Patent ID: 7589090

Claim:
A compound of formula (I): or a pharmaceutically acceptable salt thereof, wherein: R 1 is: C 1-6 alkoxy; hydroxy; or halo; R 2 is: C 1-6 alkoxy; halo; C 1-6 alkynyl C 1-6 alkylsulfonyl; or aminosulfonyl; R 3 is: hydrogen; or C 1-6 alkyl; and R 4 is: C 1-6 alkyl; C 3-6 cycloalkyl; C 1-6 alkoxy-C 1-6 alkyl; C 3-6 cycloalkyl-C 1-6 alkyl; hydroxy-C 1-6 alkyl; heterocyclyl; heterocyclyl-C 1-6 alkyl; or R 3 and R 4 together with the nitrogen to which they are attached may form a five or six membered heterocyclyl that optionally includes an additional heteroatom selected from O, N and S.