4-HYDROXYPIPERIDINE DERIVATIVES HAVING ANALGESIC ACTIVITY

摘要

A compound represented by the following formula (I): (I) [wherein A represen ts oxygen or a group represented by -NR3- (R3 represents hydrogen or lower alkyl); R1 represents nitro, lower alkoxycarbonyl, carbamoyl optionally substituted by one or two lower alkyls, optionally protected hydroxy, optionally protected carboxyl, lower alkyl substituted by optionally protect ed hydroxy, or tetrazolyl; and R2 represents hydrogen, cyano, or (lower alkyl)sulfonyl; provided that when A is -NR3- then R1 is neither optionally protected hydroxy nor lower alkyl substituted by optionally protected hydrox y] or a salt thereof; a process for producing the compound; and a medicinal composition containing the compound as the active ingredient.