Purine inhibitors of human phosphatidylinositol 3-kinase delta

1. A compound of Formula (I):

or a pharmaceutically acceptable salt thereof, wherein

A is selected from:

wherein A is substituted with 0, 1, 2, or 3 R 4 , each

R 4 is independently selected from C 1 -C 10 alkyl, C 1-10 haloalkyl, C 3-12

heterocycloalkylC 0-6 alkyl, C 3-12 cycloalkyl(C 0-6 alkyl), amino,

C 3-12 cycloalkyl(C 0-6 alkyl)aminocarbonyl, C 1-6 alkylamino(C 0-6 alkyl),

C 3-12 heterocycloalkylcarbonyl(C 0-6 alkyl), C 1-10 alkylcarbonyl(C 0-6 alkyl),

C 3-12 cycloalkylcarbonyl(C 0-6 alkyl), C 1-10 alkylcarboxy, or

C 1-10 alkyloxy(C 0-6 alkyl), wherein each R 4 is independently substituted by 0, 1, 2, or

3 R 5 independently selected from halogen, hydroxy, C 1-6 alkyl, C 1-4 alkoxy, or

C 1-6 haloalkyl;

each R 1 and R 2 is independently selected from: hydrogen, or cyano provided that only one of

R 1 or R 2 is cyano and the other is hydrogen; and

R 3 is hydrogen, C 1-6 haloalkyl, or C 1-6 alkyl.

2. The compound of claim 1 , wherein A is selected from

and wherein A is substituted with 0, 1, 2, or 3 R 4 .

3. The compound of claim 2 , wherein A is selected from

and wherein A is substituted with 0, 1, 2, or 3 R 4 .

4. The compound of claim 1 , wherein each R 4 is independently selected from C 1-C10 alkyl, C 1-10 haloalkyl, C 3-12 heterocycloalkylC 0-6 alkyl having 1, 2 or 3 heteroatoms selected from nitrogen or oxygen, C 3-12 cycloalkyl(C 0-6 alkyl), amino, C 3-12 cycloalkyl(C 0-6 alkyl)aminocarbonyl, C 1-6 alkylamino(C 0-6 alkyl), C 3-12 heterocycloalkylcarbonyl(C 0-6 alkyl) having 1, 2 or 3 heteroatoms selected from nitrogen or oxygen, C 1-10 alkylcarbonyl(C 0-6 alkyl), C 3-12 cycloalkylcarbonyl(C 0-6 alkyl), C 1-10 alkylcarboxy, or C 1-10 alkyloxy(C 0-6 alkyl), wherein each R 4 is independently substituted by 0, 1, 2, or 3 R 5 .

5. The compound of claim 4 , wherein each R 4 is independently selected from cyclopropylmethyl, cyclobutylmethyl, 2,2,2-trifluoroethyl, propyl, oxetanylmethyl, 2,2,2-trifluoro-l-methylethyl, methylaminoethyl, methoxyethyl, cyclopropylaminocarbonyl, ethylcarbonyl, ethyl, isobutyl, methyl, morpholinyl, cyclopropylcarbonyl, cyclobutylcarbonyl, piperidinyl, pyrrolidinylcarbonyl, 2-oxa-6-azaspiro[3,3]heptylcarbonyl, (cyclopropylmethyl)aminocarbonyl, azetidinylcarbonyl, and methylcarboxy, wherein each R 4 is independently substituted by 0, 1, 2, or 3 R 5 .

6. The compound of claim 1 , wherein each R 5 is independently selected from halogen, C 1-6 alkyl, or C 1-4 alkoxy.

7. The compound of claim 1 , wherein each R 5 is independently selected from fluoro, C 1-3 alkyl, or C 1-4 alkoxy.

8. The compound claim 1 , wherein R 3 is selected from methyl, ethyl, propyl, butyl, pentyl, difluoromethyl, trifluoromethyl, trifluoroethyl or hydrogen.

9. The compound claim 1 , wherein R 3 is selected from methyl, difluoromethyl, or hydrogen.

10. The compound according to claim 1 , or a pharmaceutically acceptable salt thereof, wherein the compound is selected from:

5-[1-(cyclopropylmethyl)-2-oxo-1,8-diazaspiro[4.5]dec-8-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-{1-[(3-methyloxetan-3-yl)methyl]-2-oxo-3-oxa-1,8-diazaspiro[4.5]dec-8-yl}-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[1-(cyclopropylmethyl)-2-oxo-1,3,8-triazaspiro[4.5]dec-8-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-{1-(cyclopropylmethyl)-3-[2-(dimethylamino)ethyl]-2-oxo-1,3,8-triazaspiro[4.5]dec-8-yl}-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-{3-[2-(dimethylamino)ethyl]-2-oxo-1-(2,2,2-trifluoro-1-methylethyl)-1,3,8-triazaspiro [4.5]dec-8-yl}-3 -(1 -methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[1-(cyclopropylmethyl)-2,2-dioxido-2-thia-1,3,8-triazaspiro [4.5]dec-8-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[4-(cyclopropylmethyl)-2-oxo-3-oxa-1,8-diazaspiro[4.5]dec-8-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-(4-ethyl-3-oxo-2,8-diazaspiro[4.5]dec-8-yl)-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[1-(cyclopropylmethyl)-3-(2-methoxyethyl)-2-oxo-1,3,8-triazaspiro[4.5]dec-8-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[1-(2-methylpropyl)-3-oxo-2-oxa-4,9-diazaspiro[5.5]undec-9-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

