tetramethylpiperidin-4-yl)-l,3,4-thiadiazol-2-amine

N-methyl-5-(5-(l-methyl-lH-pyrazol-4-yl)pyridin-2-yl)-N-(2,2 ,6,6- 342 ¹ tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

2-(2-chloro-4-(l-methyl-lH-pyrazol-4-yl)phenyl)-5-((2,2,6,6- tetramethylpiperidin-4-

343 yl)oxy-l,3,4-thiadiazole

5-(2-chloro-4-(6-methoxypyridin-3-yl)phenyl)-N-methyl-N-(2,2 ,6,6-

344 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(4-(6-aminopyridin-3-yl)-2-fluorophenyl)-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin-

345 4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2-fluoro-4-(3-methyl-lH-pyrazol-5-yl)phenyl)-N-methyl-N-( 2,2,6,6-

346 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2-fluoro-4-(lH-pyrazol-5-yl)phenyl)-N-methyl-N-(2,2,6,6-t etramethylpiperidin-4-

347 yl)-l,3,4-thiadiazol-2-amine

5-(2,3-difluoro-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin-

348 4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2,3-difluoro-4-(lH-pyrazol-5-yl)phenyl)-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin-

349 4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin-

350 4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2,5-difluoro-4-(lH-pyrazol-5-yl)phenyl)-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin-

351 4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2,6-difluoro-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin-

352 4-yl)- 1 ,3 ,4-thiadiazol-2-amine

2-(2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl)-5-((3aR,6aS)-hexa hydropyrrolo[3,4-

353 c]pyrrol-2( lH)-yl)- 1 ,3 ,4-thiadiazole

5-(2-chloro-5-fluoro-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-( 2,2,6,6-

354 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(3-fluoro-5-(lH-pyrazol-4-yl)pyridin-2-yl)-N-methyl-N-(2,2 ,6,6-tetramethylpiperidin-

355 4-yl)- 1 ,3 ,4-thiadiazol-2-amine Cpd Name

5-(4-(2-aminopyrimidin-4-yl)-2-chlorophenyl)-N-methyl-N-(2,2 ,6,6-

356 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(5-(2-aminopyrimidin-4-yl)-2-chlorophenyl)-N-methyl-N-(2,2 ,6,6-

357 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(4-(2,4-dimethylthiazol-5-yl)-2,5-difluorophenyl)-N-methyl -N-(2,2,6,6-

358 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(4-(2,4-dimethylthiazol-5-yl)-2,3-difluorophenyl)-N-methyl -N-(2,2,6,6-

359 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

4- (3-hydroxy-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)am ino)-l,3,4-thiadiaz

360 yl)-5-(trifluoromethoxy)phenyl)- l-methylpyridin-2(lH)-one

5- (2-fluoro-6-methoxy-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-(2 ,2,6,6-

361 tetramethylpiperidin-4-yl)-l,3,4-thiadiazol-2-amine

2-(2-fluoro-6-methoxy-4-(lH-pyrazol-4-yl)phenyl)-5-((3aR,6aS )-5-

362 methylhexahydropyrrolo [3 ,4-c]pyrrol-2( 1 H)-yl)- 1 ,3 ,4-thiadiazole

5- (2,3-difluoro-6-methoxy-4-(lH-pyrazol-4-yl)phenyl)-N-methyl- N-(2,2,6,6-

363 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

6- methoxy-2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )-l,3,4-thiadiazol-2-

364 yl)-3 ,4-dihydroisoquinolin- 1 -(2H)-one

5-(2-chloro-4-(lH-pyrazol-l-yl)phenyl)-N-methyl-N-(2,2,6,6-t etramethylpiperidin-4-

365 yl)-l,3,4-thiadiazol-2-amine

5-(2-chloro-4-(lH-l,2,3-triazol-l-yl)phenyl)-N-methyl-N-(2,2 ,6,6-tetramethylpiperidin-

366 4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2-chloro-4-(2H-l,2,3-triazol-2-yl)phenyl)-N-methyl-N-(2,2 ,6,6-tetramethylpiperidin-

367 4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2-chloro-4-(lH-l,2,4-triazol-l-yl)phenyl)-N-methyl-N-(2,2 ,6,6-tetramethylpiperidin-

368 4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(4-(3-amino-lH-pyrazol-l-yl)-2-chlorophenyl)-N-methyl-N-(2 ,2,6,6-

369 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

2-(2-chloro-4-(lH-imidazol-l-yl)phenyl)-5-((3aR,6aS)-5-

370 methylhexahydropyrrolo[3,4c]pyrrol-2(lH)-yl)-l,3,4-thiadiazo le

5-(2-chloro-4-(lH-imidazol-l-yl)phenyl)-N-methyl-N-(2,2,6,6- tetramethylpiperidin-4-

371 yl)-l,3,4-thiadiazol-2-amine

5-(2-fluoro-4-(lH-imidazol-l-yl)phenyl)-N-methyl-N-(2,2,6,6- tetramethylpiperidin-4-

372 yl)-l,3,4-thiadiazol-2-amine

5-(2-methoxy-4-(lH-pyrazol-5-yl)phenyl)-N-methyl-N-(2,2,6,6- tetramethylpiperidin-4-

373 yl)-l,3,4-thiadiazol-2-amine

5-(4-(2,4-dimethylthiazol-5-yl)-2-methoxyphenyl)-N-methyl-N- (2,2,6,6-

374 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine Cpd Name

5-(2-methoxy-4-(pyridin-3-yl)phenyl)-N-methyl-N-(2,2,6,6-tet ramethylpiperidin-4-yl)-

375 l,3,4-thiadiazol-2-amine

5-(2-fluoro-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-(2,2,6,6-t etramethylpiperidin-4-

376 yl)-l,3,4-thiadiazol-2-amine

5-(2-methoxy-4-(2-methoxypyridin-4-yl)phenyl)-N-methyl-N-(2, 2,6,6-

377 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

5-(2-methoxy-4-(6-methoxypyridin-3-yl)phenyl)-N-methyl-N-(2, 2,6,6-

378 tetramethylpiperidin-4-yl)- 1 ,3 ,4-thiadiazol-2-amine

2-(2-chloro-4-(l-methyl-lH-pyrazol-4-yl)phenyl)-5-((3aR,6aS) -5-

379 methylhexahydropyrrolo [3 ,4-c]pyrrol-2( 1 H)-yl)- 1 ,3 ,4-thiadiazole

2-(2-chloro-4-(lH-pyrazol-4-yl)phenyl)-5-((3aR,6aS)-5-methyl hexahydropyrrolo[3,4-

380 c]pyrrol-2( lH)-yl)- 1 ,3 ,4-thiadiazole

2-(2-chloro-4-(lH-pyrazol-4-yl)phenyl)-5-((3aR,6aR)-l-methyl hexahydropyrrolo[3,4-

381 b]pyrrol-5(lH)-yl)-l,3,4-thiadiazole

1- (4-(5-(2-chloro-4-(lH-pyrazol-4-yl)phenyl)-l,3,4-thiadiazol- 2-yl)morpholin-2-yl)-

382 N,N-dimethylmethanamine

2- (2-chloro-4-(lH-pyrazol-4-yl)phenyl)-5-(2-methyl-2,7-diazasp iro[4.5]decan-7-yl)-

383 1,3,4-thiadiazole

2-(2-fluoro-4-(lH-pyrazol-4-yl)phenyl)-5-((3aR,6aS)-5-methyl hexahydropyrrolo[3,4-

384 c]pyrrol-2( lH)-yl)- 1 ,3 ,4-thiadiazole

2-(2-methoxy-4-(l-methyl-lH-pyrazol-4-yl)phenyl)-5-(2,6-diaz aspiro[3.5]nonan-2-yl)-

385 1,3,4-thiadiazole

2-(2-methoxy-4-(l-methyl-lH-pyrazol-4-yl)phenyl)-5-(2,7-diaz aspiro[3.5]nonan-2-yl)-

386 1,3,4-thiadiazole

2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4- thiadiazol-2-yl)-5-(lH-

387 pyrazol-l-yl)phenol

5- (3-chloro-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)-l,3,4-thiadiazol-2-

388 yl)phenyl)pyridin-2(lH)-one

2- (5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4-th iadiazol-2-yl)-5-(3-

389 (methylamino)-lH-pyrazol-l-yl)phenol

3- fluoro-2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) -l,3,4-thiadiazol-2-yl)-5-

390 (lH-pyrazol-4-yl)phenol

3,4-difluoro-2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl) amino)-l,3,4-thiadiazol-2-

391 yl)-5-(lH-pyrazol-4-yl)phenol

6- hydroxy-5-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )-l,3,4-thiadiazol-2-

392 yl)-2,3-dihydro- lH-inden- 1-one

2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4- thiadiazol-2-yl)-5-(lH-

393 pyrazol-4-yl)phenol Cpd Name

2-(5-(2,6-diazaspiro[3.5]nonan-2-yl)-l,3,4-thiadiazol-2-yl)- 5-(l-methyl-lH-pyrazol-4-

394 yl)phenol

2- (5-(2,7-diazaspiro[3.5]nonan-2-yl)-l,3,4-thiadiazol-2-yl)-5- (l-methyl-lH-pyrazol-4-

395 yl)phenol

3- fluoro-2-(5-((3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(lH)-y l)-l,3,4-thiadiazol-2- 396 ¹ yl)-5-(lH-pyrazol-4-yl)phenol

3- chloro-2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) -l,3,4-thiadiazol-2-yl)-

397 5-(lH-pyrazol-4-yl)phenol

2-(2-methoxy-4-(lH-pyrazol-l-yl)phenyl)-5-((2,2,6,6-tetramet hylpiperidin-4-

398 yl)methyl)-l,3,4-thiadiazole

2-(2,3-difluoro-4-(lH-pyrazol-4-yl)phenyl)-5-(2,7-diazaspiro [3.5]nonan-2-yl)-l,3,4-

399 thiadiazole

2- (5-(2,7-diazaspiro[3.5]nonan-2-yl)-l,3,4-thiadiazol-2-yl)-3- fluoro-5-(lH-pyrazol-4-

400 yl)phenol

4- methoxy-l-methyl-3-(5-(methyl(2,2,6,6-tetramethylpiperidin-4 -yl)amino)- 1,3,4-

401 thiadiazol-2-yl)quinolin-2( 1 H)-one

4- hydroxy-l-methyl-3-(5-(methyl(2,2,6,6-tetramethylpiperidin-4 -yl)amino)- 1,3,4-

402 thiadiazol-2-yl)quinolin-2( 1 H)-one

3- (5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4-th iadiazol-2-yl)quinolin-

403 2(lH)-one

1- methyl-3-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) -l,3,4-thiadiazol-2-

404 yl)quinolin-2(lH)-one

2- (2-chloro-4-(lH-pyrazol-4-yl)phenyl)-5-((3aR,6aS)-hexahydrop yrrolo[3,4-c]pyrrol- 405 ¹ 2(lH)-yl)-l,3,4-thiadiazole

2-(2-chloro-4-(lH-pyrazol-4-yl)phenyl)-5-(2,7-diazaspiro[4.5 ]decan-2-yl)-l,3,4- 406 ¹ thiadiazole

(R)-(4-(5-(2-chloro-4-(lH-pyrazol-4-yl)phenyl)-l,3,4-thiadia zol-2-yl)piperazin-2- 407 ¹ yl)methanol

2-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4- thiadiazol-2-

408 yl)benzo [b] thiophene- 5 -c arbonitrile

5- (3-chlorobenzo[b]thiophen-2-yl)-N-methyl-N-(2,2,6,6-tetramet hylpiperidin-4-yl)-

409 l,3,4-thiadiazol-2-amine

5-(2-methoxy-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-(2,2,6,6- tetramethylpiperidin-4-

410 yl)-l,3,4-thiadiazol-2-amine

2-{6-[(1 ?,5S)-8-azabicyclo[3.2.1]oct-3-yl(methyl)amino]pyridazin-3-y l}-5-(lH- 411 ¹ pyrazol-4-yl)phenol

2-[6-((1 ?,5S)-8-azabicyclo[3.2.1]oct-3-ylamino)pyridazin-3-yl]-5-(lH -pyrazol-4- 412 ¹ yl)phenol Cpd Name

5-(lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpiperidin-4-yl )amino]pyridazin-3- 413 ¹ yljphenol

5-(l-methyl-lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpiper idin-4-yl)oxy]pyridazin-3- 414 yljphenol

2-[6-((1 ?,5S)-8-azabicyclo[3.2.1]oct-3-yloxy)pyridazin-3-yl]-5-(lH-p yrazol-4- 415 ¹ yl)phenol

5-(5-methyl- lH-pyrazol-4-yl)-2- { 6-[methyl(2,2,6,6-tetramethylpiperidin-4-

416 yl)amino]pyridazin-3-yl}phenol

5-(lH-imidazol-l-yl)-2-{ 6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyridazin-3-

417 yljphenol

5- (5-methyl-lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpiperid in-4-yl)oxy]pyridazin-3-

418 yljphenol

2-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-5-(4-nitro-lH- 419 ¹ pyrazol-l-yl)phenol

6- [2-methoxy-4-(4-nitro-lH-pyrazol-l-yl)phenyl]-N-methyl-N-(2, 2,6,6-

420 tetramethylpiperidin-4-yl)pyridazin-3-amine

5-(4-amino-lH-pyrazol-l-yl)-2-{6-[(2,2,6,6-tetramethylpiperi din-4-yl)oxy]pyridazin-3-

421 yljphenol

2- [6-(l-methyl- 1,2,3, 6-tetrahydropyridin-4-yl)pyridazin-3-yl]-5-(lH-pyrazol-4- 422 ¹ yl)phenol

5- (4-nitro-lH-pyrazol-l-yl)-2-{6-[(2,2,6,6-tetramethylpiperidi n-4-yl)oxy]pyridazin-3- 423 yljphenol

424 ¹ 5-(lH-pyrazol-4-yl)-2-[6-(l,2,3,6-tetrahydropyridin-4-yl)pyr idazin-3-yl]phenol

425 ¹ 2-[6-(l-ethyl-l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl] -5-(lH-pyrazol-4-yl)phenol 426 ¹ 2-{6-[methyl(piperidin-4-yl)amino]pyridazin-3-yl}-5-(lH-pyra zol-4-yl)phenol

427 ¹ 2-[6-(piperidin-4-ylamino)pyridazin-3-yl]-5-(lH-pyrazol-4-yl )phenol

6- [2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6 -tetramethylpiperidin- 428 ¹ 4-yl)pyridazin-3-amine

429 ¹ 2-[6-(8-azabicyclo[3.2.1]oct-2-en-3-yl)pyridazin-3-yl]-5-(lH -pyrazol-4-yl)phenol

6-[2,3-difluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin- 430 ¹ 4-yl)pyridazin-3-amine

3- [2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetrame thylpiperidin-4- 431 ¹ yl)oxy]pyridazine

432 2-[6-(piperidin-4-yloxy)pyridazin-3-yl]-5-(lH-pyrazol-4-yl)p henol

2-{6-[(1 ?,5S)-8-azabicyclo[3.2.1]oct-3-ylamino]pyridazin-3-yl}-5-(lH -pyrazol-4- 433 ¹ yl)phenol

6-[2-methoxy-6-(lH-pyrazol-4-yl)pyridin-3-yl]-N-methyl-N-(2, 2,6,6- 434 ¹ tetramethylpiperidin-4-yl)pyridazin-3-amine Cpd Name

435 3-[4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetramethylpiperid in-4-yl)oxy]pyridazine 436 ¹ 2-{6-[(2,6-dimethylpiperidin-4-yl)oxy]pyridazin-3-yl}-5-(lH- pyrazol-4-yl)phenol

3-[2-fluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetrameth ylpiperidin-4- 437 ¹ yl)oxy]pyridazine

3-[4-(l-methyl-lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-te tramethylpiperidin-4- 438 yl)oxy]pyridazine

439 ¹ 2-[6-(2,7-diazaspiro[3.5]non-2-yl)pyridazin-3-yl]-5-(lH-pyra zol-4-yl)phenol

440 3-fluoro-4-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o]pyridazin-3-yl}phenol

441 2-{6-[(2,6-dimethylpiperidin-4-yl)oxy]pyridazin-3-yl}-5-(lH- pyrazol-l-yl)phenol

N-methyl-6-(2-methyl-2H-indazol-5-yl)-N-(2,2,6,6-tetramethyl piperidin-4-yl)pyridazin-

442 3 -amine

443 2-methyl-5-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyrida zin-3-yl}-2H-indazole

444 3-(4-chloro-2-methoxyphenyl)-6-[(2,2,6,6-tetramethylpiperidi n-4-yl)oxy]pyridazine

N-methyl-6-(2-methylpyrazolo[l,5-a]pyridin-3-yl)-N-(2,2,6 ,6-tetramethylpiperidin-4-

445 yl)pyridazin-3-amine

446 6-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyridazin-3-yl} imidazo[l,2-a]pyridine

3-[2-methoxy-4-(lH-pyrazol-l-yl)phenyl]-6-[(2,2,6,6-tetra methylpiperidin-4-

447 yl)oxy]pyridazine

3-[5-(lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-tetramethyl piperidin-4- 448 ¹ yl)oxy]pyridazine

3-[5-(l-methyl-lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-te tramethylpiperidin-4- 449 yl)oxy]pyridazine

3-[4-(lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-tetramethyl piperidin-4- 450 ¹ yl)oxy]pyridazine

5- (3,5-dimethyl-lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpip eridin-4-

451 yl)oxy]pyridazin-3-yl}phenol

6- [2-fluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6-tet ramethylpiperidin-4-

452 yl)pyridazin-3-amine

453 3-methoxy-4-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyrid azin-3-yl}phenol

3-[2-methoxy-4-(4-nitro-lH-pyrazol-l-yl)phenyl]-6-[(2,2,6,6- tetramethylpiperidin-4-

454 yl)oxy]pyridazine

455 4-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyridazin-3-yl} benzene-l,3-diol

6-[2-chloro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6-t etramethylpiperidin-4- 456 ¹ yl)pyridazin-3-amine

2- (lH-pyrazol-4-yl)-4-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)o xy]pyridazin-3- 457 yl}pyrimidin-5-amine

3- [2,6-difluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetrame thylpiperidin-4- 458 ¹ yl)oxy]pyridazine Cpd Name

459 2-[6-(2,6-diazaspiro[3.4]oct-2-yl)pyridazin-3-yl]-5-(lH-pyra zol-4-yl)phenol

3-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-6-(lH-pyrazol-4- 460 ¹ yl)pyridin-2-ol

6-(lH-pyrazol-4-yl)-3-{6-[(2,2,6,6-tetramethylpiperidin-4-yl )oxy]pyridazin-3- 461 yl}pyridin-2-ol

N,2,2,6,6-pentamethyl-N-{5-[3-(lH-pyrazol-4-yl)phenoxy]-l,3, 4-thiadiazol-2- 462 ¹ yl}piperidin-4-amine

N,2,2,6,6-pentamethyl-N-{5-[4-(lH-pyrazol-4-yl)phenoxy]-l,3, 4-thiadiazol-2- 463 ¹ yl}piperidin-4-amine

3-[2-(diiluoromethyl)-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6 -tetramethylpiperidin-4- 464 ¹ yl)oxy]pyridazine and

