Patent ID: 6858604

Claim:
A compound of the formula: wherein: R 1 and R 2 are each, independently, hydrogen, alkyl of 1-6 carbon atoms, cycloalkyl of 3 to 7 carbon atoms, —CH 2 -cycloalkyl of 3 to 7 carbon atoms, alkoxy of 1-6 carbon atoms, halogen, fluorinated alkyl of 1 to 6 carbon atoms, —CN, —NH—SO 2 -alkyl of 1-6 carbon atoms, —SO 2 -NH-alkyl of 1-6 carbon atoms, alkyl amide of 1-6 carbon atoms, amino, alkylamino of 1-6 carbon atoms, dialkylamino of 1-6 carbon atoms per alkyl moiety, fluorinated alkoxy of 1-6 carbon atoms, acyl of 2-7 carbon atoms, or phenoyl or thiophenoyl; R 3 and R 4 are each, independently, hydrogen, C 1 -C 6 alkyl or cycloalkyl of 3 to 7 carbon atoms; R 5 is hydrogen or C 1 -C 6 alkyl; R 6 is hydrogen or C 1 -C 6 alkyl; and wherein the dashed line indicates an optional double bond; or a pharmaceutically acceptable salt thereof.