3-(1-methyl-1H-pyrazol-4-yl)-5-[2-oxo-1-(2,2,2-trifluoroethyl)-1,3,8-triazaspiro[4.5]dec-8-yl]pyrazine-2-carbonitrile;

5[1-(cyclopropylmethyl)-2-oxo-3-oxa-1,8-diazaspiro[4.5]dec-8-yl]-3-[1-(difluoromethyl)-1H-pyrazol-4-yl]pyrazine-2-carbonitrile;

3-[(3R)-4-(cyclopropylcarbonyl)-3-methylpiperazin-1-yl]-5-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[(3R)-3-methyl-4-{[(1R,2R)-2-methylcyclopropyl]carbonyl}piperazin-1-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[(3R)-4-(cyclopropylcarbonyl)-3-methylpiperazin-1-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

(2R)-4-[5-cyano-6-(1-methyl-1H-pyrazol-4-yl)pyrazin-2-yl]-N-cyclopropyl-2-methylpiperazine-1-carboxamide;

3-[1-(difluoromethyl)-1H-pyrazol-4-yl]-5-[(3R)-3-methyl-4-{[(1R,2R)-2-methylcyclopropyl]carbonyl}piperazin-1-yl]pyrazine-2-carbonitrile;

5-[(3R)-4-(cyclopropylcarbonyl)-3-methylpiperazin-1-yl]-3-[1-(˜2˜H_3_)methyl-1H-pyrazol-4-yl]pyrazine-2-carbonitrile;

5-[(3R)-4-(cyclopropylcarbonyl)-3-(2-methylpropyl)piperazin-1-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-{1-[(3,3-difluorocyclobutyl)methyl]-2-oxo-1,8-diazaspiro[4.5]dec-8-yl}-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

3-(1-methyl-1H-pyrazol-4-yl)-5-[2oxo-1-(2,2,2-trifluoroethyl)-1,8-diazaspiro[4.5]dec-8-yl]pyrazine-2-carbonitrile;

3-(1-methyl-1H-pyrazol-4-yl)-5-(2-oxo-1-propyl-3-oxa-1,8-diazaspiro[4.5]dec-8-yl)pyrazine-2-carbonitrile;

5[1-(cyclobutylmethyl)-2-oxo-3-oxa-1,8-diazaspiro[4.5]dec-8-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[1-(cyclopropylmethyl)-2-oxo-4-oxa-1,9-diazaspiro[5.5]undec-9-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-(4-methyl-4-morpholin-4-ylpiperidin-1-yl)-3-(1-methy1-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-(4′-methyl-1,4′-bipiperidin-1′-yl)-3-(1-methy1-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-{(3R)-4-[(cis-3-methoxycyclobutyl)carbonyl]-3-methylpiperazin-1-yl}-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-{(3R)-4-[(3,3-difluorocyclobutyl)carbonyl]-3-methylpiperazin-1-yl}-3-(1-methy1-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[(3R)-4-{[(1S,2S)-2-fluorocyclopropyl]carbonyl}-3-methylpiperazin-1-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[(3R)-3-methyl-4-propanoylpiperazin-1-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-{(3R)-3-methyl-4-[(1-methylcyclopropyl)carbonyl]piperazin-1-yl}-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

3-(1-methyl-1H-pyrazol-4-yl)-5-[(3R)-3-methyl-4-(pyrrolidin-1-ylcarbonyl)piperazin-1-yl]pyrazine-2-carbonitrile;

5-[(3R)-3-methyl-4-(2-oxa-6-azaspiro[3.3]hept-6-ylcarbonyl)piperazin-1-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

(2R)-4-[5-cyano-6-(1-methyl-1H-pyrazol-4-yl)pyrazin-2-yl]-N-(cyclopropylmethyl)-2-methylpiperazine- 1-carboxamide;

5-[(3R)-4-{[(3S)-3-methoxypyrrolidin-1-yl]carbonyl}-3-methylpiperazin-1-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-{(3R)-4-[(3-methoxyazetidin-1-yl)carbonyl]-3-methylpiperazin-1-yl}3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

5-[(3R)-4-(azetidin-1-ylcarbonyl)-3-methylpiperazin-1-yl]-3-(1-methyl-1H-pyrazol-4-yl)pyrazine-2-carbonitrile;

methyl (2R)-4-[5-cyano-6-(1-methyl-1H-pyrazol-4-yl)pyrazin-2-yl]-2-methylpiperazine-1-carboxylate; or

5-[(3R)-3-methyl-4-{[(1R,2R)-2-methylcyclopropyl]carbonyl}piperazin-1-yl]-3-(1H-pyrazol-4-yl) pyrazine-2-carbonitrile.

11. A pharmaceutical composition comprising an effective amount of a compound according to claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

12. The pharmaceutical composition according to claim 11 , further comprising one or more other therapeutic agents.

13. A method for the inhibition of PI3K-delta comprising administering to a patient an amount of a compound of claim 1 or a pharmaceutically acceptable salt or a stereoisomer thereof effective to inhibit PI3K-delta.