Patent ID: 7619096

Claim:
A compound of formula (I): wherein R 1 is n-propyl, 1-methylethyl, 2-methylpropyl, or 3,3-dimethylpropyl; R 2 , R 3 and R 4 are each independently selected from hydrogen or C 1 -C 2 alkyl; and Ar 1 is a phenyl group which is optionally substituted with 1, 2 or 3 substituents each independently selected from halo, trifluoromethyl and C 1 -C 4 alkyl and/or with 1 substituent selected from phenyl, phenyl substituted with 1, 2 or 3 halo substituents, pyridinyl, pyrazolyl, phenoxy and phenoxy substituted with 1, 2 or 3 halo substituents; pyridinyl; or pyridinyl substituted with 1, 2 or 3 substituents each independently selected from halo, trifluoromethyl and C 1 -C 4 alkyl and/or with 1 substituent selected from phenyl and phenyl substituted with 1, 2 or 3 halo substituents; or a pharmaceutically acceptable salt thereof.