Patent ID: 7671200

Claim:
A compound having the formula or a pharmaceutically acceptable salt thereof, wherein: R 1 is chosen from alkylaryl and substituted alkylaryl; R 2 is lower alkyl; R 2 ′ is hydrogen; and the stereogenic center to which R 2 and R 2 ′ are attached is of the R configuration; R 3 is substituted aryl; R 4 is substituted alkyl; R 5 is hydrogen; R 6 is hydrogen; R 7 is halo; and R 8 is hydrogen, wherein substituted alkyl, substituted alkylaryl, and substituted aryl, respectively, refer to alkyl, alkylaryl, or aryl wherein one or more hydrogen atoms are replaced with alkyl, halogen, hydroxy, alkoxy, fluoroalkyl, carboxy, carboalkoxy, carboxyalkyl, carboxamido, sulfonamidoalkyl, sulfonamidoaryl, aminocarbonyl, benzyloxycarbonylamino, cyano, nitro, primary-, secondary- and tertiary-amino, aminoaklylene, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylsulfonamido, arylthio, arylsulfinyl, arylsulfonyl, amidino, aryl, heteroaryl, heterocyclyl, phenoxy, benzyloxy, or heteroaryloxy.