Patent ID: 7368477

Claim:
A compound of formula I: or pharmaceutically acceptable salts thereof, wherein: each of R 1 and R 1′ is independently hydrogen, methyl, ethyl, 2-fluoroethyl, 2,2-difluoroethyl or cyclopropyl; each of R 2 , R 3 and R 4 is independently hydrogen, halogen, OH, lower alkyl, lower alkoxy, trifluoromethyl, trifluoromethoxy, or CN; Ar is thienyl, furyl, pyridyl, or phenyl wherein Ar is optionally substituted with one or more R x groups; each R x is independently halogen, —OH, —CN, lower alkyl, lower alkoxy, —CF 3 , or —OCF 3 ; and n is one or two.