Patent ID: 8394797

Claim:
A method of treating pain, comprising administering to a patient a therapeutically effective amount of a compound of formula I: wherein R 1 is selected from the group formed by hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, and substituted or unsubstituted heterocyclylalkyl; R 2 is selected from the group formed by hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted arylalkyl, and substituted or unsubstituted heterocyclylalkyl; R 3 and R 4 are independently selected from the group formed by hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl and substituted or unsubstituted heterocyclylalkyl or, together, R 3 and R 4 form a 3 to 6 substituted or unsubstituted member ring; R 5 and R 6 are independently selected from the group formed by hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl and substituted or unsubstituted heterocyclylalkyl or, R 5 and R 6 together, form a substituted or unsubstituted heterocyclyl having 3 to 7 atoms in the ring; n is selected from 0, 1 and 2; m is selected from 0, 1, 2, 3, 4; the dotted line ------ is either a single or a double bond; with the proviso that when R 1 is phenyl, R 2 is H, the dotted line ------ is a double bond, m is 1, and R 5 and R 6 form a 2,5-dioxopyrrolidine or a 5-ethoxy-2-oxo-pyrrolidine, then R 3 and R 4 are not both at the same time H or methyl; or a pharmaceutically acceptable salt, stereoisomer, ester, phosphate ester, metal salts sulfonate ester, carbamate, or amide thereof.