6-[2-(difluoromethyl)-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N- (2,2,6,6- 465 ¹ tetramethylpiperidin-4-yl)pyridazin-3-amine wherein a form of the compound is selected from the group consisting of a prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

In one aspect, the compound of Formula (I) or a form thereof includes a compound selected from the group consisting of:

2-{6-[(1 ?,5S)-8-azabicyclo[3.2.1]oct-3-yl(methyl)amino]pyridazin-3-y l}-5-(lH- 411 ¹ pyrazol-4-yl)phenol

2-[6-((1 ?,5S)-8-azabicyclo[3.2.1]oct-3-ylamino)pyridazin-3-yl]-5-(lH -pyrazol-4- 412 ¹ yl)phenol

5-(lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpiperidin-4-yl )amino]pyridazin-3- 413 ¹ yljphenol

5-(l-methyl-lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpiper idin-4-yl)oxy]pyridazin-3- 414 yljphenol

2-[6-((1 ?,5S)-8-azabicyclo[3.2.1]oct-3-yloxy)pyridazin-3-yl]-5-(lH-p yrazol-4- 415 ¹ yl)phenol

5-(5-methyl-lH-pyrazol-4-yl)-2-{6-[methyl(2,2,6,6-tetramethy lpiperidin-4-

416 yl)amino]pyridazin-3-yl}phenol

5-(lH-imidazol-l-yl)-2-{ 6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyridazin-3-

417 yljphenol

5-(5-methyl-lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpiper idin-4-yl)oxy]pyridazin-3-

418 yljphenol

2-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-5-(4-nitro-lH- 419 ¹ pyrazol-l-yl)phenol 6-[2-methoxy-4-(4-nitro-lH-pyrazol-l-yl)phenyl]-N-methyl-N-( 2,2,6,6-

420 tetramethylpiperidin-4-yl)pyridazin-3-amine

5-(4-amino-lH-pyrazol-l-yl)-2-{6-[(2,2,6,6-tetramethylpiperi din-4-yl)oxy]pyridazin-3-

421 yljphenol

2- [6-(l-methyl- 1,2,3, 6-tetrahydropyridin-4-yl)pyridazin-3-yl]-5-(lH-pyrazol-4- 422 ¹ yl)phenol

5- (4-nitro-lH-pyrazol-l-yl)-2-{6-[(2,2,6,6-tetramethylpiperidi n-4-yl)oxy]pyridazin-3- 423 yljphenol

424 ¹ 5-(lH-pyrazol-4-yl)-2-[6-(l,2,3,6-tetrahydropyridin-4-yl)pyr idazin-3-yl]phenol

425 ¹ 2-[6-(l-ethyl-l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl] -5-(lH-pyrazol-4-yl)phenol 426 ¹ 2-{6-[methyl(piperidin-4-yl)amino]pyridazin-3-yl}-5-(lH-pyra zol-4-yl)phenol

427 ¹ 2-[6-(piperidin-4-ylamino)pyridazin-3-yl]-5-(lH-pyrazol-4-yl )phenol

6- [2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6 -tetramethylpiperidin- 428 ¹ 4-yl)pyridazin-3-amine

429 ¹ 2-[6-(8-azabicyclo[3.2.1]oct-2-en-3-yl)pyridazin-3-yl]-5-(lH -pyrazol-4-yl)phenol

6-[2,3-difluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin- 430 ¹ 4-yl)pyridazin-3-amine

3- [2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetrame thylpiperidin-4- 431 ¹ yl)oxy]pyridazine

432 2-[6-(piperidin-4-yloxy)pyridazin-3-yl]-5-(lH-pyrazol-4-yl)p henol

2- {6-[(1 ?,5S)-8-azabicyclo[3.2.1]oct-3-ylamino]pyridazin-3-yl}-5-(lH -pyrazol-4- 433 ¹ yl)phenol

6-[2-methoxy-6-(lH-pyrazol-4-yl)pyridin-3-yl]-N-methyl-N-(2, 2,6,6- 434 ¹ tetramethylpiperidin-4-yl)pyridazin-3-amine

435 3-[4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetramethylpiperid in-4-yl)oxy]pyridazine 436 ¹ 2-{6-[(2,6-dimethylpiperidin-4-yl)oxy]pyridazin-3-yl}-5-(lH- pyrazol-4-yl)phenol

3- [2-fluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetramethyl piperidin-4- 437 ¹ yl)oxy]pyridazine

3-[4-(l-methyl-lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-te tramethylpiperidin-4- 438 yl)oxy]pyridazine

439 ¹ 2-[6-(2,7-diazaspiro[3.5]non-2-yl)pyridazin-3-yl]-5-(lH-pyra zol-4-yl)phenol

440 3-fluoro-4-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o]pyridazin-3-yl}phenol

441 2-{6-[(2,6-dimethylpiperidin-4-yl)oxy]pyridazin-3-yl}-5-(lH- pyrazol-l-yl)phenol

N-methyl-6-(2-methyl-2H-indazol-5-yl)-N-(2,2,6,6-tetramethyl piperidin-4-yl)pyridazin-

442 3 -amine

443 2-methyl-5-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyrida zin-3-yl}-2H-indazole

444 3-(4-chloro-2-methoxyphenyl)-6-[(2,2,6,6-tetramethylpiperidi n-4-yl)oxy]pyridazine

N-methyl-6-(2-methylpyrazolo[l,5-a]pyridin-3-yl)-N-(2,2,6 ,6-tetramethylpiperidin-4-

445 yl)pyridazin-3-amine 446 6-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyridazin-3-yl} imidazo[l,2-a]pyridine

3-[2-methoxy-4-(lH-pyrazol-l-yl)phenyl]-6-[(2,2,6,6-tetra methylpiperidin-4-

447 yl)oxy]pyridazine

3-[5-(lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-tetramethyl piperidin-4- 448 ¹ yl)oxy]pyridazine

3-[5-(l-methyl-lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-te tramethylpiperidin-4- 449 yl)oxy]pyridazine

3-[4-(lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-tetramethyl piperidin-4- 450 ¹ yl)oxy]pyridazine

5- (3,5-dimethyl-lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpip eridin-4-

451 yl)oxy]pyridazin-3-yl}phenol

6- [2-fluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6-tet ramethylpiperidin-4-

452 yl)pyridazin-3-amine

453 3-methoxy-4-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyrid azin-3-yl}phenol

3-[2-methoxy-4-(4-nitro-lH-pyrazol-l-yl)phenyl]-6-[(2,2,6,6- tetramethylpiperidin-4-

454 yl)oxy]pyridazine

455 4-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyridazin-3-yl} benzene-l,3-diol

6-[2-chloro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6-t etramethylpiperidin-4- 456 ¹ yl)pyridazin-3-amine

2- (lH-pyrazol-4-yl)-4-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)o xy]pyridazin-3- 457 yl}pyrimidin-5-amine

3- [2,6-difluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetrame thylpiperidin-4- 458 ¹ yl)oxy]pyridazine

459 2-[6-(2,6-diazaspiro[3.4]oct-2-yl)pyridazin-3-yl]-5-(lH-pyra zol-4-yl)phenol

3-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-6-(lH-pyrazol-4- 460 ¹ yl)pyridin-2-ol

6-(lH-pyrazol-4-yl)-3-{6-[(2,2,6,6-tetramethylpiperidin-4-yl )oxy]pyridazin-3- 461 yl}pyridin-2-ol

N,2,2,6,6-pentamethyl-N-{5-[3-(lH-pyrazol-4-yl)phenoxy]-l,3, 4-thiadiazol-2- 462 ¹ yl}piperidin-4-amine

N,2,2,6,6-pentamethyl-N-{5-[4-(lH-pyrazol-4-yl)phenoxy]-l,3, 4-thiadiazol-2- 463 ¹ yl}piperidin-4-amine

3-[2-(diiluoromethyl)-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6 -tetramethylpiperidin-4- 464 ¹ yl)oxy]pyridazine and

6-[2-(difluoromethyl)-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N- (2,2,6,6- 465 ¹ tetramethylpiperidin-4-yl)pyridazin-3-amine wherein a form of the compound is selected from the group consisting of a prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof. Another embodiment of the use of a compound salt of Formula (I) or a form thereof includes a method of use of a compound salt of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound salt of Formula (I) or a form thereof to the subject, selected from the group consisting of:

Cpd Name

2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-4- 32 (trifluoromethyl)phenol hydrochloride

2- (6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridazin -3-yl)-4-(lH-pyrazol-l- 53 yl)phenol hydrochloride

65 2-(6-piperazin- l-yl-pyridazin-3-yl)-5- lH-pyrazol- 1-yl-phenol hydrochloride

82 3-(6-(piperazin-l-yl)pyridazin-3-yl)naphthalene-2,7-diol trifluoroacetate

86 3-(6-(l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl)naphthal ene-2,7-diol trifluoroacetate

3- (6-(l -methyl- l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl)naphthalene-2, 7-diol

88 trifluoroacetate

89 3-(6-(piperidin-4-yl)pyridazin-3-yl)naphthalene-2,7-diol trifluoroacetate

6-hydroxy-5-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-yl)-2,3- 151 dihydro- lH-inden- 1 -one oxime hydrochloride

2- amino-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)p yridazin-3-yl)-8H-

153 indeno[l,2-d]thiazol-5-ol hydrochloride

9-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5,6-

154 dihydroimidazo[5,l-a]isoquinolin-8-ol hydrochloride

3- fluoro-5-(2-methoxypyridin-4-yl)-2-(6-(methyl(2,2,6,6-tetram ethylpiperidin-4-

160 yl)amino)pyridazin-3-yl)phenol hydrochloride

4- (3-fluoro-5-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidi n-4-yl)amino)pyridazin-3-

161 yl)phenyl)pyridin-2(lH)-one hydrochloride

4- (3-fluoro-5-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidi n-4-yl)amino)pyridazin-3-

162 yl)phenyl)-l-methylpyridin-2(lH)-one hydrochloride

5- (3-fluoro-5-hydroxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidi n-4-yl)amino)pyridazin-3-

163 yl)phenyl)-l-methylpyridin-2(lH)-one hydrochloride

3-fluoro-5-(lH-pyrazol-4-yl)-2-(6-((2,2,6,6-tetramethylpiper idin-4-yl)oxy)pyridazin-3-

164 yl)phenol hydrochloride

5-chloro-3-fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin- 4-yl)amino)pyridazin-3-

165 yl)phenol hydrochloride

3-fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-5-(lH-

166 pyrazol-4-yl)phenol hydrochloride

3-fluoro-2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amin o)pyridazin-3-yl)-5-(l-

167 methyl- 1 H-pyrazol-4-yl)phenol hydrochloride Cpd Name

3- (lH-imidazol-l-yl)-6-(6-(methyl(2,2,6,6-teta

226 yl)quinolin-7-ol hydrochloride

6- (6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridazin -3-yl)quinoline-3,7-diol

227 formate

7- hydroxy-l-methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4 -yl)amino)pyridazin-3- 231 yl)quinolin-2(lH)-one hydrochloride

4- methoxy-7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino )pyridazin-3-yl)quinolin

238 6-ol formate

7-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)quinoxalin-6-ol

239 hydrochloride

2- methyl-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino) pyridazin-3-yl)-4- 254 (tetrahydro-2H-pyran-4-yl)quinolin-7-ol formate

4- (dimethylamino)-6-(6-(methyl(2,2,6,6-tetramethylpiperidin-4- yl)amino)pyridazin-3-yl)- 256 quinolin-7-ol formate

6-hydroxy-2-methyl-7-(6-(methyl(2,2,6,6-tetramethylpiperidin -4-yl)amino)pyridazin-3- 281 yl)isoquinolin-l(2H)-one hydrochloride

3- (5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-l,3,4-th iadiazol-2-yl)naphthalen- 322 2-ol hydrobromide

N-methyl-5-(5-(l-methyl-lH-pyrazol-4-yl)pyridin-2-yl)-N-(2,2 ,6,6-tetramethylpiperidin- 342 4-yl)-l,3,4-thiadiazol-2-amine hydrochloride

3-fluoro-2-(5-((3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(lH) -yl)-l,3,4-thiadiazol-2-yl)- 396 5-(lH-pyrazol-4-yl)phenol dihydrochloride

2-(2-chloro-4-(lH-pyrazol-4-yl)phenyl)-5-((3aR,6aS)-hexahydr opyrrolo[3,4-c]pyrrol-

405 2(lH)-yl)-l,3,4-thiadiazole hydrochloride

2-(2-chloro-4-(lH-pyrazol-4-yl)phenyl)-5-(2,7-diazaspiro[4.5 ]decan-2-yl)-l,3,4-

406 thiadiazole hydrochloride

(R)-(4-(5-(2-chloro-4-(lH-pyrazol-4-yl)phenyl)-l,3,4-thiadia zol-2-yl)piperazin-2-

407 yl)methanol hydrochloride

2-{6-[8-azabicyclo[3.2.1]oct-3-yl(methyl)amino]pyridazin-3-y l}-5-(lH-pyrazol-4-

411 yl)phenol hydrochloride

2-[6-(8-azabicyclo[3.2.1]oct-3-ylamino)pyridazin-3-yl]-5-(lH -pyrazol-4-yl)phenol

412 hydrochloride

5- (lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)a mino]pyridazin-3-

413 yl} phenol hydrochloride

2-[6-(8-azabicyclo[3.2.1]oct-3-yloxy)pyridazin-3-yl]-5-(lH-p yrazol-4-yl)phenol

415 hydrochloride

2-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-5-(4-nitro-lH- 419 pyrazol- 1 -yl)phenol dihydrochloride Cpd Name

2-[6-(l-methyl-l,2,3,6-tetra ydropyridin-4-yl)pyridazin-3-yl]-5-(lH-pyrazol-4-yl)phenol 422 trihydrochloride

5- (lH-pyrazol-4-yl)-2-[6-(l,2,3,6-tetrahydropyridin-4-yl)pyrid azin-3-yl]phenol

424 trihydrochloride

2-[6-(l-ethyl-l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl] -5-(lH-pyrazol-4-yl)phenol

425 trihydrochloride

2-{6-[methyl(piperidin-4-yl)amino]pyridazin-3-yl}-5-(lH-pyra zol-4-yl)phenol

426 tetrahydrochloride

427 2-[6-(piperidin-4-ylamino)pyridazin-3-yl]-5-(lH-pyrazol-4-yl )phenol tetrahydrochloride

6- [2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6 -tetramethylpiperidin-4-

428 yl)pyridazin-3-amine tetrahydrochloride

2- [6-(8-azabicyclo[3.2.1 ]oct-2-en-3 -yl)pyridazin-3 -yl] -5-( 1 H-pyrazol-4-yl)phenol

429 hydrochloride

6-[2,3-difluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin-4-

430 yl)pyridazin-3-amine hydrochloride

3- [2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetrame thylpiperidin-4-

431 yl)oxy]pyridazine trihydrochloride

2-{6-[(lR,5S)-8-azabicyclo[3.2.1]oct-3-ylamino]pyridazin-3-y l}-5-(lH-pyrazol-4-

433 yl)phenol hydrochloride

6-[2-methoxy-6-(lH-pyrazol-4-yl)pyridin-3-yl]-N-methyl-N-(2, 2,6,6-

434 tetramethylpiperidin-4-yl)pyridazin-3-amine hydrochloride

2- {6-[(2,6-dimethylpiperidin-4-yl)oxy]pyridazin-3-yl}-5-(lH-py razol-4-yl)phenol

436 trihydrochloride

3- [2-fluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetramethyl piperidin-4-

437 yl)oxy]pyridazine hydrochloride

2- [6-(2,7-diazaspiro[3.5]non-2-yl)pyridazin-3-yl]-5-(lH-pyrazo l-4-yl)phenol

439 tetrahydrochloride

3- [5-(lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-tetramethylpi peridin-4- 448 yl)oxy]pyridazine hydrochloride

3-[4-(lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-tetramethyl piperidin-4- 450 yl)oxy]pyridazine hydrochloride

6-[2-chloro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6-t etramethylpiperidin-4- 456 yl)pyridazin-3-amine trihydrochloride

3-[2,6-difluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetra methylpiperidin-4- 458 yl)oxy]pyridazine trihydrochloride

3-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-6-(lH-pyrazol-4- 460 yl)pyridin-2-ol hydrochloride

N,2,2,6,6-pentamethyl-N-{5-[3-(lH-pyrazol-4-yl)phenoxy]-l,3, 4-thiadiazol-2- 462 yl}piperidin-4-amine hydrochloride Cpd Name

N,2,2,6,6-pentamethyl-N- { 5- [4-( lH-pyrazol-4-yl)phenoxy] - 1 ,3 ,4-thiadiazol-2-

463 yl}piperidin-4-amine hydrochloride

3-[2-(difluoromethyl)-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6 -tetramethylpiperidin-4-

464 yl)oxy]pyridazine hydrochloride and

6-[2-(difluoromethyl)-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N- (2,2,6,6-

465 tetramethylpiperidin-4-yl)pyridazin-3-amine hydrochloride wherein a form of the compound salt is selected from the group consisting of a prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

In one aspect, the compound salt of Formula (I) or a form thereof includes a compound salt selected from the group consisting of:

2-{6-[8-azabicyclo[3.2.1]oct-3-yl(methyl)amino]pyridazin-3-y l}-5-(lH-pyrazol-4-

411 yl)phenol hydrochloride

2-[6-(8-azabicyclo[3.2.1]oct-3-ylamino)pyridazin-3-yl]-5-(lH -pyrazol-4-yl)phenol

412 hydrochloride

5-(lH-pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpiperidin-4-yl )amino]pyridazin-3-

413 yl} phenol hydrochloride

2-[6-(8-azabicyclo[3.2.1]oct-3-yloxy)pyridazin-3-yl]-5-(lH-p yrazol-4-yl)phenol

415 hydrochloride

2-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-5-(4-nitro-lH- 419 pyrazol- 1 -yl)phenol dihydrochloride

2-[6-(l-methyl-l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl ]-5-(lH-pyrazol-4-yl)phenol 422 trihydrochloride

5- (lH-pyrazol-4-yl)-2-[6-(l,2,3,6-tetrahydropyridin-4-yl)pyrid azin-3-yl]phenol

424 trihydrochloride

2-[6-(l-ethyl-l,2,3,6-tetrahydropyridin-4-yl)pyridazin-3-yl] -5-(lH-pyrazol-4-yl)phenol

425 trihydrochloride

2-{6-[methyl(piperidin-4-yl)amino]pyridazin-3-yl}-5-(lH-pyra zol-4-yl)phenol

426 tetrahydrochloride

427 2-[6-(piperidin-4-ylamino)pyridazin-3-yl]-5-(lH-pyrazol-4-yl )phenol tetrahydrochloride

6- [2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6 -tetramethylpiperidin-4-

428 yl)pyridazin-3-amine tetrahydrochloride

2- [6-(8-azabicyclo[3.2.1 ]oct-2-en-3 -yl)pyridazin-3 -yl] -5-( 1 H-pyrazol-4-yl)phenol

429 hydrochloride

6-[2,3-difluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin-4-

430 yl)pyridazin-3-amine hydrochloride 3-[2,5-difluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetra methylpiperidin-4- 431 yl)oxy]pyridazine trihydrochloride

2-{6-[(lR,5S)-8-azabicyclo[3.2.1]oct-3-ylamino]pyridazin-3-y l}-5-(lH-pyrazol-4-

433 yl)phenol hydrochloride

6-[2-methoxy-6-(lH-pyrazol-4-yl)pyridin-3-yl]-N-methyl-N-(2, 2,6,6-

434 tetramethylpiperidin-4-yl)pyridazin-3-amine hydrochloride

2- {6-[(2,6-dimethylpiperidin-4-yl)oxy]pyridazin-3-yl}-5-(lH-py razol-4-yl)phenol

436 trihydrochloride

3- [2-fluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetramethyl piperidin-4-

437 yl)oxy]pyridazine hydrochloride

2- [6-(2,7-diazaspiro[3.5]non-2-yl)pyridazin-3-yl]-5-(lH-pyrazo l-4-yl)phenol

439 tetrahydrochloride

3- [5-(lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-tetramethylpi peridin-4- 448 yl)oxy]pyridazine hydrochloride

3-[4-(lH-pyrazol-4-yl)thiophen-2-yl]-6-[(2,2,6,6-tetramethyl piperidin-4- 450 yl)oxy]pyridazine hydrochloride

6-[2-chloro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6,6-t etramethylpiperidin-4- 456 yl)pyridazin-3-amine trihydrochloride

3-[2,6-difluoro-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6-tetra methylpiperidin-4- 458 yl)oxy]pyridazine trihydrochloride

3-{6-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-6-(lH-pyrazol-4- 460 yl)pyridin-2-ol hydrochloride

N,2,2,6,6-pentamethyl-N-{5-[3-(lH-pyrazol-4-yl)phenoxy]-l,3, 4-thiadiazol-2-

462 yl}piperidin-4-amine hydrochloride

N,2,2,6,6-pentamethyl-N- { 5- [4-( lH-pyrazol-4-yl)phenoxy] - 1 ,3 ,4-thiadiazol-2-

463 yl}piperidin-4-amine hydrochloride

3-[2-(difluoromethyl)-4-(lH-pyrazol-4-yl)phenyl]-6-[(2,2,6,6 -tetramethylpiperidin-4-

464 yl)oxy]pyridazine hydrochloride and

6-[2-(difluoromethyl)-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N- (2,2,6,6-

465 tetramethylpiperidin-4-yl)pyridazin-3-amine hydrochloride wherein a form of the compound salt is selected from the group consisting of a prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

Another embodiment of the present description includes a method of use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof to the subject. Another embodiment of the present description includes a method of use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound salt of Formula (I) or a form thereof to the subject.

