Aminopyridine derivatives as TAM family kinase inhibitors

1. A compound represented by Formula (IA4):

wherein R 1 is phenyl or phenyl substituted by one or more substituents selected from the group consisting of alkyl and halo, benzyl, or cycloalkylmethyl;

R 2 is piperidinyl or piperidinyl substituted by one or more substituents selected from the group consisting of alkyl, —C(O)R 14 and t-butyl carboxylate, wherein R 14 is hydrogen, alkyl, phenyl, benzyl and cycloalkyl; and

each of R 3 and R 4 is hydrogen.

2. The compound of claim 1 wherein:

R 1 is phenyl or phenyl substituted by one or more substituents selected from the group consisting of alkyl and halo; and

R 2 is piperidinyl or piperidinyl substituted by one or more substituents selected from the group consisting of alkyl, —C(O)R 14 and t-butyl carboxylate, wherein R 14 is alkyl, phenyl, or cyclopropyl.

3. The compound of claim 2 being:

tert-butyl 4-(4-(6-amino-5-(5-phenyl-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidine-1-carboxylate;

3-(5-phenyl-1,3,4-oxadiazol-2-yl)-5-(1-(piperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine;

3-(5-(2,6-dichloro-3-fluorophenyl)-1,3,4-oxadiazol-2-yl)-5-(1-(piperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine;

3-(5-(4-(tert-butyl)phenyl)-1,3,4-oxadiazol-2-yl)-5-(1-(piperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine;

tert-butyl 4-(4-(6-amino-5-(5-(4-(tert-butyl)phenyl)-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidine-1-carboxylate;

3-(5-(2,5-difluorophenyl)-1,3,4-oxadiazol-2-yl)-5-(1-(piperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine;

3-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)-5-(1-(piperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine;

tert-butyl 4-(4-(6-amino-5-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidine-1-carboxylate;

3-(5-(4-fluorophenyl)-1,3,4-oxadiazol-2-yl)-5-(1-(piperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine;

tert-butyl 4-(4-(6-amino-5-(5-(4-fluorophenyl)-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidine-1-carboxylate;

1-(4-(4-(6-amino-5-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidin-1-yl)ethanone;

3-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)-5-(1-(1-methylpiperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine;

1-(4-(4-(6-amino-5-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidin-1-yl)-4-methylpentan-1-one;

(4-(4-(6-amino-5-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidin-1-yl)(cyclopropyl)methanone;

(4-(4-(6-amino-5-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidin-1-yl)(phenyl)methanone;

1-(4-(4-(6-amino-5-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidin-1-yl)-2-phenylethanone;

3-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)-5-(1-(1-ethylpiperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine; or

3-(5-(2,6-dichlorophenyl)-1,3,4-oxadiazol-2-yl)-5-(1-(1-dodecylpiperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine.

4. The compound of claim 1 wherein:

R 1 is cyclopropylmethyl or benzyl; and

R 2 is piperidinyl.

5. The compound of claim 4 being:

tert-butyl 4-(4-(6-amino-5-(5-(cyclopropylmethyl)-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidine-1-carboxylate;

3-(5-(cyclopropylmethyl)-1,3,4-oxadiazol-2-yl)-5-(1-(piperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine;

tert-butyl 4-(4-(6-amino-5-(5-benzyl-1,3,4-oxadiazol-2-yl)pyridin-3-yl)-1H-pyrazol-1-yl)piperidine-1-carboxylate; or

3-(5-benzyl-1,3,4-oxadiazol-2-yl)-5-(1-(piperidin-4-yl)-1H-pyrazol-4-yl)pyridin-2-amine.

6. A pharmaceutical composition comprising a compound of claim 1 and a pharmaceutically acceptable excipient.