Substituted imidazo[1,5-a]pyrazines as Btk inhibitors

1. A compound of Formula I:

or a pharmaceutically acceptable salt thereof,

wherein:

Ring A is selected from the group consisting of:

R 1 is (1-6C)alkyl, (1-6C)haloalkyl or cyclopropyl;

R 2 is (1-3C)alkoxy or halogen;

R 3 is (1-3C)alkyl;

x is 0, 1 or 2;

T is C(R a ) 2 , NR c or a bond;

U is C(R b ) 2 , O or NR d ; and

R a , R b , R c , and R d are each independently selected from H and (1-3C)alkyl.

2. The compound of claim 1 , wherein the compound has Formula Ia:

or a pharmaceutically acceptable salt thereof.

3. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein:

R 1 is CF 3 ;

R 3 is CH 3 ; and

x is 1.

4. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein the compound is selected from the group consisting of;

(6S,8aR)-6-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-6-methyltetrahydro-1H-oxazolo[3,4-a]pyridin-3(5H)-one;

4-(8-amino-3-((6S,8aR)-6-methyl-3-oxohexahydro-1H-oxazolo[3,4-a]pyridin-6-yl)imidazo[1,5-a]pyrazin-1-yl)-3-ethoxy-N-(4-(trifluoromethyl)pyridin-2-yl)benzamide;

4-(8-amino-3-((6S,8aR)-6-methyl-3-oxohexahydro-1H-oxazolo[3,4-a]pyridin-6-yl)imidazo[1,5-a]pyrazin-1-yl)-3-ethoxy-N-(1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)benzamide;

(7S,9aR)-7-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropyl-7-methylhexahydro-1H-pyrido[1,2-a]pyrazin-4(6H)-one;

4-(8-amino-3-((7S,9aR)-2-isopropyl-7-methyl-4-oxooctahydro-1H-pyrido[1,2-a]pyrazin-7-yl)imidazo[1,5-a]pyrazin-1-yl)-3-ethoxy-N-(4-(trifluoromethyl)pyridin-2-yl)benzamide bis(2,2,2-trifluoroacetate);

4-(8-amino-3-((7S,9aR)-2-isopropyl-7-methyl-4-oxooctahydro-1H-pyrido[1,2-a]pyrazin-7-yl)imidazo[1,5-a]pyrazin-1-yl)-3-ethoxy-N-(1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)benzamide bis(2,2,2-trifluoroacetate);

6R,8aS)-6-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-6-methyltetrahydro-1H-oxazolo[3,4-a]pyridin-3(5H)-one;

(7R,9aS)-7-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropyl-7-methylhexahydro-1H-pyrido[1,2-a]pyrazin-4(6H)-one;

4-(8-amino-3-((6R,8aS)-6-methyl-3-oxooctahydroindolizin-6-yl)imidazo[1,5-a]pyrazin-1-yl)-3-ethoxy-N-(4-(trifluoromethyl)pyridin-2-yl)benzamide;

4-(8-amino-3-((6R,8aS)-6-methyl-3-oxooctahydroindolizin-6-yl)imidazo[1,5-a]pyrazin-1-yl)-3-methoxy-N-(4-(trifluoromethyl)pyridin-2-yl)benzamide;

7-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2,7-diethyloctahydro-1H-pyrido[1,2-c]pyrimidin-1-one;

7-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2,7-diethyloctahydro-1H-pyrido[1,2-c]pyrimidin-1-one;

7-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2,7-dimethyloctahydro-1H-pyrido[1,2-c]pyrimidin-1-one; and

7-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2,7-dimethyloctahydro-1H-pyrido[1,2-c]pyrimidin-1-one.

5. A pharmaceutical composition comprising a compound of claim 1 , or a pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable carriers.

6. The pharmaceutical composition of claim 5 , wherein the pharmaceutical composition further comprises at least one additional therapeutically active agent.

7. A method for inhibiting Bruton's tyrosine kinase activity in a subject, comprising administering to the subject a therapeutically effective amount of the compound of claim 1 .

8. The method of claim 7 , wherein the subject has a Bruton's tyrosine kinase mediated disorder selected from the group consisting of rheumatoid arthritis, psoriatic arthritis, infectious arthritis, progressive chronic arthritis, deforming arthritis, osteoarthritis, traumatic arthritis, gouty arthritis, Reiter's syndrome, polychondritis, acute synovitis, acute spondylitis, glomerulonephritis with nephrotic syndrome, glomerulonephritis without nephrotic syndrome, an autoimmune hematologic disorder, hemolytic anemia, aplasic anemia, idiopathic thrombocytopenia, idiopathic neutropenia, autoimmune gastritis, an autoimmune inflammatory bowel disease, ulcerative colitis, Crohn's disease, host versus graft disease, allograft rejection, chronic thyroiditis, Graves' disease, schleroderma, type I diabetes, type II diabetes, acute active hepatitis, chronic active hepatitis, pancreatitis, primary billiary cirrhosis, myasthenia gravis, multiple sclerosis, systemic lupus erythematosis, psoriasis, atopic dermatitis, contact dermatitis, eczema, skin sunburns, vasculitis, chronic renal insufficiency, Stevens-Johnson syndrome, inflammatory pain, idiopathic sprue, cachexia, sarcoidosis, Guillain-Barré syndrome, uveitis, conjunctivitis, kerato conjunctivitis, otitis media, periodontal disease, pulmonary interstitial fibrosis, asthma, bronchitis, rhinitis, sinusitis, pneumoconiosis, pulmonary insufficiency syndrome, pulmonary emphysema, pulmonary fibrosis, silicosis, chronic inflammatory pulmonary disease and chronic obstructive pulmonary disease.

9. The method of claim 8 , wherein the subject has a Bruton's tyrosine kinase mediated disorder selected from the group consisting of rheumatoid arthritis, psoriatic arthritis and osteoarthritis.