Another embodiment of the present description includes a use of the compound of

Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof to the subject.

Another embodiment of the present description includes a use of the compound salt of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound salt of Formula (I) or a form thereof to the subject.

Chemical Definitions

As used herein, the term "Ci- ₄ alkyl" generally refers to saturated hydrocarbon radicals having from one to four carbon atoms in a straight or branched chain configuration, including, without limitation, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and the like. In some embodiments, Ci- ₄ alkyl includes Ci_ ₃ alkyl, Ci_ ₂ alkyl, and the like. A Ci- ₄ alkyl radical may be optionally substituted where allowed by available valences.

As used herein, the term "C ₂ - ₆ alkenyl" generally refers to partially unsaturated hydrocarbon radicals having from two to five carbon atoms in a straight or branched chain configuration and one or more carbon-carbon double bonds therein, including, without limitation, ethenyl, allyl, propenyl and the like. In some embodiments, C ₂ - ₆ alkenyl includes C ₂ - ₄ alkenyl, C ₂ - ₃ alkenyl, and the like. A C ₂ - ₆ alkenyl radical may be optionally substituted where allowed by available valences.

As used herein, the term "Ci- ₄ alkoxy" generally refers to saturated hydrocarbon radicals having from one to four carbon atoms in a straight or branched chain configuration of the formula: -0-Ci_ ₄ alkyl, including, without limitation, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, and the like. In some embodiments, Ci_ ₄ alkoxy includes Ci_ ₃ alkoxy, Ci_ ₂ alkoxy and the like. A Ci- ₄ alkoxy radical may be optionally substituted where allowed by available valences. As used herein, the term "C ₃ _i ₄ cycloalkyl" generally refers to a saturated monocyclic, bicyclic or polycyclic hydrocarbon radical, including, without limitation, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, lH-indanyl, indenyl,

tetrahydro-naphthalenyl and the like. In some embodiments, C ₃ _i ₄ cycloalkyl includes

C ₃ _iocycloalkyl, C ₃ _ ₈ cycloalkyl, C ₃ _ ₇ cycloalkyl, Cs-scycloalkyl, C9_iocycloalkyl and the like. A C ₃ _i ₄ cycloalkyl radical may be optionally substituted where allowed by available valences.

As used herein, the term "C ₃ _i ₄ cycloalkenyl" generally refers to a partially unsaturated monocyclic, bicyclic or polycyclic hydrocarbon radical having one or more chemically stable carbon-carbon double bonds therein, including, without limitation, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl and the like. In some embodiments, C ₃ _i ₄ cycloalkenyl includes C ₃ _ ₇ cycloalkenyl, C ₃ _ ₈ cycloalkenyl, C5_ ₈ cycloalkenyl,

C ₃ _iocycloalkenyl and the like. A C ₃ _i ₄ cycloalkenyl radical may be optionally substituted where allowed by available valences.

As used herein, the term "aryl" generally refers to a monocyclic, bicyclic or polycyclic aromatic carbon atom ring structure radical, including, without limitation, phenyl, naphthyl, anthracenyl, fluorenyl, azulenyl, phenanthrenyl and the like. An aryl radical may be optionally substituted where allowed by available valences.

As used herein, the term "heteroaryl" generally refers to a monocyclic, bicyclic or polycyclic aromatic carbon atom ring structure radical in which one or more carbon atom ring members have been replaced, where allowed by structural stability, with one or more

heteroatoms, such as an O, S or N atom, including, without limitation, furanyl, thienyl (also referred to as thiophenyl), pyrrolyl, pyrazolyl, imidazolyl, isoxazolyl, isothiazolyl, oxazolyl, thiazolyl, triazolyl, oxadiazolyl, thiadiazolyl, tetrazolyl, pyranyl, thiopyranyl, pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, indolyl, indazolyl, indolizinyl, benzofuranyl, benzothienyl, benzimidazolyl, benzothiazolyl, benzooxazolyl, 9H-purinyl, quinoxalinyl, isoindolyl, quinolinyl, isoquinolinyl, quinazolinyl, acridinyl, phthalazinyl, imidazo[l,2- a]pyridinyl, imidazo[ 1 ,5-a]pyridinyl, imidazo[5, l-a]isoquinolinyl, 1 ,4-dihydroindeno[ 1 ,2-c]- 1H- pyrazolyl, 2,3-dihydro-lH-inden-l-one, 2,3-dihydro-lH-indenyl, 3,4-dihydroquinolin-2(lH)- one, 5 ,6-dihydroimidazo [5 , 1 -a] isoquinolinyl, 8H-indeno [ 1 ,2-d] thiazolyl,

benzo[c][l,2,5]oxadiazolyl, benzo[d]oxazol-2(3H)-one, quinolin-2(lH)-one, quinazolin-4(lH)- one, quinazoline-2,4(lH,3H)-dione, benzo-[d] oxazolyl, pyrazolo[l,5-a]pyridinyl, and the like. A heteroaryl radical may be optionally substituted on a carbon or nitrogen atom ring member where allowed by available valences.

As used herein, the term "heterocyclyl" generally refers to a saturated or partially unsaturated monocyclic, bicyclic or polycyclic carbon atom ring structure radical in which one or more carbon atom ring members have been replaced, where allowed by structural stability, with a heteroatom, such as an O, S or N atom, including, without limitation, oxiranyl, oxetanyl, azetidinyl, dihydrofuranyl, tetrahydrofuranyl, dihydrothienyl, tetrahydrothienyl, pyrrolinyl, pyrrolidinyl, dihydropyrazolyl, pyrazolinyl, pyrazolidinyl, dihydroimidazolyl, imidazolinyl, imidazolidinyl, isoxazolinyl, isoxazolidinyl, isothiazolinyl, isothiazolidinyl, oxazolinyl, oxazolidinyl, thiazolinyl, thiazolidinyl, triazolinyl, triazolidinyl, oxadiazolinyl, oxadiazolidinyl, thiadiazolinyl, thiadiazolidinyl, tetrazolinyl, tetrazolidinyl, dihydro-2H-pyranyl,

dihydro-pyridinyl, tetrahydro-pyridinyl, 1,2,3,6-tetrahydropyridinyl, hexahydro-pyridinyl, dihydro-pyrimidinyl, tetrahydro-pyrimidinyl, 1,4,5,6-tetrahydropyrimidinyl, dihydro-pyrazinyl, tetrahydro-pyrazinyl, dihydro-pyridazinyl, tetrahydro-pyridazinyl, piperazinyl, piperidinyl, morpholinyl, thiomorpholinyl, dihydro-triazinyl, tetrahydro-triazinyl, hexahydro-triazinyl, 1,4-diazepanyl, dihydro-indolyl, indolinyl, tetrahydro-indolyl, dihydro-indazolyl,

tetrahydro-indazolyl, dihydro-isoindolyl, dihydro-benzofuranyl, tetrahydro-benzofuranyl, dihydro-benzothienyl, tetrahydro-benzothienyl, dihydro-benzimidazolyl,

tetrahydro-benzimidazolyl, dihydro-benzooxazolyl, 2,3-dihydrobenzo[d]oxazolyl,

tetrahydro-benzooxazolyl, dihydro-benzooxazinyl, 3,4-dihydro-2H-benzo[b][l,4]oxazinyl, tetrahydro-benzooxazinyl, benzo[l,3]dioxolyl, benzo[l,4]dioxanyl, dihydro-purinyl,

tetrahydro-purinyl, dihydro-quinolinyl, tetrahydro-quinolinyl, 1,2,3,4-tetrahydroquinolinyl, dihydro-isoquinolinyl, 3,4-dihydroisoquinolin-(lH)-yl, tetrahydro-isoquinolinyl, 1,2,3,4- tetrahydroisoquinolinyl, dihydro-quinazolinyl, tetrahydro-quinazolinyl, dihydro-quinoxalinyl, tetrahydro-quinoxalinyl, 1,2,3,4-tetrahydroquinoxalinyl, 1,3-dioxolanyl, 2,5-dihydro-lH- pyrrolyl, 4,5-dihydro-lH-imidazolyl, tetrahydro-2H-pyranyl, hexahydropyrrolo[3,4- b][l,4]oxazin-(2H)-yl, (4aR,7aS)-hexahydropyrrolo[3,4-b][l,4]oxazin-(4aH)-yl, 3,4-dihydro-2H- pyrido[3,2-b][l,4]oxazinyl, (cis)-octahydrocyclopenta[c]pyrrolyl, hexahydropyrrolo[3,4- b]pyrrol-(lH)-yl, (3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-(lH)-yl, (3aR,6aS)- hexahydropyrrolo[3,4-c]pyrrol-(lH)-yl, 5H-pyrrolo[3,4-b]pyridin-(7H)-yl, 5,7-dihydro-6H- pyrrolo[3,4-b]pyridinyl, tetrahydro-lH-pyrrolo[3,4-b]pyridin-(2H,7H,7aH)-yl, hexahydro-lH- pyrrolo[3,4-b]pyridin-(2H)-yl, (4aR,7aR)-hexahydro-lH-pyrrolo[3,4-b]pyridin-(2H)-yl, octahydro-6H-pyrrolo[3,4-b]pyridinyl, 2,3,4, 9-tetrahydro-lH-carbazolyl, 1,2,3,4- tetrahydropyrazino[ 1 ,2-a]indolyl, 2,3-dihydro- lH-pyrrolo[ 1 ,2-a]indolyl, (3aR,6aR)- hexahydrocyclopenta[c]pyrrol-(lH)-yl, (3aR,4R,6aS)-hexahydrocyclopenta[c]pyrrol-(lH)-yl, (3aR,4S,6aS)-hexahydrocyclopenta[c]pyrrol-(lH)-yl, (3aR,5r,6aS)- hexahydrocyclopenta[c]pyrrol-(lH)-yl, l,3-dihydro-2H-isoindolyl, octahydro-2H-isoindolyl, (3aS)-l,3,3a,4,5,6-hexahydro-2H-isoindolyl, (3aR,4R,7aS)-lH-isoindol- (3H,3aH,4H,5H,6H,7H,7aH)-yl, (3aR,7aS)-octahydro-2H-isoindolyl, (3aR,4R,7aS)-octahydro- 2H-isoindolyl, (3aR,4S,7aS)-octahydro-2H-isoindolyl, 2,5-diazabicyclo[2.2.1]heptanyl, 2- azabicyclo[2.2.1]heptenyl, 3-azabicyclo[3.1.0]hexanyl, 3,6-diazabicyclo[3.1.0]hexanyl, (1R,5S)- 3-azabicyclo[3.1.0]hexanyl, (lS,5R)-3-azabicyclo[3.2.0]heptanyl, 5-azaspiro[2.4]heptanyl, 2,6- diazaspiro[3.3]heptanyl, 2,5-diazaspiro[3.4]octanyl, 2,6-diazaspiro[3.4]octanyl, 2,7- diazaspiro[3.5]nonanyl, 2,7-diazaspiro[4.4]nonanyl, 2-azaspiro[4.5]decanyl, 2,8- diazaspiro [4.5] decanyl, 3 ,6-diazabicyclo [3.2.1] octyl, 1 ,4-dihydroindeno [ 1 ,2-c]pyrazolyl, dihydropyranyl, dihydropyridinyl, dihydroquinolinyl, 8H-indeno[l,2-d]thiazolyl,

tetrahydroimidazo[l,2-a]pyridinyl, pyridin-2(lH)-one, (lR,5S)-8-azabicyclo[3.2.1]octyl, 8-azabicyclo[3.2.1]oct-2-enyl and the like. A heterocyclyl radical may be optionally substituted on a carbon or nitrogen atom ring member where allowed by available valences.

As used herein, the term "C2- ₄ alkenyl-amino-carbonyl" refers to a radical of the formula: -C(=0)-NH-C ₂ - ₄ alkenyl.

As used herein, the term "Ci- ₄ alkoxy-Ci- ₄ alkoxy" refers to a radical of the

formula: - O-C i _ ₄ alkyl- O-C i _ ₄ alkyl .

As used herein, the term "Ci_ ₄ alkoxy-carbonyl" refers to a radical of the

formula: -C(=0)-0-Ci_ ₄ alkyl.

As used herein, the term "Ci_ ₄ alkoxy-carbonyl-amino" refers to a radical of the formula: -NH-C(=0)-0-Ci_ ₄ alkyl.

As used herein, the term "Ci_ ₄ alkoxy-carbonyl-amino-Ci_ ₄ alkoxy" refers to a radical of the formula: -0-Ci_ ₄ alkyl-NH-C(=0)-0-Ci_ ₄ alkyl.

As used herein, the term "Ci- ₄ alkyl-Ci_ ₄ alkoxy" refers to a radical of the

formula: -0-Ci_ ₄ alkyl-Ci_ ₄ alkyl. As used herein, the term "Ci- ₄ alkyl-amino" refers to a radical of the

formula: -NH-C _1-4 alkyl.

As used herein, the term "(Ci_ ₄ alkyl) ₂ -amino" refers to a radical of the

formula: -N(Ci_ ₄ alkyl) ₂ .

As used herein, the term "Ci- ₄ alkyl-amino-Ci- ₄ alkoxy" refers to a radical of the formula: -0-Ci- ₄ alkyl-NH-Ci- ₄ alkyl.

As used herein, the term "(Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkoxy" refers to a radical of the formula: -0-Ci_ ₄ alkyl-N(Ci_ ₄ alkyl) ₂ .

As used herein, the term "Ci- ₄ alkyl-amino-Ci- ₄ alkyl" refers to a radical of the

formula: -C _1- alkyl-NH-C _1- alkyl.

As used herein, the term "(Ci_ ₄ alkyl) ₂ -amino-Ci_ ₄ alkyl" refers to a radical of the formula: -Ci_ ₄ alkyl-N(Ci_ ₄ alkyl) ₂ .

As used herein, the term "Ci- ₄ alkyl-amino-carbonyl" refers to a radical of the

formula: -C(=0)-NH-Ci_ ₄ alkyl.

As used herein, the term "(Ci_ ₄ alkyl) ₂ -amino-carbonyl" refers to a radical of the formula:

-C(=0)-N(Ci_ ₄ alkyl) ₂ .

As used herein, the term "Ci- ₄ alkyl-amino-carbonyl-Ci- ₄ alkyl" refers to a radical of the formula: -Ci- ₄ alkyl-C(=0)-NH-Ci- ₄ alkyl.

As used herein, the term "(Ci_ ₄ alkyl) ₂ -amino-carbonyl-Ci_ ₄ alkyl" refers to a radical of the formula: -Ci_ ₄ alkyl-C(=0)-N(Ci_ ₄ alkyl) ₂ .

As used herein, the term "Ci- ₄ alkyl-carbonyl" refers to a radical of the

formula: -C(=0)-Ci_ ₄ alkyl.

As used herein, the term "Ci_ ₄ alkyl-carbonyl-amino" refers to a radical of the

formula: -NH-C(=0)-Ci_ ₄ alkyl.

As used herein, the term "Ci- ₄ alkyl-carbonyl-amino-Ci- ₄ alkoxy" refers to a radical of the formula: -0-Ci- ₄ alkyl-NH-C(=0)-Ci- ₄ alkyl.

As used herein, the term "Ci_ ₄ alkyl-carbonyl-amino-Ci_ ₄ alkyl" refers to a radical of the formula: -Ci_ ₄ alkyl-NH-C(=0)-Ci_ ₄ alkyl.

As used herein, the term "amino" refers to a radical of the formula: -NH ₂ .

As used herein, the term "amino-Ci- ₄ alkoxy" refers to a radical of the

formula: -0-Ci_ ₄ alkyl-NH ₂ . As used herein, the term "amino-Ci- ₄ alkyl" refers to a radical of the

formula: -Ci_4alkyl-NH ₂ .

As used herein, the term "amino-carbonyl" refers to a radical of the

formula: -C(=0)-NH ₂ .

As used herein, the term "cyano" refers to a radical of the formula: -CN.

As used herein, the term "C ₃ _ ₇ cycloalkyl-Ci_ ₄ alkoxy" refers to a radical of the formula: -0-Ci_ ₄ alkyl-C ₃ _ ₇ cycloalkyl.

As used herein, the term "halo-Ci_ ₄ alkoxy" refers to a radical of the

formula: -0-Ci- ₄ alkyl-halo, wherein Ci- ₄ alkyl may be partially or completely substituted where allowed by available valences with one or more halogen atoms. In some embodiments, halo-Ci_ ₄ alkoxy includes halo-Ci_ ₆ alkoxy, halo-Ci_ ₄ alkoxy and the like.

