Patent ID: 7879825

Claim:
A method for treating pain in a mammal comprising administering to a mammal a therapeutically effective amount of at least one compound of formula (I) or a pharmaceutically acceptable salt thereof: wherein: R 1 is hydrogen, a C 1 to C 6 alkyl group, a C 2 to C 7 acyl group, a C 1 to C 6 alkanesulfonyl group, or a C 6 to C 14 aroyl group; A is alkylene of 1 to 4 carbon atoms or alkenylene of 2 to 4 carbon atoms; R 2 and R 3 are independently selected from hydrogen, or with the proviso that at least one of R 2 and R 3 is not hydrogen; R 4 and R 5 are independently selected from hydrogen, a C 1 to C 4 alkyl group, a C 5 to C 7 aryl group, a C 6 to C 15 alkylaryl group having 5 to 7 carbon atoms in the aryl ring, a C 2 to C 7 alkenyl group, or C 2 to C 7 alkynyl group, or R 4 and R 5 may together form a spiro C 3 to C 8 carbocyclic ring; R 6 is a C 1 to C 12 linear or branched alkyl group, a C 2 to C 7 linear or branched alkenyl or alkynyl group, a C 5 to C 13 aryl group, a C 6 to C 21 alkylaryl group having 5 to 13 carbon atoms in the aryl moiety; a 5 to 13 membered heteroaryl group, a 6 to 21 membered alkylheteroaryl group having 5 to 13 members in the heteroaryl moiety, a C 4 to C 8 cycloalkyl group, a C 5 to C 16 alkylcycloalkyl group having 4 to 8 carbon atoms in the cycloalkyl ring; R 7 and R 8 are independently selected from hydrogen, a C 1 to C 12 linear or branched alkyl group, a C 2 to C 7 linear or branched alkenyl or alkynyl group, a C 5 to C 13 aryl group, a C 6 to C 21 alkylaryl group having 5 to 13 carbon atoms in the aryl moiety, a 5 to 13 membered heteroaryl group, a 6 to 21 membered alkylheteroaryl group having 5 to 13 members in the heteroaryl moiety, or R 7 and R 8 may together form a cycloalkyl or heterocycloalkyl group having in the ring 4 to 8 carbon atoms and optionally one to two atoms selected from nitrogen, oxygen or sulfur; wherein any R 1 to R 8 group having an aryl, heteroaryl, cycloalkyl or heterocycloalkyl moiety may optionally be substituted on the aryl, heteroaryl, cycloalkyl or heterocycloalkyl moiety with 1 to about 5 substituents independently selected from a halogen atom, a cyano, nitro or hydroxyl group, a C 1 -C 6 alkyl group, or a C 1 -C 6 alkoxy group.