Patent ID: 7291632

Claim:
A compound of formula I: or a pharmaceutically acceptable acid addition salt thereof, where; X is —C(R 3c )═ or —N═; R 1 is C 2 –C 6 alkyl, substituted C 2 –C 6 alkyl, C 3 –C 7 cycloalkyl, substituted C 3 –C 7 cycloalkyl, phenyl, substituted phenyl, heterocycle, or substituted heterocycle; R 2 is hydrogen, C 1 –C 3 n-alkyl, C 3 –C 6 cycloalkyl-C 1 –C 3 alkyl, or a group of formula II provided that when R 1 is C 2 –C 6 alkyl or substituted C 2 –C 6 alkyl, R 2 is hydrogen or methyl; R 3a , R 3b , and, when X is —C(R 3c )═, R 3c , are each independently hydrogen, fluoro, or methyl, provided that no more than one of R 3a , R 3b , and R 3c may be other than hydrogen; R 4 is hydrogen or C 1 –C 3 alkyl; R 5 is hydrogen, C 1 –C 3 alkyl, or C 3 –C 6 cycloalkylcarbonyl, provided that when R 3a is other than hydrogen, R 5 is hydrogen; R 6 is hydrogen or C 1 –C 6 alkyl; and n is an integer from 1 to 6 inclusively.