As used herein, the term "halo-Ci_ ₄ alkyl" refers to a radical of the

formula: -Ci- ₄ alkyl-halo, wherein Ci- ₄ alkyl may be partially or completely substituted where allowed by available valences with one or more halogen atoms. In some embodiments, halo-Ci_ ₄ alkyl includes halo-Ci_ ₆ alkyl, halo-Ci_ ₄ alkyl and the like.

As used herein, the term "heteroaryl-Ci_ ₄ alkyl" refers to a radical of the

formula: -Ci- ₄ alkyl-heteroaryl.

As used herein, the term "heteroaryl-Ci- ₄ alkyl-amino" refers to a radical of the formula: -NH-C i_ ₄ alkyl-heteroaryl.

As used herein, the term "heteroaryl-Ci_ ₄ alkyl-amino-carbonyl" refers to a radical of the formula: -C(=0)-NH-Ci_ ₄ alkyl-heteroaryl.

As used herein, the term "heteroaryl-Ci- ₄ alkyl-amino-carbonyl-Ci- ₄ alkyl" refers to a radical of the formula: -Ci_ ₄ alkyl-C(=0)-NH-Ci_ ₄ alkyl-heteroaryl.

As used herein, the term "heteroaryl-Ci_ ₄ alkyl-carbonyl-amino" refers to a radical of the formula: -NH-C(=0)-C _1- alkyl-heteroaryl.

As used herein, the term "heteroaryl-Ci- ₄ alkyl-carbonyl-amino-Ci- ₄ alkyl" refers to a radical of the formula: -Ci_ ₄ alkyl-NH-C(=0)-Ci_ ₄ alkyl-heteroaryl.

As used herein, the term "heterocyclyl-Ci_ ₄ alkoxy" refers to a radical of the

formula: -Ci- ₄ alkoxy-heterocyclyl.

As used herein, the term "heterocyclyl-Ci- ₄ alkyl" refers to a radical of the

formula: -Ci_ ₄ alkyl-heterocyclyl. As used herein, the term "hydroxyl" refers to a radical of the formula: -OH.

As used herein, the term "hydroxyl-Ci- ₄ alkoxy" refers to a radical of the

formula: -0-Ci_ ₄ alkyl-OH, wherein Ci_ ₄ alkyl may be partially or completely substituted where allowed by available valences with one or more hydroxy radicals.

As used herein, the term "hydroxyl-Ci- ₄ alkyl" refers to a radical of the

formula: -Ci- ₄ alkyl-OH, wherein Ci- ₄ alkyl may be partially or completely substituted where allowed by available valences with one or more hydroxy radicals.

As used herein, the term "hydroxyl-Ci_ ₄ alkyl-amino" refers to a radical of the

formula: -NH-Ci- ₄ alkyl-OH, wherein Ci- ₄ alkyl may be partially or completely substituted where allowed by available valences with one or more hydroxyl radicals.

As used herein, the term "hydroxyl-imino" refers to the =NOH radical of the formula: C(=NOH).

As used herein, the term "oxo" refers to the radical of the formula: C=0.

As used herein, the term "phenyl-Ci- ₄ alkoxy" refers to a radical of the

formula: -Ci_ ₄ alkoxy-phenyl.

As used herein, the term "substituent" means positional variables on the atoms of a core molecule that are substituted at a designated atom position, replacing one or more hydrogens on the designated atom, provided that the designated atom' s normal valency is not exceeded, and that the substitution results in a stable compound. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds. A person of ordinary skill in the art should note that any carbon as well as heteroatom with valences that appear to be unsatisfied as described or shown herein is assumed to have a sufficient number of hydrogen atom(s) to satisfy the valences described or shown. In certain instances one or more substituents having a double bond (e.g., "oxo" or "=0") as the point of attachment may be described, shown or listed herein within a substituent group, wherein the structure may only show a single bond as the point of attachment to the core structure of Formula (I). A person of ordinary skill in the art would understand that, while only a single bond is shown, a double bond is intended for those substituents.

As used herein, the term "and the like," with reference to the definitions of chemical terms provided herein, means that variations in chemical structures that could be expected by one skilled in the art include, without limitation, isomers (including chain, branching or positional structural isomers), hydration of ring systems (including saturation or partial unsaturation of monocyclic, bicyclic or polycyclic ring structures) and all other variations where allowed by available valences which result in a stable compound.

For the purposes of this description, where one or more substituent variables for a compound of Formula (I) or a form thereof encompass functionalities incorporated into a compound of Formula (I), each functionality appearing at any location within the disclosed compound may be independently selected, and as appropriate, independently and/or optionally substituted.

As used herein, the terms "independently selected," or "each selected" refer to functional variables in a substituent list that may occur more than once on the structure of Formula (I), the pattern of substitution at each occurrence is independent of the pattern at any other occurrence.

Further, the use of a generic substituent variable on any formula or structure for a compound described herein is understood to include the replacement of the generic substituent with species substituents that are included within the particular genus, e.g. , aryl may be replaced with phenyl or naphthalenyl and the like, and that the resulting compound is to be included within the scope of the compounds described herein.

As used herein, the terms "each instance of or "in each instance, when present," when used preceding a phrase such as "...C ₃ _i ₄ cycloalkyl, C ₃ -i ₄ cycloalkyl-Ci- ₄ alkyl, aryl,

aryl-Ci_ ₄ alkyl, heteroaryl, heteroaryl-Ci_ ₄ alkyl, heterocyclyl and heterocyclyl-Ci_ ₄ alkyl," are intended to refer to the C ₃ _i ₄ cycloalkyl, aryl, heteroaryl and heterocyclyl ring systems when each are present either alone or as a substituent.

As used herein, the term "optionally substituted" means optional substitution with the specified substituent variables, groups, radicals or moieties.

Compound Forms

As used herein, the term "form" means a compound of Formula (I) having a form selected from the group consisting of a free acid, free base, prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

In certain embodiments described herein, the form of the compound of Formula (I) is a free acid, free base or salt thereof. In certain embodiments described herein, the form of the compound of Formula (I) is a salt thereof.

In certain embodiments described herein, the form of the compound of Formula (I) is an isotopologue thereof.

In certain embodiments described herein, the form of the compound of Formula (I) is a stereoisomer, racemate, enantiomer or diastereomer thereof.

In certain embodiments described herein, the form of the compound of Formula (I) is a tautomer thereof.

In certain embodiments described herein, the form of the compound of Formula (I) is a pharmaceutically acceptable form.

In certain embodiments described herein, the compound of Formula (I) or a form thereof is isolated for use.

As used herein, the term "isolated" means the physical state of a compound of Formula (I) or a form thereof after being isolated and/or purified from a synthetic process (e.g., from a reaction mixture) or natural source or combination thereof according to an isolation or purification process or processes described herein or which are well known to the skilled artisan (e.g., chromatography, recrystallization and the like) in sufficient purity to be characterized by standard analytical techniques described herein or well known to the skilled artisan.

As used herein, the term "protected" means that a functional group in a compound of Formula (I) or a form thereof is in a form modified to preclude undesired side reactions at the protected site when the compound is subjected to a reaction. Suitable protecting groups will be recognized by those with ordinary skill in the art as well as by reference to standard textbooks such as, for example, T.W. Greene et al, Protective Groups in organic Synthesis (1991), Wiley, New York. Such functional groups include hydroxy, phenol, amino and carboxylic acid.

Suitable protecting groups for hydroxy or phenol include trialkylsilyl or diarylalkylsilyl (e.g., t-butyldimethylsilyl, t-butyldiphenylsilyl or trimethylsilyl), tetrahydropyranyl, benzyl, substituted benzyl, methyl, methoxymethanol, and the like. Suitable protecting groups for amino, amidino and guanidino include t-butoxycarbonyl, benzyloxycarbonyl, and the like. Suitable protecting groups for carboxylic acid include alkyl, aryl or arylalkyl esters. In certain instances, the protecting group may also be a polymer resin, such as a Wang resin or a 2-chlorotrityl- chloride resin. Protecting groups may be added or removed in accordance with standard techniques, which are well-known to those skilled in the art and as described herein. It will also be appreciated by those skilled in the art, although such protected derivatives of compounds described herein may not possess pharmacological activity as such, they may be administered to a subject and thereafter metabolized in the body to form compounds described herein which are pharmacologically active. Such derivatives may therefore be described as "prodrugs". All prodrugs of compounds described herein are included within the scope of the use described herein.

As used herein, the term "prodrug" means a form of an instant compound (e.g. , a drug precursor) that is transformed in vivo to yield an active compound of Formula (I) or a form thereof. The transformation may occur by various mechanisms (e.g. , by metabolic and/or non-metabolic chemical processes), such as, for example, by hydrolysis and/or metabolism in blood, liver and/or other organs and tissues. A discussion of the use of prodrugs is provided by T. Higuchi and W. Stella, "Pro-drugs as Novel Delivery Systems," Vol. 14 of the A.C.S.

Symposium Series, and in Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987.

In one example, when a compound of Formula (I) or a form thereof contains a carboxylic acid functional group, a prodrug can comprise an ester formed by the replacement of the hydrogen atom of the acid group with a functional group such as alkyl and the like. In another example, when a compound of Formula (I) or a form thereof contains a hydroxyl functional group, a prodrug form can be prepared by replacing the hydrogen atom of the hydroxyl with another functional group such as alkyl, alkylcarbonyl or a phosphonate ester and the like. In another example, when a compound of Formula (I) or a form thereof contains an amine functional group, a prodrug form can be prepared by replacing one or more amine hydrogen atoms with a functional group such as alkyl or substituted carbonyl. Pharmaceutically acceptable prodrugs of compounds of Formula (I) or a form thereof include those compounds substituted with one or more of the following groups: carboxylic acid esters, sulfonate esters, amino acid esters, phosphonate esters and mono-, di- or triphosphate esters or alkyl substituents, where appropriate. As described herein, it is understood by a person of ordinary skill in the art that one or more of such substituents may be used to provide a compound of Formula (I) or a form thereof as a prodrug. One or more compounds described herein may exist in unsolvated as well as solvated forms with pharmaceutically acceptable solvents such as water, ethanol, and the like, and the description herein is intended to embrace both solvated and unsolvated forms.

As used herein, the term "solvate" means a physical association of a compound described herein with one or more solvent molecules. This physical association involves varying degrees of ionic and covalent bonding, including hydrogen bonding. In certain instances the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. As used herein, "solvate" encompasses both solution- phase and isolatable solvates. Non-limiting examples of suitable solvates include ethanolates, methanolates, and the like.

As used herein, the term "hydrate" means a solvate wherein the solvent molecule is water.

The compounds of Formula (I) can form salts, which are intended to be included within the scope of this description. Reference to a compound of Formula (I) or a form thereof herein is understood to include reference to salt forms thereof, unless otherwise indicated. The term

"salt(s)", as employed herein, denotes acidic salts formed with inorganic and/or organic acids, as well as basic salts formed with inorganic and/or organic bases. In addition, when a compound of Formula (I) or a form thereof contains both a basic moiety, such as, without limitation an amine moiety, and an acidic moiety, such as, but not limited to a carboxylic acid, zwitterions ("inner salts") may be formed and are included within the term "salt(s)" as used herein.

The term "pharmaceutically acceptable salt(s)", as used herein, means those salts of compounds described herein that are safe and effective (i.e., non-toxic, physiologically acceptable) for use in mammals and that possess biological activity, although other salts are also useful. Salts of the compounds of the Formula (I) may be formed, for example, by reacting a compound of Formula (I) or a form thereof with an amount of acid or base, such as an equivalent amount, in a medium such as one in which the salt precipitates or in an aqueous medium followed by lyophilization.

Pharmaceutically acceptable salts include one or more salts of acidic or basic groups present in compounds described herein. Embodiments of acid addition salts include, and are not limited to, acetate, ascorbate, benzoate, benzenesulfonate, bisulfate, bitartrate, borate, bromide, butyrate, chloride, citrate, camphorate, camphorsulfonate, ethanesulfonate, formate, fumarate, gentisinate, gluconate, glucaronate, glutamate, iodide, isonicotinate, lactate, maleate, methanesulfonate, naphthalenesulfonate, nitrate, oxalate, pamoate, pantothenate, phosphate, propionate, saccharate, salicylate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate (also known as tosylate), trifluoroacetate salts and the like. Certain embodiments of acid addition salts include chloride, dichloride, trichloride, bromide, acetate, formate or trifluoroacetate salts.

Additionally, acids which are generally considered suitable for the formation of pharmaceutically useful salts from basic pharmaceutical compounds are discussed, for example, by P. Stahl et al, Camille G. (eds.) Handbook of Pharmaceutical Salts. Properties, Selection and Use. (2002) Zurich: Wiley- VCH; S. Berge et al, Journal of Pharmaceutical Sciences (1977) 66(1) 1-19; P. Gould, International J. of Pharmaceutics (1986) 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.

Suitable basic salts include, but are not limited to, aluminum, ammonium, calcium, lithium, magnesium, potassium, sodium and zinc salts.

All such acid salts and base salts are intended to be included within the scope of pharmaceutically acceptable salts as described herein. In addition, all such acid and base salts are considered equivalent to the free forms of the corresponding compounds for purposes of this description.

Compounds of Formula (I) and forms thereof, may further exist in a tautomeric form. All such tautomeric forms are contemplated and intended to be included within the scope of the compounds of Formula (I) or a form thereof as described herein.

The compounds of Formula (I) or a form thereof may contain asymmetric or chiral centers, and, therefore, exist in different stereoisomeric forms. The present description is intended to include all stereoisomeric forms of the compounds of Formula (I) as well as mixtures thereof, including racemic mixtures.

The compounds described herein may include one or more chiral centers, and as such may exist as racemic mixtures (R/S) or as substantially pure enantiomers and diastereomers. The compounds may also exist as substantially pure (R) or (S) enantiomers (when one chiral center is present). In one embodiment, the compounds described herein are (S) isomers and may exist as enantiomerically pure compositions substantially comprising only the (S) isomer. In another embodiment, the compounds described herein are (R) isomers and may exist as enantiomerically pure compositions substantially comprising only the (R) isomer. As one of skill in the art will recognize, when more than one chiral center is present, the compounds described herein may also exist as a (R,R), (R,S), (S,R) or (S,S) isomer, as defined by IUPAC Nomenclature

Recommendations.

As used herein, the term "substantially pure" refers to compounds consisting substantially of a single isomer in an amount greater than or equal to 90%, in an amount greater than or equal to 92%, in an amount greater than or equal to 95%, in an amount greater than or equal to 98%, in an amount greater than or equal to 99%, or in an amount equal to 100% of the single isomer.

In one aspect of the description, a compound of Formula (I) or a form thereof is a substantially pure (S) enantiomer form present in an amount greater than or equal to 90%, in an amount greater than or equal to 92%, in an amount greater than or equal to 95%, in an amount greater than or equal to 98%, in an amount greater than or equal to 99%, or in an amount equal to 100%.

In one aspect of the description, a compound of Formula (I) or a form thereof is a substantially pure (R) enantiomer form present in an amount greater than or equal to 90%, in an amount greater than or equal to 92%, in an amount greater than or equal to 95%, in an amount greater than or equal to 98%, in an amount greater than or equal to 99%, or in an amount equal to 100%.

As used herein, a "racemate" is any mixture of isometric forms that are not

"enantiomerically pure", including mixtures such as, without limitation, in a ratio of about 50/50, about 60/40, about 70/30, or about 80/20.

In addition, the present description embraces all geometric and positional isomers. For example, if a compound of Formula (I) or a form thereof incorporates a double bond or a fused ring, both the cis- and trans-forms, as well as mixtures, are embraced within the scope of the description. Diastereomeric mixtures can be separated into their individual diastereomers on the basis of their physical chemical differences by methods well known to those skilled in the art, such as, for example, by chromatography and/or fractional crystallization. Enantiomers can be separated by use of chiral HPLC column or other chromatographic methods known to those skilled in the art. Enantiomers can also be separated by converting the enantiomeric mixture into a diastereomeric mixture by reaction with an appropriate optically active compound (e.g. , chiral auxiliary such as a chiral alcohol or Mosher's acid chloride), separating the diastereomers and converting (e.g. , hydrolyzing) the individual diastereomers to the corresponding pure

enantiomers. Also, some of the compounds of Formula (I) may be atropisomers (e.g., substituted biaryls) and are considered as part of this description.

All stereoisomers (for example, geometric isomers, optical isomers and the like) of the present compounds (including those of the salts, solvates, esters and prodrugs of the compounds as well as the salts, solvates and esters of the prodrugs), such as those which may exist due to asymmetric carbons on various substituents, including enantiomeric forms (which may exist even in the absence of asymmetric carbons), rotameric forms, atropisomers, and diastereomeric forms, are contemplated within the scope of this description, as are positional isomers (such as, for example, 4-pyridyl and 3-pyridyl). Individual stereoisomers of the compounds described herein may, for example, be substantially free of other isomers, or may be present in a racemic mixture, as described supra.

The use of the terms "salt", "solvate", "ester", "prodrug" and the like, is intended to equally apply to the salt, solvate, ester and prodrug of enantiomers, stereoisomers, rotamers, tautomers, positional isomers, racemates or isotopologues of the instant compounds.

The term "isotopologue" refers to isotopically-enriched compounds described herein which are identical to those recited herein, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds described herein include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, fluorine and chlorine, such as ² H, ³ H, ¹³ C, ¹⁴ C, ¹⁵ N, ¹⁸ 0, ¹⁷ 0, ³¹ P, ³² P, ³⁵ S, ¹⁸ F, ³⁵ C1 and ³⁶ C1, respectively, each of which are also within the scope of this description.

Certain isotopically-enriched compounds described herein (e.g., those labeled with H

14 3 and C) are useful in compound and/or substrate tissue distribution assays. Tritiated (i.e., H) and carbon- 14 (i.e. , ¹⁴ C) isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium (i.e., H) may afford certain therapeutic advantages resulting from greater metabolic stability (e.g. , increased in vivo half-life or reduced dosage requirements) and hence may be preferred in some circumstances. Polymorphic crystalline and amorphous forms of the compounds of Formula (I) and of the salts, solvates, hydrates, esters and prodrugs of the compounds of Formula (I) are further intended to be included in the present description.

Compound Uses The present description relates to a method of use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising

administering an effective amount of the compound or a form thereof to the subject.

The present description further relates to use of the compound of Formula (I)or a form thereof for treating or ameliorating HD in a subject in need thereof.

The present description further relates to use of the compound of Formula (I) or a form thereof having activity toward HD.

The present description further relates to use of the compound of Formula (I) or a form thereof in a combination therapy to provide additive or synergistic activity, thus enabling the development of a combination product for treating or ameliorating HD.

In addition to monotherapeutic use, the instant compounds are useful in a combination therapy with current standard of agents, having additive or synergistic activity with one or more known agents.

A combination therapy comprising compounds described herein in combination with one or more known drugs may be used to treat HD regardless of whether HD is responsive to the known drug.

Embodiments of the present description include the use of a compound of Formula (I)or a form thereof in a combination therapy for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof and an effective amount of one or more agent(s).

Embodiments of the present description include the use of a compound of Formula (I) or a form thereof in a combination therapy for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof and an effective amount of one or more agent(s).

