PHENYLPIPERIDINE DERIVATIVES

摘要

A phenylpiperidine derivative or pharmaceutical acceptable salt thereof represented by formula (I): <CHEM> wherein X represents CH or N; Y-Z represents CH2-O, CH2-S, CH2-CH2, CH=CH or CONR<5> (wherein R<5> represents hydrogen or lower alkyl); R<1> represents hydrogen, lower alkyl, halogen, lower alkoxy or trifluoromethyl; and R<2>, R<3> and R<4> are the same or different and each represents hydrogen, lower alkyl or QR<6> (wherein Q represents a single bond or lower alkylene, and R<6> represents hydroxy, lower alkoxyalkoxy, lower alkoxy, lower alkylthio, nitro, halogen, lower alkanoyloxy, lower alkoxycarbonyl, lower alkanoyl or carboxyl). The present invention provides novel phenylpiperidine derivatives useful as analgesics.