Patent ID: 8048907

Claim:
A compound of formula (I), or a pharmaceutically acceptable salt thereof: wherein: R 1 represents unsubstituted methyl, ethyl, C 3-5 cycloalkyl, pyridinylmethyl-, phenyl or benzyl; R 2 and R 3 independently represent hydrogen, halogen, C 1-6 alkyl, arylmethyl-, C 2-6 alkenyl, C 2-6 alkynyl or C 3-6 cycloalkylmethyl-; and any of said C 1-6 alkyl, arylmethyl-, C 2-6 alkenyl, C 2-6 alkynyl or C 3-6 cycloalkylmethyl- is optionally substituted with 1, 2 or 3 halogen atoms; R 4 , R 5 and R 6 independently represent hydrogen, fluorine or methyl; and R 7 , R 8 , R 9 , R 10 and R 11 independently represent hydrogen, halogen, cyano, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 3-6 cycloalkyl or phenyl, and any of said C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 3-6 cycloalkyl or phenyl is optionally substituted with 1, 2 or 3 halogen atoms; or R 10 and R 11 together with the carbon atoms to which they are attached form a benzene ring which is optionally substituted with 1, 2 or 3 halogen atoms; with the proviso that when R 7 and R 11 are both selected from hydrogen or fluorine, at least one of R 8 , R 9 and R 10 is a halogen atom, or R 8 , R 9 and R 10 are selected from the group consisting of hydrogen and CF 3 and one, but not more than one, of R 8 , R 9 and R 10 is CF 3 .