In an embodiment of a use or method provided herein, compounds of Formula (I) or a form thereof used in combination with one or more additional agents can be administered to a subject or contacted with a subject or patient cell(s) prior to, concurrently with, or subsequent to administering to the subject or patient or contacting the cell with an additional agent(s). A compound(s) of Formula (I) or a form thereof and an additional agent(s) can be administered to a subject or contacted with a cell in single composition or different compositions. In a specific embodiments, a compound(s) of Formula (I) or a form thereof is used in combination with gene therapy to inhibit HTT expression (using, e.g. , viral delivery vectors) or the administration of another small molecule HTT inhibitor. In another specific embodiment, a compound(s) of Formula (I) or a form thereof are used in combination with cell replacement using differentiated non-mutant HTT stem cells. In another specific embodiment, a compound(s) of Formula (I) or a form thereof are used in combination with cell replacement using differentiated HTT stem cells.

In one embodiment, provided herein is the use of compounds of Formula (I) or a form thereof in combination with supportive standard of care therapies, including palliative care.

An embodiment of the present description includes the use of a compound of Formula (I) or a form thereof in the preparation of a kit comprising the compound of Formula (I) or a form thereof and instructions for administering an effective amount of the compound of Formula (I) or a form thereof and an effective amount of one or more agent(s) in a combination therapy for treating or ameliorating HD in a subject in need thereof.

Accordingly, the present description relates to use of a compound of Formula (I) or a form thereof for treating or ameliorating HD. In accordance with the use of the present description, compounds that are useful in selectively treating or ameliorating HD, have been identified and use of these compounds for treating or ameliorating HD has been provided.

One embodiment of the use of the present description relates to use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof to the subject.

One embodiment of the use of the present description relates to a method of use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound to the subject.

An embodiment of the use of the present description relates to a method of use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound to the subject. An embodiment of the use of the present description relates to use of a compound of Formula (I) or a form thereof in the manufacture of a medicament for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the

medicament to the subject.

An embodiment of the use of the present description relates to use of a compound of

Formula (I) or a form thereof in the preparation of a kit comprising the compound of Formula (I) or a form thereof and instructions for administering the compound for treating or ameliorating HD in a subject in need thereof.

In one respect, for each of such embodiments, the subject is treatment naive. In another respect, for each of such embodiments, the subject is not treatment naive.

As used herein, the term "treating" refers to: (i) preventing a disease, disorder or condition from occurring in a subject that may be predisposed to the disease, disorder and/or condition but has not yet been diagnosed as having the disease, disorder and/or condition;

(ii) inhibiting a disease, disorder or condition, i.e., arresting the development thereof; and/or (iii) relieving a disease, disorder or condition, i.e., causing regression of the disease, disorder and/or condition.

As used herein, the term "subject" refers to an animal or any living organism having sensation and the power of voluntary movement, and which requires oxygen and organic food. Nonlimiting examples include members of the human, primate, equine, porcine, bovine, murine, rattus, canine and feline specie. In some embodiments, the subject is a mammal or a warmblooded vertebrate animal. In other embodiments, the subject is a human. As used herein, the term "patient" may be used interchangeably with "subject" and "human".

As used herein, the terms "effective amount" or "therapeutically effective amount" mean an amount of compound of Formula (I) or a form, composition or medicament thereof effective in inhibiting the above-noted diseases and thus producing the desired therapeutic, ameliorative, inhibitory or preventative effect in a subject in need thereof.

The dose administered to achieve an effective target plasma concentration may also be administered based upon the weight of the subject or patient. Doses administered on a weight basis may be in the range of about 0.001 mg/kg/day to about 3500 mg/kg/day, or about 0.001 mg/kg/day to about 3000 mg/kg/day, or about 0.001 mg/kg/day to about 2500 mg/kg/day, or about 0.001 mg/kg/day to about 2000 mg/kg/day, or about 0.001 mg/kg/day to about 1500 mg/kg/day, or about 0.001 mg/kg/day to about 1000 mg/kg/day, or about 0.001 mg/kg/day to about 500 mg/kg/day, or about 0.001 mg/kg/day to about 250 mg/kg/day, or about 0.001 mg/kg/day to about 100 mg/kg/day, or about 0.001 mg/kg/day to about 75 mg/kg/day, or about 0.001 mg/kg/day to about 50 mg/kg/day, or about 0.001 mg/kg/day to about 40 mg/kg/day, or about 0.001 mg/kg/day to about 30 mg/kg/day, or about 0.001 mg/kg/day to about 20 mg/kg/day, or about 0.001 mg/kg/day to about 10 mg/kg/day, or about 0.01 mg/kg/day to about 2000 mg/kg/day, or about 0.01 mg/kg/day to about 1500 mg/kg/day, or about 0.01 mg/kg/day to about 1000 mg/kg/day, or about 0.01 mg/kg/day to about 600 mg/kg/day, or about 0.01 mg/kg/day to about 500 mg/kg/day, or about 0.01 mg/kg/day to about 300 mg/kg/day, or about 0.015 mg/kg/day to about 200 mg/kg/day, or about 0.02 mg/kg/day to about 100 mg/kg/day, or about 0.025 mg/kg/day to about 100 mg/kg/day, or about 0.03 mg/kg/day to about 100 mg/kg/day, wherein said amount is orally administered once (once in approximately a 24 hour period), twice (once in approximately a 12 hour period) or thrice (once in approximately an 8 hour period) daily according to subject weight.

In certain embodiments, the effective amount will be in a range of from about 0.001 mg/kg/day to about 500 mg/kg/day, or about 0.01 mg/kg/day to about 500 mg/kg/day, or about 0.1 mg to about 500 mg/kg/day, or about 1.0 mg/day to about 500 mg/kg/day, in single, divided, or a continuous dose for a patient or subject having a weight in a range of between about 40 to about 200 kg (which dose may be adjusted for patients or subjects above or below this range, particularly children under 40 kg). The typical adult subject is expected to have a median weight in a range of about 70 kg.

In another embodiment, where daily doses are adjusted based upon the weight of the subject or patient, compounds described herein may be formulated for delivery at about 0.02, 0.025, 0.03, 0.05, 0.06, 0.075, 0.08, 0.09, 0.10, 0.20, 0.25, 0.30, 0.50, 0.60, 0.75, 0.80, 0.90, 1.0, 1.10, 1.20, 1.25, 1.50, 1.75, 2.0, 3.0, 5.0, 10, 20, 30, 40, 50, 100, 150, 200, 250, 300, 400 or 500 mg/kg/day. Daily doses adjusted based upon the weight of the subject or patient may be administered as a single, divided, or continuous dose. In embodiments where a dose of compound is given more than once per day, the dose may be administered twice, thrice, or more times per day.

Within the scope of the present description, the "effective amount" of a compound of

Formula (I) or a form thereof for use in the manufacture of a medicament, for use in the preparation of a pharmaceutical kit or in a method of use for treating or ameliorating HD in a subject in need thereof is intended to include an amount in a range of from about 0.001 mg/kg/day to about 3500 mg/kg/day, or about 0.001 mg/kg/day to about 3000 mg/kg/day, or about 0.001 mg/kg/day to about 2500 mg/kg/day, or about 0.001 mg/kg/day to about 2000 mg/kg/day, or about 0.001 mg/kg/day to about 1500 mg/kg/day, or about 0.001 mg/kg/day to about 1000 mg/kg/day, or about 0.001 mg/kg/day to about 500 mg/kg/day, or about 0.001 mg/kg/day to about 250 mg/kg/day, or about 0.001 mg/kg/day to about 100 mg/kg/day, or about 0.001 mg/kg/day to about 75 mg/kg/day, or about 0.001 mg/kg/day to about 50 mg/kg/day, or about 0.001 mg/kg/day to about 40 mg/kg/day, or about 0.001 mg/kg/day to about 30 mg/kg/day, or about 0.001 mg/kg/day to about 20 mg/kg/day, or about 0.001 mg/kg/day to about 10 mg/kg/day, or about 0.01 mg/kg/day to about 2000 mg/kg/day, or about 0.01 mg/kg/day to about 1500 mg/kg/day, or about 0.01 mg/kg/day to about 1000 mg/kg/day, or about 0.01 mg/kg/day to about 600 mg/kg/day, or about 0.01 mg/kg/day to about 500 mg/kg/day, or about 0.01 mg/kg/day to about 300 mg/kg/day, or about 0.015 mg/kg/day to about 200 mg/kg/day, or about 0.02 mg/kg/day to about 100 mg/kg/day, or about 0.025 mg/kg/day to about 100 mg/kg/day, or about 0.03 mg/kg/day to about 100 mg/kg/day, wherein said amount is administered once (once in approximately a 24 hour period; i.e., "q.d."), twice (once in approximately a 12 hour period; i.e., "b.i.d." or "q.l2h"), thrice (once in approximately an 8 hour period; i.e., "t.i.d." or "q.8h"), or four times (once in approximately a 6 hour period; i.e., "q.d.s.", "q.i.d." or "q.6h") daily according to subject weight.

Such amounts may further include an amount in a range of from about 0.001 mg to about 3500 mg administered daily; 0.001 mg to about 3000 mg administered daily; 0.001 mg to about 2500 mg administered daily; 0.001 mg to about 2000 mg administered daily; 0.001 mg to about 1500 mg administered daily; 0.001 mg to about 1000 mg administered daily; 0.001 mg to about 500 mg administered daily; 0.001 mg to about 250 mg administered daily; 1.0 mg to about 3500 mg administered daily; 1.0 mg to about 1500 mg administered daily; 1.0 mg to about 1000 mg administered daily; 10.0 mg to about 600 mg administered daily; 0.5 mg to about 2000 mg administered daily; or, an amount in a range of from about 5.0 mg to about 300 mg administered daily.

For example, the effective amount may be the amount required to treat HD in a subject or, more specifically, in a human. The effective amount for a subject will depend upon various factors, including the subject' s body weight, size and health. Effective amounts for a given patient can be determined by routine experimentation that is within the skill and judgment of the clinician.

For any compound, the effective amount can be estimated initially either in cell culture assays or in relevant animal models, such as a mouse, chimpanzee, marmoset or tamarin animal model. Relevant animal models may also be used to determine the appropriate concentration range and route of administration. Such information can then be used to determine useful doses and routes for administration in humans. Therapeutic efficacy and toxicity may be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g. , ED ₅₀ (the dose therapeutically effective in 50% of the population) and LD ₅₀ (the dose lethal to 50% of the population). The dose ratio between therapeutic and toxic effects is therapeutic index, and can be expressed as the ratio, LD ₅₀ /ED ₅₀ . In some embodiments, the effective amount is such that a large therapeutic index is achieved. In further embodiments, the dosage is within a range of circulating concentrations that include an ED ₅₀ with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed, sensitivity of the patient, and the route of administration.

More specifically, the concentration-biological effect relationships observed with regard to a compound of Formula (I) or a form thereof indicate a target plasma concentration ranging from approximately 0.001 μg/mL to approximately 50 μg/mL, from approximately 0.01 μg/mL to approximately 20 μg/mL, from approximately 0.05 μg/mL to approximately 10 μg/mL, or from approximately 0.1 μg/mL to approximately 5 μg/mL. To achieve such plasma

concentrations, the compounds described herein may be administered at doses that vary, such as, for example, without limitation, from 0.1 ng to 10,000 mg, depending upon the route of administration in single, divided, or continuous doses for a patient weighing between about 10 to about 100 kg (which dose may be adjusted for patients within this weight range, particularly for children under 40 kg).

The exact dosage will be determined by the practitioner, in light of factors related to the subject. Dosage and administration may be adjusted to provide sufficient levels of the active agent(s) or to maintain the desired effect. Factors which may be taken into account include the severity of the disease state, general health of the subject, ethnicity, age, weight, gender, diet, time of day and frequency of administration, drug combination(s), reaction sensitivities, experience with other therapies, and tolerance/response to therapy. Long-acting pharmaceutical compositions may be administered every 2, 3 or 4 days, once every week, or once every two weeks depending on half-life and clearance rate of the particular formulation.

The compounds and compositions described herein may be administered to the subject via any drug delivery route known in the art. Nonlimiting examples include oral, ocular, rectal, buccal, topical, nasal, sublingual, transdermal, subcutaneous, intramuscular, intraveneous (bolus and infusion), intracerebral, and pulmonary routes of administration.

In one aspect, provided herein are methods for modulating the amount of HTT

(huntingtin protein), comprising contacting a human cell with a compound of Formula (I) or a form thereof. In a specific embodiment, provided herein are methods for modulating the amount of HTT, comprising contacting a human cell with a compound of Formula (I) or a form thereof that modulates the expression of HTT. The human cell can be contacted with a compound of Formula (I) or a form thereof in vitro, or in vivo, e.g., in a non-human animal or in a human. In a specific embodiment, the human cell is from or in a human. In another specific embodiment, the human cell is from or in a human with HD. In another specific embodiment, the human cell is from or in a human with HD, caused by a CAG repeat in the Htt gene, resulting in a loss of HTT expression and/or function. In another embodiment, the human cell is from a human with HD. In another embodiment, the human cell is in a human with HD. In one embodiment, the compound is a form of the compound of Formula (I).

In a specific embodiment, provided herein is a method for enhancing the inhibition of mutant HTT transcribed from the Htt gene, comprising contacting a human cell with a compound of Formula (I) or a form thereof. The human cell can be contacted with a compound of Formula (I) or a form thereof in vitro, or in vivo, e.g., in a non-human animal or in a human. In a specific embodiment, the human cell is from or in a human. In another specific embodiment, the human cell is from or in a human with HD. In another specific embodiment, the human cell is from or in a human with HD, caused by a CAG repeat in the Htt gene, resulting in a loss of wild-type "normal" HTT expression and/or function. In another embodiment, the human cell is from a human with HD. In another embodiment, the human cell is in a human with HD. In one embodiment, the compound is a form of the compound of Formula (I).

In another aspect, provided herein is a method for modulating the inhibition of mutant

HTT transcribed from the Htt gene, comprising administering to a non-human animal model for HD a compound of Formula (I) or a form thereof. In a specific embodiment, provided herein is a method for modulating the inhibition of mutant HTT transcribed from the Htt gene, comprising administering to a non-human animal model for HD a compound of Formula (I) or a form thereof. In a specific embodiment, the compound is a form of the compound of Formula (I).

In another aspect, provided herein is a method for decreasing the amount of mutant HTT, comprising contacting a human cell with a compound of Formula (I) or a form thereof. In a specific embodiment, provided herein is a method for decreasing the amount of mutant HTT, comprising contacting a human cell with a compound of Formula (I) that inhibits the

transcription of mutant HTT (huntingtin mRNA) from the Htt gene. In another specific embodiment, provided herein is a method for decreasing the amount of HTT, comprising contacting a human cell with a compound of Formula (I) that inhibits the expression of mutant HTT transcribed from the Htt gene. The human cell can be contacted with a compound of Formula (I) or a form thereof in vitro, or in vivo, e.g., in a non-human animal or in a human. In a specific embodiment, the human cell is from or in a human. In another specific embodiment, the human cell is from or in a human with HD. In another specific embodiment, the human cell is from or in a human with HD, caused by a CAG repeat in the Htt gene, resulting in a loss of HTT expression and/or function. In another embodiment, the human cell is from a human with HD. In another embodiment, the human cell is in a human with HD. In one embodiment, the compound is a form of the compound of Formula (I).

In certain embodiments, treating or ameliorating HD with a compound of Formula (I) or a form thereof (alone or in combination with an additional agent) has a therapeutic effect and/or beneficial effect. In a specific embodiment, treating HD with a compound of Formula (I) or a form thereof (alone or in combination with an additional agent) results in one, two or more of the following effects: (i) reduces or ameliorates the severity of HD; (ii) delays onset of HD; (iii) inhibits the progression of HD; (iv) reduces hospitalization of a subject; (v) reduces

hospitalization length for a subject; (vi) increases the survival of a subject; (vii) improves the quality of life for a subject; (viii) reduces the number of symptoms associated with HD; (ix) reduces or ameliorates the severity of a symptom(s) associated with HD; (x) reduces the duration of a symptom associated with HD; (xi) prevents the recurrence of a symptom associated with HD; (xii) inhibits the development or onset of a symptom of HD; and/or (xiii) inhibits of the progression of a symptom associated with HD. Metabolites of the Compounds

Also included within the scope of the present description are the use of in vivo metabolic products of the compounds described herein. Such products may result, for example, from the oxidation, reduction, hydrolysis, amidation, esterification and the like of the administered compound, primarily due to enzymatic processes. Accordingly, the description includes the use of compounds produced by a process comprising contacting a compound described herein with a mammalian tissue or a mammal for a period of time sufficient to yield a metabolic product thereof.

Such products typically are identified by preparing a radio-labeled isotopologue (e.g., ¹⁴ C or H) of a compound described herein, administering the radio-labeled compound in a detectable dose (e.g., greater than about 0.5 mg/kg) to a mammal such as a rat, mouse, guinea pig, dog, monkey or human, allowing sufficient time for metabolism to occur (typically about 30 seconds to about 30 hours), and identifying the metabolic conversion products from urine, bile, blood or other biological samples. The conversion products are easily isolated since they are "radiolabeled" by virtue of being isotopically-enriched (others are isolated by the use of antibodies capable of binding epitopes surviving in the metabolite). The metabolite structures are determined in conventional fashion, e.g., by MS or NMR analysis. In general, analysis of metabolites may be done in the same way as conventional drug metabolism studies well-known to those skilled in the art. The conversion products, so long as they are not otherwise found in vivo, are useful in diagnostic assays for therapeutic dosing of the compounds described herein even if they possess no biological activity of their own.

Pharmaceutical Compositions

Embodiments of the present description include the use of a compound of Formula (I) or a form thereof in a pharmaceutical composition for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof in admixture with one or more pharmaceutically acceptable excipient(s).

An embodiment of the present description includes the use of a pharmaceutical composition of the compound of Formula (I) or a form thereof in the preparation of a kit comprising the pharmaceutical composition of the compound of Formula (I) or a form thereof and instructions for administering the compound for treating or ameliorating HD in a subject in need thereof.

As used herein, the term "composition" means a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in the specified amounts.

The pharmaceutical composition may be formulated to achieve a physiologically compatible pH, ranging from about pH 3 to about pH 11. In some embodiments, the

pharmaceutical composition is formulated to achieve a pH of from about pH 3 to about pH 7. In other embodiments, the pharmaceutical composition is formulated to achieve a pH of from about pH 5 to about pH 8.

The term "pharmaceutically acceptable excipient" refers to an excipient for

administration of a pharmaceutical agent, such as the compounds described herein. The term refers to any pharmaceutical excipient that may be administered without undue toxicity.

Pharmaceutically acceptable excipients may be determined in part by the particular composition being administered, as well as by the particular mode of administration and/or dosage form. Nonlimiting examples of pharmaceutically acceptable excipients include carriers, solvents, stabilizers, adjuvants, diluents, etc. Accordingly, there exists a wide variety of suitable formulations of pharmaceutical compositions for the instant compounds described herein (see, e.g. , Remington's Pharmaceutical Sciences).

