Patent ID: 8168668

Claim:
A compound having the formula: wherein: R 1 is selected from nitro, cyano, halo, and acetyl; R 2 is selected from phenyl, heteroaryl, phenylmethyl, and phenyloxymethyl; where R 2 is optionally substituted with one or more substituents Q selected from C 1-6 alkyl, C 1-6 alkoxy, C 1-6 haloalkyl, halo, C 1-6 haloalkoxy, C 3-7 cycloalkoxy, C 3-7 cycloalkyl, C 1-6 alkynyl, C 3-7 cycloalkylalkoxy, C 3-7 heterocycloalkyloxy, and C 1-3 alkoxyC 1-6 alkoxy, said substituent(s) Q being attached to the aromatic and/or heteroaromatic ring(s) of R 2 ; R 3 is H or F; R 4 is methyl, methoxycarbonyl or ethyl; or R 2 and R 4 may together form a monocyclic or bicyclic ring system; and salts thereof.