Patent ID: 8080556

Claim:
A compound of formula (I) or a pharmaceutically acceptable salt thereof, wherein: R 1 is selected from the group consisting of C 1 -C 6 alkyl, C 1 -C 6 alkyl substituted with 1 to 6 fluorine, C 1 -C 6 alkyl substituted with 1 to 2 chlorine and up to six fluorine, C 3 -C 8 cycloalkyl, and C 3 -C 8 cycloalkyl substituted with 1 to 6 groups selected from fluorine, chlorine and C 1 -C 3 alkyl; R 2 and R 3 are independently selected from the group consisting of chlorine, fluorine, —CN, C 1 -C 3 alkoxyl, C 1 -C 3 alkyl and C 1 -C 3 alkyl substituted with 1 to 6 fluorine; R 4 is selected from the group consisting of hydrogen, fluorine, chlorine, bromine, —CN, C 1 -C 3 alkyl and C 1 -C 3 alkyl substituted with 1 to 6 fluorine; R 5 and R 6 are independently selected from the group consisting of hydrogen, fluorine, chlorine, bromine, —CN, C 1 -C 3 alkyl and C 1 -C 3 alkyl substituted with 1 to 6 fluorine; provided that (1) when R 4 , R 5 and R 6 are all hydrogen, then R 2 and R 3 are not both chlorine; and (2) the compound of formula I is not any of the following compounds,