Suitable excipients may be carrier molecules that include large, slowly metabolized macromolecules such as proteins, polysaccharides, polylactic acids, polyglycolic acids, polymeric amino acids, amino acid copolymers, and inactive antibodies. Other exemplary excipients include antioxidants such as ascorbic acid; chelating agents such as EDTA;

carbohydrates such as dextrin, hydroxyalkylcellulose, hydroxyalkylmethylcellulose (e.g. , hydroxypropylmethylcellulose, also known as HPMC), stearic acid; liquids such as oils, water, saline, glycerol and ethanol; wetting or emulsifying agents; pH buffering substances; and the like. Liposomes are also included within the definition of pharmaceutically acceptable excipients.

The pharmaceutical compositions described herein may be formulated in any form suitable for the intended use described herein. Suitable formulations for oral administration include solids, liquid solutions, emulsions and suspensions, while suitable inhalable formulations for pulmonary administration include liquids and powders. Alternative formulations include syrups, creams, ointments, tablets, and lyophilized solids which can be reconstituted with a physiologically compatible solvent prior to administration.

When intended for oral use for example, tablets, troches, lozenges, aqueous or oil suspensions, non-aqueous solutions, dispersible powders or granules (including micronized particles or nanoparticles), emulsions, hard or soft capsules, syrups or elixirs may be prepared. Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions, and such compositions may contain one or more agents including sweetening agents, flavoring agents, coloring agents, and preserving agents, in order to provide a palatable preparation.

Pharmaceutically acceptable excipients suitable for use in conjunction with tablets include, for example, inert diluents, such as celluloses, calcium or sodium carbonate, lactose, calcium or sodium phosphate; disintegrating agents, such as croscarmellose sodium, cross-linked povidone, maize starch, or alginic acid; binding agents, such as povidone, starch, gelatin or acacia; and lubricating agents, such as magnesium stearate, stearic acid, or talc. Tablets may be uncoated or may be coated by known techniques including microencapsulation to delay disintegration and adsorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate alone or with a wax may be employed.

Formulations for oral use may be also presented as hard gelatin capsules where the active ingredient is mixed with an inert solid diluent, for example celluloses, lactose, calcium phosphate, or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with nonaqueous or oil medium, such as glycerin, propylene glycol, polyethylene glycol, peanut oil, liquid paraffin, or olive oil.

In other embodiments, pharmaceutical compositions described herein may be formulated as suspensions comprising a compound of Formula (I) or a form thereof in admixture with one or more pharmaceutically acceptable excipient(s) suitable for the manufacture of a suspension. In yet other embodiments, pharmaceutical compositions described herein may be formulated as dispersible powders and granules suitable for preparation of a suspension by the addition of one or more excipient(s). Excipients suitable for use in connection with suspensions include suspending agents, such as sodium carboxymethylcellulose, methylcellulose, hydroxypropyl methylcelluose, sodium alginate, polyvinylpyrrolidone, gum tragacanth, gum acacia, dispersing or wetting agents such as a naturally occurring phosphatide (e.g. , lecithin), a condensation product of an alkylene oxide with a fatty acid (e.g. , polyoxyethylene stearate), a condensation product of ethylene oxide with a long chain aliphatic alcohol (e.g. , heptadecaethyleneoxycethanol), a condensation product of ethylene oxide with a partial ester derived from a fatty acid and a hexitol anhydride (e.g. , polyoxyethylene sorbitan monooleate); and thickening agents, such as carbomer, beeswax, hard paraffin, or cetyl alcohol. The suspensions may also contain one or more preservatives such as acetic acid, methyl and/or n-propyl p-hydroxy-benzoate; one or more coloring agents; one or more flavoring agents; and one or more sweetening agents such as sucrose or saccharin.

The pharmaceutical compositions described herein may also be in the form of oil-in- water emulsions. The oily phase may be a vegetable oil, such as olive oil or arachis oil, a mineral oil, such as liquid paraffin, or a mixture of these. Suitable emulsifying agents include naturally-occurring gums, such as gum acacia and gum tragacanth; naturally occurring phosphatides, such as soybean lecithin, esters or partial esters derived from fatty acids; hexitol anhydrides, such as sorbitan monooleate; and condensation products of these partial esters with ethylene oxide, such as polyoxyethylene sorbitan monooleate. The emulsion may also contain sweetening and flavoring agents. Syrups and elixirs may be formulated with sweetening agents, such as glycerol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative, a flavoring or a coloring agent.

Additionally, the pharmaceutical compositions described herein may be in the form of a sterile injectable preparation, such as a sterile injectable aqueous emulsion or oleaginous suspension. Such emulsion or suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, such as a solution in 1,2-propanediol. The sterile injectable preparation may also be prepared as a lyophilized powder. Among the acceptable vehicles and solvents that may be employed are water, Ringer' s solution and isotonic sodium chloride solution. In addition, sterile fixed oils may be employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or di-glycerides. In addition, fatty acids such as oleic acid may likewise be used in the preparation of injectables.

The compounds described herein may be substantially insoluble in water and sparingly soluble in most pharmaceutically acceptable protic solvents and vegetable oils, but generally soluble in medium-chain fatty acids (e.g. , caprylic and capric acids) or triglycerides and in propylene glycol esters of medium-chain fatty acids. Thus, contemplated in the description are compounds which have been modified by substitutions or additions of chemical or biochemical moieties which make them more suitable for delivery (e.g. , increase solubility, bioactivity, palatability, decrease adverse reactions, etc.), for example by esterification, glycosylation, PEGylation, etc.

In some embodiments, the compound described herein is formulated for oral

administration in a lipid-based composition suitable for low solubility compounds. Lipid-based formulations can generally enhance the oral bioavailability of such compounds. As such, pharmaceutical compositions described herein may comprise a effective amount of a compound of Formula (I) or a form thereof, together with at least one pharmaceutically acceptable excipient selected from medium chain fatty acids or propylene glycol esters thereof (e.g. , propylene glycol esters of edible fatty acids such as caprylic and capric fatty acids) and pharmaceutically acceptable surfactants, such as polysorbate 20 or 80 (also referred to as Tween® 20 or Tween® 80, respectively) or polyoxyl 40 hydrogenated castor oil.

In other embodiments, the bioavailability of low solubility compounds may be enhanced using particle size optimization techniques including the preparation of nanoparticles or nanosuspensions using techniques known to those skilled in the art. The compound forms present in such preparations include amorphous, partially amorphous, partially crystalline or crystalline forms.

In alternative embodiments, the pharmaceutical composition may further comprise one or more aqueous solubility enhancer(s), such as a cyclodextrin. Nonlimiting examples of cyclodextrin include hydroxypropyl, hydroxyethyl, glucosyl, maltosyl and maltotriosyl derivatives of α-, β-, and γ-cyclodextrin, and hydroxypropyl-P-cyclodextrin (HPBC). In some embodiments, the pharmaceutical composition further comprises HPBC in a range of from about 0.1% to about 20%, from about 1% to about 15%, or from about 2.5% to about 10%. The amount of solubility enhancer employed may depend on the amount of the compound in the composition.

Preparation of Compounds

Compounds provided herein can be prepared by those skilled in the art, such as, by the synthetic methods set forth in International Application Publication Number WO2014/028459 Al, published February 20, 2014, International Application Publication Number

WO2014/116845 Al, published July 31, 2014, and International Application Publication Number WO2015/017589 Al, published February 5, 2015, each of which are herein

incorporated by reference.

General Schemes

The following reaction schemes illustrate methods to make compounds described herein. It is understood that one skilled in the art would be able to make these compounds by similar methods or by methods known to one skilled in the art.

In general, starting components and reagents may be commercially obtained from various sources such as commercial vendors, synthesized according to methodology known to those skilled in the art, or prepared as described herein. It is understood that in the following description, combinations of substituents and/or variables of the depicted formulae are permissible only if such contributions result in stable compounds.

In general, compounds of Formula (I) described herein can be synthesized following the general procedure for Scheme 1.

Scheme 1

General Procedure for Scheme 1

The starting materials for the above reaction scheme are commercially available or can prepared according to methods known to one skilled in the art or by methods disclosed herein. In general, the compounds described herein are prepared in the above reaction Scheme 1 as follows: a halogenated Compound la (wherein Hal is a halogen selected from bromine or chlorine) is reacted with a Compound lb (wherein H is a reactive hydrogen atom in an amine or alcohol X functional group, wherein X and B for a compound of Formula (I) are as described herein) using a displacement or a metal-mediated cross coupling reaction, such as a Buchwald reaction, to provide an intermediate Compound lc. Compound lc is carried forward and reacted with a boronate acid or boronate ester Compound Id (where B represents a boron atom, R represents a an acid or ester functional group or, when taken together with boron, form a ring system and A for a compound of Formula (I) is as described herein) using a transition metal- mediated cross coupling reaction, such as a Suzuki reaction, to provide a Compound of Formula (I). In a complementary manner, compounds of Formula (I) may also be synthesized in reverse order wherein the boronate Compound Id is reacted first with Compound la followed by reaction of the intermediate with amine Compound lb. Other variations representing different combinations for substituting either or both boronate Compound Id and amine Compound lb on Compound la are intended to be included within the scope of the synthetic methodologies described herein. Specific Examples

To assist in understanding the present description, the following specific examples are included. The experiments relating to this description should not, of course, be construed as specifically limiting the description and such variations of the description, now known or later developed, which would be within the purview of one skilled in the art are considered to fall within the scope of the description as described herein and hereinafter claimed.

Other than in the working examples, unless indicated to the contrary, all numbers expressing quantities of materials, reagents, reaction conditions, experimental data, and so forth used in the specification and claims are to be understood as being modified by the term "about". Accordingly, all such numbers represent approximations that may vary depending upon the desired properties sought to be obtained by a reaction or as a result of variable experimental conditions. Therefore, within an expected range of experimental reproducibility, the term "about" in the context of the resulting data, refers to a range for data provided that may vary according to a standard deviation from the mean. As well, for experimental results provided, the resulting data may be rounded up or down to present data consistently, without loss of significant figures. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding techniques.

While the numerical ranges and parameters setting forth the broad scope of the description are approximations, the numerical values set forth in the working examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

The column chromatography system used for product purification was an ISCO CombiFlash™ brand chromatography system (manufactured by Teledyne Isco).

Synthetic Examples

Greater details of the present description are provided with reference to the following non-limiting examples, which are offered to more fully illustrate the description, but are not to be construed as limiting the scope thereof. The examples illustrate the preparation of certain compounds described herein, and the testing of these compounds in vitro and/or in vivo. Those of skill in the art will understand that the techniques described in these examples represent techniques described by the inventors to function well in the practice of the description, and as such constitute preferred modes for the practice thereof. However, those of skill in the art should appreciate in light of the present disclosure that many changes can be made to the specific methods that are disclosed and still obtain a like or similar result without departing from the spirit and scope of the description.

As used above, and throughout this description, the following abbreviations, unless otherwise indicated, shall be understood to have the following meanings:

Abbreviation Meaning

AcOH or HO Ac acetic acid

ACN or MeCN acetonitrile

Bn benzyl

BnBr benzyl bromide

BnO or OBn benzyloxy

Boc ie/t-butoxycarbonyl

Boc ₂ 0 or (Boc) ₂ 0 di-ie/ -butyl dicarbonate

[(2-di-ieri-butylphosphino-2',4',6'-triisopropyl-l,l '-biphenyl)- iBuXPhos-Pd-G3

2-(2 '-amino- Ι, -biphenyl)] palladium(II) methanesulfonate

Cbz benzyloxycarbonyl

DCE dichloroethane

DCM dichloromethane (CH ₂ C1 ₂ )

DIBAL-H diisobutylaluminium hydride Abbreviation Meaning

DIPEA N,N-diisopropylethylamine

DMF dimethyl formamide

DMA dimethylacetamide

DMAP 4-dimethylaminopyridine

DMB 2,4-dimethoxybenzyl

DMSO dimethylsulfoxide

EA or EtOAc ethyl acetate

EtOH ethanol

Et ₂ 0 diethyl ether

HC1 hydrochloric acid

HPLC high performance liquid chromatography

h/hr/hrs/min/s hour(s)(h, hr or hrs)/minute(s)(min/mins)/second(s)

K ₂ C0 ₃ potassium carbonate

KOAc potassium acetate

K ₃ P0 ₄ potassium phosphate

LAH lithium aluminium hydride

LC/MS, LCMS or : liquid chromatographic mass spectroscopy

LDA lithium diisopropylamide

LiHMDS lithium bis(trimethylsilyl)amide

di-tert-butyl(2',4',6'-triisopropyl-3,4,5,6-tetramethyl-[l

Me ₄ iBu-XPhos , - biphenyl] -2-yl)phosphine

Mel methyl iodide

MeOH methanol

Me ₂ NH or NHMe ₂ dimethyl amine

MS mass spectroscopy

N ₂ nitrogen

Na ₂ S0 ₄ sodium sulfate

NaBH(OAc) ₃ sodium triacetoxyborohydride

NaHMDS sodium bis(trimethylsilyl)amide

NBS N-bromo succinimide

NH ₄ OH ammonium hydroxide

NMO N-methylmorpholine-N-oxide

NMP N-methyl-2-pyrrolidone

n-BuLi n-butyl lithium

NMR nuclear magnetic resonance

Pd/C palladium on carbon

Pd ₂ (dba) ₃ tris(dibenzylideneacetone)dipalladium(0)

Pd(dppf)Cl ₂ [1,1 '-bis(diphenylphosphino)ferrocene] dichloropalladium(II)

Pd(PPh ₃ ) ₄ tetrakis(triphenylphosphine)palladium

Pin pinacol

psi pounds per square inch pressure

S-Phos 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl

TBDPSC1 tert-butyldiphenylchlorosilane

TBS tert-butyldimethylsilyl

TBSC1 tert-butyldimethylsilyl chloride Abbreviation Meaning

i-BuOK potassium tert-butoxide

TEA or NEt ₃ triethylamine

TFA trifluoroacetic acid

THF tetrahydrofuran

THP tetrahydro-2H-pyranyl

THPO or OTHP tetrahydro-2H-pyran-2-yl-oxy

TIPS-H or TIPSH triisopropyl silane

TLC thin layer chromatography

TMP 2,2,6,6-tetramethylpiperidinyl

2,2,6,6-tetramethylpiperidinylmagnesium chloride lithium

TMPMgCl-LiCl

chloride

TMSI trimethylsilyl iodide

TMSOK potassium trimethylsilanolate

Example 1 (Compound 411)

2-{6-[8-Azabicyclo[3.2.1]oct-3-yl(methyl)amino]pyridazin-3-y l}-5-(lH-pyrazol-4-yl)phenol hydrochloride

Step 1: 3,6-Dibromopyridazine (133.7 mg, 0.56 mmol), tert-butyl (lR,5S)-3-(methylamino)-8- azabicyclo[3.2.1]octane-8-carboxylate (85 mg, 0.28 mmol) and DIPEA (0.15 mL, 0.84 mmol) were mixed in 1 mL of ACN and heated to 100 °C for 1 h until LC-MS showed complete consumption of the starting material. The reaction mixture was concentrated and purified via column chromatography: eluting with gradient CH ₂ Cl ₂ /MeOH (0% to 30% MeOH), column: silica 4g to afford tert-butyl (lS,5 ?)-3-[(6-bromopyridazin-3-yl)-methyl-amino]-8- azabicyclo[3.2.1]octane-8-carboxylate (55 mg, 49.25% yield).

Step 2: tert-Butyl 3-[(6-bromopyridazin-3-yl)-methyl-amino]-8-azabicyclo[3.2.1] octane-8- carboxylate (55 mg, 0.14 mmol), 4-[3-(methoxymethoxy)-4-(4,4,5,5-tetramethyl-l,3,2- dioxaborolan-2-yl)phenyl]-l-tetrahydropyran-2-yl-pyrazole (68.82 mg, 0.17 mmol), Pd(dppf)Cl ₂ (10.34 mg, 0.01 mmol), K ₂ C0 ₃ (57.98 mg, 0.42 mmol) were mixed in a Schlenk tube. The reaction was degassed with N ₂ for 15 min and dioxane (2 mL) and water (0.5 mL) were added and the reaction was heated to 90 °C for 16 h. The reaction was cooled to room temperature, partitioned between EtOAc and water. The organic layers were dried over Na ₂ S0 ₄ , concentrated under vacuum, purified via column chromatography: eluting with gradient CH ₂ Cl ₂ /EtOAc (0% to 80%), column: silica 4g, to providetert-butyl (lS,5 ?)-3-[[6-[2-(methoxymethoxy)-4-(l- tetrahydropyran-2-ylpyrazol-4-yl)phenyl]pyridazin-3-yl]-meth yl-amino]-8- azabicyclo[3.2.1]octane-8-carboxylate (52 mg, 62%) as a tan solid.

Step 3: To a solution of tert-butyl (lS,5 ?)-3-[[6-[2-(methoxymethoxy)-4-(l-tetrahydropyran-2- ylpyrazol-4-yl)phenyl]pyridazin-3-yl]-methyl-amino]-8-azabic yclo[3.2.1]octane-8-carboxylate (52 mg, 0.086 mmol) in a 1 niL mixture of CH ₂ C1 ₂ and 0.5 mL of MeOH was added HC1 (4 mol/L) in 1,4-dioxane (0.06 mL). The reaction was stirred overnight. The precipitate was filtered, then dried under vacuum to provide 2-[6-[8-azabicyclo[3.2.1]octan-3- yl(methyl)amino]pyridazin-3-yl]-5-(lH-pyrazol-4-yl)phenol; hydrochloride (15 mg, 42.25% yield) as a yellow solid.

LC-MS: 377 [M+H] ⁺ . 1H NMR (500 MHz, DMSO-d ₆ ) δ: 9.37-9.51 (m, IH), 8.87-8.96 (m, IH), 8.31 (d, 7=9.8 Hz, IH), 8.12 (s, 2H), 7.74 (d, 7=8.2 Hz, 2H), 7.19-7.27 (m, 2H), 4.80-4.92 (m, IH), 4.08-4.14 (m, 3H), 3.07 (s, 3H), 2.30 (td, 7=12.6, 2.8 Hz, 2H), 1.99-2.15 (m, 4H), 1.74-1.87 (m, 2H)

Using the procedure described for Example 1 above, additional compounds described herein may be prepared by substituting the appropriate starting materials reagents, and reaction conditions, obtaining compounds such as those selected from:

Example 2 (Compound 416)

5-(5-Methyl-lH-pyrazol-4-yl)-2-{6-[methyl(2,2,6,6-tetramethy

3-yl}phenol

Step 1: 3-Methoxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-yl)phe^ trifluoromethanesulfonate (80 mg, 0.16 mmol), (tert-butyl 3-methyl-4-(4,4,5,5-tetramethyl-l,3,2- dioxaborolan-2-yl)-lH-pyrazole-l-carboxylate (59 mg, 0.19 mmol), Pd(dppf)Cl ₂ (7 mg, 0.01 mmol), K ₂ CO ₃ (66 mg, 0.48 mmol) were mixed in a Schlenk tube. The reaction was degassed with N ₂ for 15 min and dioxane (2 mL) and water (0.5 mL) were added and the reaction was heated to 90 °C for 16 h. The reaction was cooled to room temperature, partitioned between EtOAc and water. The organic layers were dried over Na ₂ S0 ₄ , concentrated under vacuum, then purified via column chromatography: eluting with gradient CH ₂ Cl ₂ /MeOH (0% to 30% MeOH), column: silica 4g to provide tert-butyl 4-(3-methoxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin- 4-yl)amino)pyridazin-3-yl)phenyl)-3-methyl-lH-pyrazole-l-car boxylate (46 mg, 54%) as light brown solid.

