Patent ID: 7645764

Claim:
A compound of the formula: or a pharmaceutically acceptable salt thereof, wherein: R 1 is: C 1-6 alkyl; halo; C 1-6 alkoxy; halo-C 1-6 alkyl; or hetero-C 1-6 alkyl; R 2 is: cyano; an optionally substituted five membered monocyclic heteroaryl; —C(O)—OR a ; —C(O)—NR b R c ; or —C(O)—NR d —NR e —R f ; wherein R a , R b , R d and R e each independently is; hydrogen; or C 1-6 alkyl; and R c and R f each independently is: hydrogen; C 1-6 alkyl; halo-C 1-6 alkyl; C 1-6 alkoxy; hetero-C 1-6 alkyl; C 3-6 cycloalkyl; C 3-6 cycloalkyl-C 1-6 alkyl; aryl; aryl-C 1-6 alkyl; heteroaryl; or heteroaryl-C 1-6 alkyl; C 1-6 alkyl-carbonyl; halo-C 1-6 alkyl-carbonyl; aryl-carbonyl; aryl-C 1-6 alkyl-carbonyl; heteroaryl-carbonyl; or heteroaryl-C 1-6 alkyl-carbonyl. R 3 is: C 1-6 alkyl; C 3-6 cycloalkyl; C 3-6 cycloalkyl-C 1-6 alkyl; or hetero-C 1-6 alkyl; and R 4 is: hetero-C 1-6 alkyl; or heterocyclyl.