Patent ID: 8778958

Claim:
A compound of formula (I): or a pharmaceutically acceptable salt thereof, wherein R 1 is selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cyclo alkyl, optionally substituted (CH 2 ) 1-5 -cycloalkyl, optionally substituted cycloalkenyl, optionally substituted aryl, and optionally substituted heteroaryl; R 2 is selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted optionally substituted alkynyl, and optionally substituted akanoyl; R 3 is selected from the group consisting of hydrogen, OH, and optionally substituted alkoxy; R 4 is selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted aryl, and optionally substituted heteroaryl; L is a group linking N 2 and R 5 and represents C═O; R 5 is substituted aryl, wherein aryl is substituted with one or more alkyl, alkenyl, haloalkyl, hydroxyalkyl, heteroaryl, heterocycle, cycloalkyl, acylamino, trifluoromethyl, trifluoromethoxy, keto, thioxo, alkylthio, alkylsulfinyl, alkylsulfonyl, and cyano; R 6 is selected from the group consisting of hydrogen, or R 6 is absent; N 1 is a nitrogen atom, which is neutral when R 6 is absent, or is charged when R 6 is present, to satisfy the normal valence of a tertiary or quaternary nitrogen; N 2 is a nitrogen atom, which is bound to the opiate nucleus in α or β stereochemistry or a mixture thereof; and C x and C y together form an alkylidene group (—CH 2 CH 2 —) or alkenylidene group (—CH═CH—); any of the attached hydrogens may be replaced to form a substituted alkenylidene group or substituted alkylidene of any possible stereochemistry.