Step 2: A solution of tert-butyl 4-(3-methoxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4- yl)amino)pyridazin-3-yl)phenyl)-3-methyl-lH-pyrazole-l-carbo xylate (46 mg, 0.09mmol) in 2 mL of dry CH ₂ C1 ₂ was cooled in ice-water bath. Boron tribromide 1.0 M in CH ₂ C1 ₂ (0.45 mL, 0.45 mmol) was added and the reaction mixture was stirred at room temperature for 16 hours. The reaction was quenched with 2 mL of MeOH, stirred for 30 min, then concentrated and purified via column chromatography: eluting with gradient CH ₂ Cl ₂ /MeOH (2.5% NH ₄ OH) (0% to 30% MeOH/NH ₄ OH), column: silica 4g, to provide tert-butyl 2-(6-(methyl(2,2,6,6- tetramethylpiperidin-4-yl)amino)pyridazin-3-yl)-5-(3-methyl- lH-pyrazol-4-yl)phenol (20 mg, 55%) as a yellow solid.

LC-MS: 421 [M+H] ⁺ . 1H NMR (500 MHz, DMSO- ₆ ) δ: 13.74 (s, 1H), 12.63-12.71 (m, 1H), 8.20 (d, =9.5Hz, 1H), 8.03-8.04 (m, 1H), 7.86 (d, =8.0Hz, 1H), 7.73-7.75 (m, 1H), 7.36 (d, =9.5Hz, 1H), 7.03-7.06 (m, 2H), 4.90-5.05 (m, 1H), 2.92 (s, 3H), 2.43 (s, 3H), 1.43-1.54 (m, 2H), 1.15-1.43 (m, 2H), 1.14 (s, 6H), 1.09 (s, 6H) Using the procedure described for Example 2 above, additional compounds described herein may be prepared by substituting the appropriate starting materials reagents, and reaction conditions, obtaining compounds such as those selected from:

Example 3 (Compound 419)

2-{6-[Methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-5-(4-nitro-lH-pyrazol-l- yl)phenol dihydrochloride

Step 1: 3-Methoxy-4-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)ami no)pyridazin-3-yl)phenyl trifluoromethanesulfonate (335 mg, 0.67 mmol), 4-nitro-lH-pyrazole (340 mg, 4.5 mmol), Pd ₂ (dba) ₃ (67 mg, 0.07 mmol), Me ₄ tBu-XPhos (35 mg, 0.07 mmol), K ₃ P0 ₄ (368 mg, 1.73 mmol) were mixed in a Schlenk tube. The reaction was degassed with N ₂ for 15 min and dioxane (8 mL) was added and the reaction was heated to 90 °C for 16 h. The reaction was cooled to room temperature, filtered through celite, concentrated, purified via column chromatography: eluting with gradient CH ₂ Cl ₂ MeOH (0% to 30% MeOH), column: silica 12g, to provide 6-(2-methoxy- 4-(4-nitro-lH-pyrazol-l-yl)phenyl)-N-methyl-N-(2,2,6,6-tetra methylpiperidin-4-yl)pyridazin-3- amine (202 mg, 65%).

LC-MS: 466 [M+H] ⁺ . 1H NMR (500 MHz, DMSO- ₆ ) δ: 9.81-9.85 (m, IH), 8.61 (d, 7=0.6 Hz, IH), 7.91 (d, 7=8.5 Hz, IH), 7.81 (d, 7=9.8 Hz, IH), 7.73 (d, 7=1.9 Hz, IH), 7.68 (dd, 7=8.2, 2.2 Hz, IH), 7.10-7.21 (m, IH), 5.08-5.26 (m, IH), 3.96 (s, 3H), 2.95 (s, 3H), 1.59-1.75 (m, 4H), 1.40 (s, 6H), 1.33, (s, 6H), (1 hydrogen corresponding to OH or NH unobserved) Step 2: 6-(2-Methoxv-4-(4-nitro-lH-pvrazol-l-vl)phenvl)-N-methyl-N-( 2,2,6,6- tetramethylpiperidin-4-yl)pyridazin-3-amine (150 mg, 0.32 mmol), benzenethiol (33 μί, 0.32 mmol) and K ₂ CO ₃ (44 mg, 0.32 mmol) were mixed in a microwave tube. The reaction was degassed with N ₂ for 15 min and dry NMP (1.5 mL) was added. The reaction was heated in a Biotage microwave at 190 °C for 20 min, then diluted with 10 mL EtOAc, and washed with water and brine. The product was dried over Na ₂ S0 ₄ , concentrated under vacuum, then purified via column chromatography: eluting with gradient CH ₂ Cl ₂ /MeOH (0% to 30% MeOH), column: silica 4g, to provide 2-(6-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)pyridaz in-3-yl)-5-(4- nitro-lH-pyrazol-l-yl)phenol (60 mg, 42%) as a brown solid.

LC-MS: 452 [M+H] ⁺ . 1H NMR (500 MHz, DMSO- ₆ ) δ: 9.77 (s, 1H), 8.68 (d, 7=9.8 Hz, 1H), 8.62 (s, 1H), 8.27 (d, 7=8.8 Hz, 1H), 7.87-7.94 (m, 1H), 7.66 (dd, 7=8.5, 2.6 Hz, 1H), 7.64 (d, 7=2.6 Hz, 1H), 5.03-5.22 (m, 1H), 3.01 (s, 3H), 1.84-1.94 (m, 2H), 1.70-1.77 (m, 2H), 1.53 (s, 6H), 1.43 (s, 6H), (2 hydrogens corresponding to OH and NH unobserved)

Using the procedure described for Example 3 above, additional compounds described herein may be prepared by substituting the appropriate starting materials reagents, and reaction conditions, obtaining compounds such as those selected from:

Example 4 (Compound 424)

5-(lH-Pyrazol-4-yl)-2-[6-(l,2,3,6-tetrahydropyridin-4-yl)pyr idazin-3-yl]phenol trihydrochloride

Step 1: 3-Bromo-6-(2-methoxy-4-(l-(tetrahydro-2H-pyran-2-yl)-lH-pyra zol-4- yl)phenyl)pyridazine (100 mg, 0.24 mmol), (l-(tert-butoxycarbonyl)- 1,2,3, 6-tetrahydropyridin- 4-yl)boronic acid (66 mg, 0.29 mmol), PddppfCl ₂ (8 mg, 0.012 mmol), K ₂ C0 ₃ (99 mg, 0.72 mmol) were mixed in a Schlenk tube. The reaction was degassed with N ₂ for 15 min and dioxane (2 mL) and water (0.5 mL) were added and the reaction was heated to 90 °C for 16 h. The reaction was cooled to room temperature, and partitioned between EtOAc and water. The organic layers were dried over Na ₂ S0 ₄ , then concentrated under vacuum, and purified via column chromatography: eluting with gradient CH ₂ Cl ₂ /MeOH (0% to 20% MeOH), column: silica 4g, to provide 5-(lH-pyrazol-4-yl)-2-(6-(l,2,3,6-tetrahydropyridin-4-yl)pyr idazin-3-yl)phenol (102 mg, 82%) as an off-white solid.

Step 2: A solution of 5-(lH-pyrazol-4-yl)-2-(6-(l,2,3,6-tetrahydropyridin-4-yl)pyr idazin-3- yl)phenol (102 mg, 0.196 mmol) in 2 mL of dry CH ₂ C1 ₂ was cooled in ice-water bath. Boron tribromide 1.0 M in CH ₂ C1 ₂ (0.98 mL, 0.98 mmol) was added and the reaction mixture was stirred at room temperature for 16 hours. The reaction was quenched with 2 mL of MeOH, stirred for 30 min, then concentrated and purified using preparative HPLC to provide 5-(lH- pyrazol-4-yl)-2-(6-(l,2,3,6-tetrahydropyridin-4-yl)pyridazin -3-yl)phenol (41 mg, 66%) as an off- white solid.

LC-MS: 320 [M+H] ⁺ . 1H NMR (500 MHz, DMSO- ₆ ) δ: 9.19 (br S, 2H), 8.54 (d, J= 9.6Hz,

1H), 8.22, (d, =9.6Hz, 1H), 8.18 (s, 1H), 8.05 (d, =8.8Hz, 1H), 7.25-7.29 (m, 2H), 6.92 (s, 1H), 3.85-3.92 (m, 2H), 3.38-3.41 (m, 2H), 2.88-2.98 (m, 2H), (1 hydrogen corresponding to OH or NH unobserved)

Using the procedure described for Example 4 above, additional compounds described herein may be prepared by substituting the appropriate starting materials reagents, and reaction conditions, obtaining compounds such as those selected from:

Cpd Data

LC-MS: 348 [M+H] ⁺ . 1H NMR (500 MHz, DMSO-d ₆ ) δ: 10.94 (br S, 1H), 8.56 (d, /=9.6Hz, 1H), 8.26 (d, /=9.6Hz, 1H), 8.19-8.23 (m, 2H), 8.05 (d, /=8.4Hz, 1H),

425 7.26-7.31 (m, 2H), 6.93 (s, 1H), 4.07-4.13 (m, 1H), 3.85-3.91 (m, 1H), 3.70-3.74

(m, 1H), 3.22-3.30 (m, 3H), 3.08-3.14 (m, 2H), 1.33 (t, /=7.2Hz, 3H), (1 hydrogen corresponding to OH or NH unobserved)

LC-MS: 346 [M+H] ⁺ . 1H NMR (500 MHz, methanol-^) δ: 1.79 - 1.89 (m, 1H) 1.98 - 2.11 (m, 1H) 2.11 - 2.33 (m, 2H) 2.65 - 2.80 (m, 1H) 3.09 - 3.21 (m, 1H) 4.02 -

429

4.16 (m, 2H) 7.02 - 7.14 (m, 1H) 7.24 (s, 2 H) 7.85 - 7.97 (m, 1H) 8.04 (d, =9.46 Hz, 3H) 8.33 (d, =9.46 Hz, 1H)

Example 5 (Compound 427)

2-[6-(Piperidin-4-ylamino)pyridazin-3-yl]-5-(lH-pyrazol-4-yl )phenol tetrahydrochloride

Step 1: 3,6-Dibromopyridazine (500 mg, 2.1 mmol), 4-(3-methoxy-4-(4,4,5,5-tetramethyl-l,3,2- dioxaborolan-2-yl)phenyl)-l-(tetrahydro-2H-pyran-2-yl)-lH-py razole (970 mg, 2.52 mmol), Pd(dppf)Ci ₂ (77 mg, 0.11 mmol), K ₂ CO ₃ (870 mg, 6.3 mmol) were mixed in a Schlenk tube. The reaction was degassed with N ₂ for 15 min and dioxane (8 mL) and water (1 mL) were added and the reaction was heated to 90 °C for 16 h. The reaction was cooled to room temperature, partitioned between EtOAc and water. The organic layers were dried over Na ₂ S0 ₄ , concentrated under vacuum, purified via column chromatography: eluting with gradient hexanes/EtOAc (0% to 40% EtOAc), column: silica 4g, to provide 3-bromo-6-(2-methoxy-4-(l-(tetrahydro-2H-pyran- 2-yl)-lH-pyrazol-4-yl)phenyl)pyridazine (690 mg, 79%) as an off-white fluffy solid.

Step 2: 3-Bromo-6-(2-methoxy-4-(l-(tetrahydro-2H-pyran-2-yl)-lH-pyra zol-4- yl)phenyl)pyridazine (50 mg, 0.12 mmol), tert-butyl 4-aminopiperidine-l-carboxylate (36 mg, 0.18 mmol), potassium t-butoxide (41 mg, 0.36 mmol), iBuXPhos-Pd-G3 (10 mg, 0.012 mmol) were mixed in a Schlenk tube. The reaction was degassed with Ar then dry THF (2 mL) was added and the reaction was heated to 80 °C for 12 h. The reaction was cooled to room

temperature, then partitioned between EtOAc and water. The organic layers were dried over Na ₂ S0 ₄ , concentrated under vacuum, and purified via column chromatography: eluting with gradient CH ₂ Cl ₂ /MeOH (0% to 15% MeOH), column: silica 4g, to provide tert-butyl 4-((6-(2- methoxy-4-(l-(tetrahydro-2H-pyran-2-yl)-lH-pyrazol-4-yl)phen yl)pyridazin-3- yl)amino)piperidine-l-carboxylate (45 mg, 70%) as a tan solid.

Step 3: A solution of 4-((6-(2-methoxy-4-(l-(tetrahydro-2H-pyran-2-yl)-lH-pyrazol- 4- yl)phenyl)pyridazin-3-yl)amino)piperidine-l-carboxylate (45 mg, 0.084 mmol) in 2 mL of dry CH ₂ CI ₂ was cooled in an ice-water bath. Boron tribromide 1.0 M in CH ₂ CI ₂ (0.42 mL, 0.42 mmol) was added and the reaction mixture was stirred at room temperature for 16 hours. The reaction was quenched with 2 mL of MeOH, stirred for 30 min, then concentrated and purified using preparative HPLC to provide 2-(6-(piperidin-4-ylamino)pyridazin-3-yl)-5-(lH-pyrazol-4- yl)phenol (21 mg, 73%) as a yellowish solid.

LC-MS: 377 [M+H] ⁺ . 1H NMR (500 MHz, DMSO-d ₆ ) δ: 8.95 (s, 2H), 8.25 (d, 7=9.6 Hz, 1H), 8.09 (s, 2H), 7.69 (d, 7=8.8 Hz, 1H), 7.49-7.41 (m, 1H), 7.21-7.24 (m, 2H), 4.11-4.15 (m, 1H), 3.34-3.39 (m, 4H), 3.01-3.08 (m, 2H), 2.11-2.17 (m, 2H), 1.79 (q, 7=9.2 Hz, 2H)

Using the procedure described for Example 5 above, additional compounds described herein may be prepared by substituting the appropriate starting materials reagents, and reaction conditions, obtaining compounds such as those selected from:

Cpd Data

LC-MS: 349 [M+H] ⁺ . 1H NMR (500 MHz, DMSO-d ₆ ) δ: 10.53 (s, IH), 10.40 (s, IH), 9.79 (br s, IH), 9.67 (br s, IH), 8.28 (d, =9.6Hz, IH), 8.06 (s, 2H), 7.65 (d,

459 =9.6Hz, IH), 7.58 (d, =8.4Hz, IH), 7.21-7.25 (m, IH), 4.53 (q, =14Hz, 2H), 3.64 (d, =12.8Hz, IH), 3.52 (d, =12.8Hz, IH), 3.37-3.40 (m, 2H), 3.15-3.24 (m, 2H), 1.92-2.02 (m, 2H)

Example 6 (Compound 430)

6-[2,3-Difluoro-4-(lH-pyrazol-4-yl)phenyl]-N-methyl-N-(2,2,6 ,6-tetramethylpiperidin-4- yl)pyridazin-3-amine hydrochloride

Step 1: To a RBF, equipped with a N ₂ inlet, were added: 6-bromo-N-methyl-N-(2,2,6,6- tetramethyl-4-piperidyl)pyridazin-3-amine (90 mg, 0.28 mmol),4-[2,3-difluoro-4-(4,4,5,5- tetramethyl-l,3,2-dioxaborolan-2-yl)phenyl]-l-tetrahydropyra n-2-yl-pyrazole (128.8 mg, 0.33 mmol), Pd(PPh ₃ ) ₄ (31.8 mg, 0.03 mmol), Na ₂ C0 ₃ (87.43 mg, 0.83 mmol). The reaction was degassed with N ₂ for 15 min then dioxane (8 mL) and water (2 mL) were added. The reaction was heated to 90 °C for 16 h, then cooled to room temperature, and partitioned between EtOAc and water. The organic layers were dried over Na ₂ S0 ₄ , concentrated on a rotavap, and purified via column chromatography: eluting with gradient CH ₂ Cl ₂ /MeOH (0% to 30%), column: silica 4g to provide 6-(2,3-Difluoro-4-(l-(tetrahydro-2H-pyran-2-yl)-lH-pyrazol-4 -yl)phenyl)-N- methyl-N-(2,2,6,6-tetramethylpiperidin-4-yl)pyridazin-3-amin e (88 mg, 63%) as a grey solid. Step 2: 6-[2,3-Difluoro-4-(l-tetrahydropyran-2-ylpyrazol-4-yl)phenyl ]-N-methyl-N-(2,2,6,6- tetramethyl-4-piperidyl)pyridazin-3-amine (88 mg, 0.17 mmol) was dissolved in MeOH (2 mL) and 4M HC1 in dioxane (90 μί, 0.34 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 30 min until LC-MS showed complete consumption of starting material. The reaction mixture was concentrated under reduced pressure to provide 6-(2,3- difluoro-4-(lH-pyrazol-4-yl)phenyl)-N-methyl-N-(2,2,6,6-tetr amethylpiperidin-4-yl)pyridazin-3- amine hydrochloride salt.

