Patent ID: 7592357

Claim:
A compound of formula (I) or a pharmaceutically acceptable salt thereof wherein: R 1 and R 2 , are, independently selected from the group consisting of hydrogen and C 1 -C 6 alkyl; R 3 is selected from the group consisting of phenyl optionally substituted with 1 to 3 substituents selected from the group consisting of F, Cl, trifluoromethyl, and phenyl; naphthyl; and quinolinyl; R 4 is selected from the group consisting of hydrogen and methyl; R 5 is C 1 -C 3 alkyl; R 6 is selected from the group consisting of chlorine, fluorine and hydrogen; and R 7 and R 8 , are, independently selected from the group consisting of hydrogen, halogen, and C 1 -C 3 alkyl.