Patent ID: 7638532

Claim:
A compound of Formula I: any of its stereoisomers or any mixture of its stereoisomers, or a pharmaceutically acceptable salt thereof; wherein R a represents hydrogen or alkyl; which alkyl is optionally substituted with one or more substituents independently selected from the group consisting of: halo, trifluoromethyl, trifluoromethoxy, cyano, hydroxy, amino, nitro, alkoxy, cycloalkoxy, alkyl, cycloalkyl, cycloalkylalkyl, alkenyl and alkynyl; and R b represents an aryl group; which aryl group is optionally substituted with one or more substituents independently selected from the group consisting of: halo, trifluoromethyl, trifluoromethoxy, cyano, nitro, hydroxy, alkoxy, cycloalkoxy, alkoxyalkyl, cycloalkoxyalkyl, methylenedioxy, ethylenedioxy, alkyl, cycloalkyl, cycloalkylalkyl, alkenyl, alkynyl, -NR′R″, —(C═O)NR′R″ or —NR′(C═O)R″; wherein R′ and R″ independent of each other are hydrogen or alkyl.