LC-MS: 427 [M+H] ⁺ . 1H NMR (500 MHz, DMSO- ₆ ) δ: 9.21-9.33 (m, IH), 8.27-8.43 (m, IH), 8.20 (s, 2H), 8.01 (d, =9.8 Hz, IH), 7.60-7.79 (m, 3H), 5.01-5.14 (m, IH), 3.05 (s, 3H), 2.10 (td, =13.2, 1.6 Hz, 2H), 1.79 (dd, =12.9, 4.1 Hz, 2H), 1.55 (s, 6H), 1.50 (s, 6H) Using the procedure described for Example 6 above, additional compounds described herein may be prepared by substituting the appropriate starting materials reagents, and reaction conditions, obtaining compounds such as those selected from:

Cpd Data

LC-MS: 379 [M+H] ⁺ . 1H NMR (500 MHz, DMSO-d ₆ ) δ: 8.42 (s, IH), 8.28 (dd, 7=1.6, 0.9 Hz, IH), 8.03 (dd, 7=9.1, 1.6 Hz, IH), 7.95 (s, IH), 7.67 (d, 7=9.1 Hz,

442 IH), 7.14 (d, 7=9.1 Hz, IH), 5.03-5.17 (m, IH), 4.19 (s, 3H), 2.94 (s, 3H), 1.49-1.58 (m, 2H), 1.37-1.48 (m, 2H), 1.27 (s, 6H), 1.10 (s, 6H), (1 hydrogen corresponding to NH unobserved)

LC-MS: 366 [M+H] ⁺ . 1H NMR (500 MHz, methanol-^) δ: 8.35 (s, IH), 8.31 (dd, 7=1.6, 0.9 Hz, IH), 8.11 (d, 7=9.1 Hz, IH), 7.99 (dd, 7=9.1, 1.9 Hz, IH), 7.75 (dt,

443 7=9.1, 0.9 Hz, IH), 7.21 (d, 7=9.5 Hz, IH), 5.81 (tt, 7=11.2, 4.1 Hz, IH), 4.27 (s, 3H), 2.28 (dd, 7=12.6, 4.1 Hz, 2H), 1.48 (t, 7=12.3 Hz, 2H), 1.41 (s, 6H), 1.30 (s, 6H), (1 hydrogen corresponding to NH unobserved)

LC-MS: 379 [M+H] ⁺ . 1H NMR (500 MHz, acetone- ₆ ) δ: 8.52 (dt, 7=7.0, 1.1 Hz, IH), 8.13 (dt, 7=8.8, 1.3 Hz, IH), 7.66 (d, 7=9.8 Hz, IH), 7.28 (ddd, 7=9.0, 6.8, 1.3

445 Hz, IH), 7.13 (d, 7=9.5 Hz, IH), 6.89 (td, 7=6.9, 1.4 Hz, IH), 5.22 (tt, 7=12.3, 3.5 Hz, IH), 3.04 (s, 3H), 2.63 (s, 3H), 1.67 (dd, 7=12.3, 3.5 Hz, 2H), 1.56 (t, 7=12.3 Hz, 2H), 1.36 (s, 6H), 1.18 (s, 6H), (1 hydrogen corresponding to NH unobserved)

LC-MS: 352 [M+H] ⁺ . 1H NMR (500 MHz, acetone- ₆ ) δ: 9.14 (dd, 7=1.6, 0.9 Hz, IH), 7.98 (dd, 7=9.5, 1.9 Hz, IH), 7.94 (t, 7=0.9 Hz, IH), 7.89 (d, 7=9.5 Hz, IH),

446 7.63 (dt, 7=9.5, 0.8 Hz, IH), 7.60 (d, 7=1.3 Hz, IH), 7.14 (d, 7=9.5 Hz, IH), 5.34 (tt, 7=12.6, 3.5 Hz, IH), 1.67 (dd, 7=12.3, 3.8 Hz, 2H), 1.55 (t, 7=12.1 Hz, 2H), 1.36 (s, 6H), 1.17 (s, 6H), (1 hydrogen corresponding to NH unobserved)

LC-MS: 394 [M+H] ⁺ . 1H NMR (500 MHz, acetone- ₆ ) δ: 8.47 (d, 7=2.5 Hz, IH), 8.05 (d, 7=9.1 Hz, IH), 7.98 (d, 7=8.5 Hz, IH), 7.76 (d, 7=1.9 Hz, IH), 7.70 (d, 7=2.2 Hz, IH), 7.59 (dd, 7=8.5, 2.2 Hz, IH), 7.06 (d, 7=9.1 Hz, IH), 6.57 (dd,

447

7=2.4, 1.7 Hz, IH), 5.85 (tt, 7=11.3, 4.1 Hz, IH), 2.21 (dd, 7=12.1, 3.9 Hz, 2H), 2.04-2.08 (m, 2H), 1.35 (s, 6H), 1.18 (s, 6H), (2 hydrogens corresponding to OH and NH unobserved)

LC-MS: 409 [M+H] ⁺ . 1H NMR (500 MHz, acetone- ₆ ) δ: 7.59 (dd, 7=8.5, 6.0 Hz, IH), 7.46 (s, 2H), 7.31 (dd, 7=10.1, 2.5 Hz, IH), 7.15 (td, 7=8.5, 2.5 Hz, IH), 7.04

452 (d, 7=9.5 Hz, IH), 6.91 (d, 7=9.5 Hz, IH), 5.23 (tt, 7=12.3, 2.8 Hz, IH), 3.00 (s, 3H), 1.65 (dd, 7=12.3, 3.5 Hz, 2H), 1.51 (t, 7=12.1 Hz, 2H), 1.33 (s, 6H), 1.15 (s, 6H), (2 hydrogens corresponding to NH unobserved)

LC-MS: 344 [M+H] ⁺ . 1H NMR (500 MHz, methanol-^) δ: 8.17 (d, 7=9.5 Hz, IH), 7.66 (d, 7=8.8 Hz, IH), 7.19 (d, 7=9.5 Hz, IH), 6.44 (dd, 7=8.7, 2.4 Hz, IH), 6.41

455 (d, 7=2.5 Hz, IH), 5.71 (tt, 7=11.0, 3.8 Hz, IH), 2.23 (dd, 7=12.6, 4.1 Hz, 2H), 1.40- 1.47 (m, 2H), 1.39 (s, 6H), 1.27 (s, 6H), (3 hydrogens corresponding to OH and NH unobserved) Cpd Data

LC-MS: 425 [M+H] ⁺ . 1H NMR (500 MHz, DMSO-d ₆ ) δ: 9.23-9.39 (m, 1H), 8.39- 8.52 (m, 1H), 8.26 (s, 2H), 8.00-8.08 (m, 1H), 7.93 (s, 1H), 7.81-7.85 (m, 1H), 7.78

456 (d, 7=7.9 Hz, 1H), 7.63 (d, 7=8.2 Hz, 1H), 4.95-5.03 (m, 1H), 3.08 (s, 3H), 2.13 (t, 7=12.9 Hz, 2H), 1.81 (dd, 7=12.9, 3.5 Hz, 2H), 1.56 (s, 6H), 1.52 (s, 6H)

LC-MS: 414 [M+H] ⁺ . 1H NMR (500 MHz, DMSO- ₆ ) δ: 8.70-9.36 (m, 1H), 8.29 (s, 2H), 7.85 (d, 7=9.1 Hz, 1H), 7.60 (d, 7=9.5 Hz, 1H), 7.33-7.39 (m, 1H), 5.59-5.68

458 (m, 1H), 2.24-2.33 (m, 2H), 1.72-1.82 (m, 2H), 1.50 (s, 6H), 1.48 (s, 6H), (2

hydrogens corresponding to NH unobserved)

Example 7 (Compound 434)

6-[2-Methoxy-6-(lH-pyrazol-4-yl)pyridin-3-yl]-N-methyl-N-(2, 2,6,6-tetramethylpiperidin-4- yl)pyridazin-3-amine hydrochloride

6-(2-Methoxy-6-(l-(tetrahydro-2H-pyran-2-yl)-lH-pyrazol-4-yl )pyridin-3-yl)-N-methyl-N- (2,2,6, 6-tetramethylpiperidin-4-yl)pyridazin-3-amine (6 mg) was dissolved in 1 mL of 4N

HCl/dioxane and the resulting mixture was stirred at RT for 20 minutes. The mixture was evaporated and triturated with ether to provide 6-(2-methoxy-6-(lH-pyrazol-4-yl)pyridin-3-yl)-

N-methyl-N-(2,2,6,6-tetramethylpiperidin-4-yl)pyridazin-3 -amine 4 mg, 75%).

LC-MS: 422 [M+H] ⁺ . 1H NMR (500 MHz, methanol-^) δ: 8.42 - 8.47 (m, 1H), 8.33 - 8.42 (m, 2 H), 8.09 - 8.17 (m, 1H), 7.99 - 8.08 (m, 1H), 7.50 - 7.56 (m, 1H), 5.0 (m, 1H), 4.16 (s, 3H), 3.20 (s, 3H), 1.94 - 2.15 (m, 4H), 1.65 (s, 6H), 1.57 (s, 6H)

Example 8 (Compound 460)

3-{6-[Methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]pyridaz in-3-yl}-6-(lH-pyrazol-4- yl)pyridin-2-ol hydrochloride

Step 1: 6-Chloro-N-methyl-N-(2,2,6,6-tetramethylpiperidin-4-yl)pyrid azin-3-amine (280 mg, 1.0 mmol) was dissolved in 10 mL, a mixture of dioxane and water (4: 1). To the solution was added sodium carbonate (190 mg, 3 eq), (6-chloro-2-methoxypyridin-3-yl)boronic acid (190 mg, 1 eq) and Pd(Ph ₃ P)4 (70 mg, 0.1 eq). The reaction mixture was stirred at 90 °C for 16 h, then applied to a column and purified using DCM/MeOH to yield (133 mg, 55%) 6-(6-chloro-2- methoxypyridin-3-yl)-N-methyl-N-(2,2,6,6-tetramethylpiperidi n-4-yl)pyridazin-3-amine.

LC-MS: 390 [M+H] ⁺ . 1H NMR (500 MHz, DMSO-d ₆ ) δ: 8.25 (d, J=7.88 Hz, 1H), 7.83 (d, J=9.77 Hz, 1H), 7.24 (d, J=7.88 Hz, 1H), 7.11 (d, J=9.77 Hz, 1H), 5.00 - 5.24 (m, 1H), 3.93 (s, 3 H), 2.87 - 2.96 (m, 3H), 1.40 - 1.57 (m, 4H), 1.21 - 1.29 (m, 7H), 1.10 (br s, 6H

Step 2: 6-(6-Chloro-2-methoxypyridin-3-yl)-N-methyl-N-(2,2,6,6-tetra methylpiperidin-4- yl)pyridazin-3-amine (90 mg) was dissolved in a mixture of dioxane and water (4: 1, 5 mL). To the solution was added sodium carbonate (100 mg, 3 eq), l-(tetrahydro-2H-pyran-2-yl)-4- (4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-lH-pyrazole (70 mg, 1.1 eq) and Pd(Ph ₃ P) ₄ (27 mg, 0.1 eq). The reaction mixture was stirred at 90 °C for 16 h, then purified by column chromatography using DCM/MeOH to yield 80 mg (68%) of 6-(2-methoxy-6-(l-(tetrahydro-2H- pyran-2-yl)-lH-pyrazol-4-yl)pyridin-3-yl)-N-methyl-N-(2,2,6, 6-tetramethylpiperidin-4- yl)pyridazin-3-amine.

Step 3: 6-(2-Methoxv-6-(l-(tetrahvdro-2H-pvran-2-vl)-lH-pvrazol-4-vl )pvridin-3-vl)-N-methvl-

N-(2,2,6,6-tetramethylpiperidin-4-yl)pyridazin-3-amine (45 mg) was dissolved in 4 mL of 4N HCl/dioxane and the resulting mixture was heated for 2 hours at 60 °CF. The resulting mixture was evaporated and triturated with ether to provide 3-(6-(methyl(2,2,6,6-tetramethylpiperidin-4- yl)amino)pyridazin-3-yl)-6-(lH-pyrazol-4-yl)pyridin-2-ol (24 mg, 61%).

LC-MS: 408 [M+H] ⁺ ; 1H NMR (500 MHz, methanol-^) δ: 8.62 - 8.69 (m, 1H), 8.55 - 8.61 (m, 1H), 8.39 (s, 2H), 7.95 - 8.06 (m, 1H), 7.04 - 7.14 (m, 1H), 5.02 - 5.24 (m, 1H), 3.18 (s, 3H), 2.03 (s, 4H), 1.67 (s, 6H), 1.57 (s, 6H)

Using the procedure described for Example 8 above, an additional compound described herein may be prepared by substituting the appropriate starting materials reagents, and reaction conditions, obtaining compounds such as those selected from:

Biological Examples The following in vitro biological examples demonstrate the usefulness of the compounds of the present description for treating Huntington's disease.

To describe in more detail and assist in understanding the present description, the following non-limiting biological examples are offered to more fully illustrate the scope of the description and are not to be construed as specifically limiting the scope thereof. Such variations of the present description that may be now known or later developed, which would be within the purview of one skilled in the art to ascertain, are considered to fall within the scope of the present description and as hereinafter claimed.

Example 1

Development and Validation of Meso Scale Discovery (MSD) Assay to Quantify Mutant and Total Huntingtin Protein (HTT) - Best Pair Analysis for Endogenous HTT Detection

To identify orally bioavailable small molecules useful for HTT reduction, high throughput ELISA methods to detect and measure both total HTT (wild-type and mutant)(tHTT) and mutant HTT (mHTT) in cells and tissues from HD patients and animal models are needed. The method described herein permits relatively high throughput protein measurement of tHTT and mHTT levels in cells and tissues from HD patients and in HD animal models. The ELISA method described herein enables screening of molecules for their ability to decrease the level of HTT and to identify and optimize small molecules for use in treating HD.

To determine the combination of antibodies that detect HTT (wild type and mutant) in a sensitive, high throughput format, multiple commercially available antibodies (Table 1) were screened in capture/detection combinations.

Protocol for Best Pair Analysis for Antibody Comparison in Detecting Total and Mutant HTT in Cells

1. Cells were cultured in a cell culture-compatible 96-well plate.

2. The medium was removed and 50-100 of lysis buffer per well (composition described below) was added to cells to provide a "cell lysate". The plate was placed on a shaker at

4° C for 30 minutes, then stored at -20° C.

3. A Capture Antibody Diluent was prepared by diluting the capture antibody in PBS for standard plates as described in the plate layout, then 30 of the Capture Antibody Diluent was added per well. The plate was sealed and incubated at 4° C overnight.

4. The plate was washed 3X with 200 of Wash Buffer. Blocking Buffer (150 μΐ, per well) was added, then the plate was sealed and incubated on a plate shaker for 3-4 hours at room temperature (RT).

5. The Blocking Buffer was decanted and the plate was washed 3X with 200 of Wash Buffer. The cell lysate (25 μί per well) was then added. The plate was sealed and incubated at 4° C overnight. 6. A First Detection Antibody Diluent was prepared by diluting a first detection antibody for pairing in an Assay Antibody Diluent. The plate was washed 3X with 200 of Wash Buffer, then 25 of the First Detection Antibody Diluent was added per well. The plate was sealed and incubated on a plate shaker for 1 hour at RT.

7. A Second Detection Antibody Diluent was prepared by diluting a second detection

antibody for pairing in an Assay Antibody Diluent. The plate was washed 3X with 200 μL of Wash Buffer, then 25 of the Second Detection Antibody Diluent was added per well. The plate was sealed and incubated on a plate shaker for 1 hour at RT.

8. The Read Buffer was diluted 4X. The plate was washed 3X with 200 of Wash Buffer, then 150 μί of the Read Buffer was added per well. The plate were read immediately following.

The various commercially available antibodies screened in the Best Pair Analysis, providing different capture/detection combinations are shown in Table 1. The capture/detection antibody pairs evaluated are shown in Table 2. The two antibody pairs that gave the maximum spread of values (higher signal to noise ratio) were selected for polyglutamine-expanded (mHTT) and total human HTT detection.

Table 1

Table 2 Pair HTT MSD ID Signal to Noise ratio

Capture/Detection Total MAB2166/MAB2174 95

Capture/Detection Total MAB2166/sc-8767 6

Capture/Detection Total sc-8767/#5656 5

Capture/Detection Total MAB2166/#5656S 483

Capture/Detection Mutant MAB5374/#5656S 8

Capture/Detection Mutant MAB 1574/#5656S 25

Capture/Detection Mutant P1874/#5656S 20

Capture/Detection Mutant MW1/#5656S 45

Characteristics for Best Pair capture/detection antibody pairs are those combinations that give minimum background and maximum signal. Such highly sensitive ELISA assays would be useful to detect HTT in the context of drug discovery for screening agents (small and large molecules and gene therapies) and for use in detecting HTT as a biomarker in clinical studies. Such capture/detection antibody pairs for quantifying total HTT are selected from

MAB2166/MAB2174 and MAB2166/#5656S. Such capture/detection antibody pairs for quantifying mutant HTT are selected from MAB 1574/#5656S, P1874/#5656S and

MW1/#5656S. The antibody pair for mHTT (MW1/#5656S) and the other for total HTT (MAB2166/#5656S) from this analysis were further optimized and validated to provide high- throughput assays that enabled HTT detection in patient fibroblasts and lymphocytes.

The Endogenous Huntingtin Protein assay used in Example 2 was developed using the Best Pair antibodies identified in Table 2, providing highly sensitive, high-throughput detection assays for polyglutamine-expanded (mHTT) and total human HTT in multiple cell systems. The platform used for the assay is the ELISA-based Meso Scale Discovery (MSD)

electrochemiluminescence assay platform.

Example 2

Endogenous Huntingtin Protein Assay

Meso Scale Discovery (MSD) 96-well or 384-well plates were coated overnight at 4°C with MW1 (expanded polyglutamine) or MAB2166 monoclonal antibody (for capture) at a concentration of 1 μg/mL in PBS (30 μΐ _^ per well). Plates were then washed three times with

300 wash buffer (0.05% Tween-20 in PBS) and blocked (100 blocking buffer; 5% BSA in PBS) for 4-5 hours at room temperature with rotational shaking and then washed three times with wash buffer. Samples (25 μί) were transferred to the antibody-coated MSD plate and incubated overnight at 4°C. After removal of the lysates, the plate was washed three times with wash buffer, and 25 μΐ _^ of #5656S (Cell signaling; rabbit monoclonal) secondary antibody (diluted to 0.25 μg/mL in 0.05% Tween-20 in blocking buffer) was added to each well and incubated with shaking for lHour at room temperature. Following incubation with the secondary antibody, the wells were rinsed with wash buffer after which 25 μΐ _^ of goat anti-rabbit SULFO TAG secondary detection antibody (required aspect of the MSD system) (diluted to 0.25 μg/mL in 0.05% Tween- 20 in blocking buffer) was added to each well and incubated with shaking for 1 hour at room temperature. After rinsing three times with wash buffer, 150 μΐ _^ of read buffer T with surfactant (MSD) were added to each empty well, and the plate was imaged on a SI 6000 imager (MSD) according to manufacturers' instructions provided for 96- or 384- well plates. The resulting IC ₅₀ values (μΜ) for compounds tested are shown in Table 3.

As shown in Table 3, test compounds described herein had the following IC ₅₀ values, an IC ₅₀ value between > 3 μΜ and < 9 μΜ is indicated by a single star (*), an IC ₅₀ value between > 1 μΜ and < 3 μΜ is indicated by two stars (**), an IC ₅₀ value between > 0.5 μΜ and < 1 μΜ is indicated by three stars (***), an IC ₅₀ value between > 0.1 μΜ and < 0.5 μΜ is indicated by four stars (****) and an IC ₅₀ value of < 0.1 μΜ is indicated by five stars (*****).

Table 3

Cpd IC50 Cpd ICso Cpd ICso

16 * 413 ***** 441 *

26 **** 414 ***** 442 *

31 **** 415 ***** 443 *

460 * 416 ***** 444 *

39 * 417 ***** 445 *

44 ***** 418 ***** 446 *

46 ***** 419 ***** 447 *

47 **** 420 ***** 448 *

48 ***** 421 ***** 449 *

51 ***** 422 ***** 450 *

63 ***** 423 ***** 451 *

64 ***** 424 **** 451 *

170 ***** 425 **** 452 *

176 ***** 426 **** 454 * Cpd ICso Cpd ICso Cpd ICso

200 ***** 427 **** 455 *

207 **** 428 **** 456 *

212 ***** 429 **** 456 *

218 ***** 430 **** 456 *

258 **** 431 **** 457 *

307 **** 432 **** 458 *

315 ***** 433 **** 459 *

318 ***** 434 *** 460 *

348 ***** 435 *** 461 *

350 ***** 436 *** 462 *

352 **** 437 ** 463 *

393 ***** 438 ** 464 *

411 ***** 439 ** 465 *

412 ***** 440 *

Without regard to whether a document cited herein was specifically and individually indicated as being incorporated by reference, all documents referred to herein are incorporated by reference into the present application for any and all purposes to the same extent as if each individual reference was fully set forth herein.

Having now fully described the subject matter of the claims, it will be understood by those having ordinary skill in the art that the same can be performed within a wide range of equivalents without affecting the scope of the subject matter or embodiments described herein. It is intended that the appended claims be interpreted to include all such equivalents.