4-Piperidinecarboxylic acid, 3-methyl-4-((1-oxopropyl)phenylamino)-1-(2-phenyleethyl)-, methyl ester, (3R,4S)-rel-(-)- 4-Piperidinecarboxylic acid, 3-methyl-4-((1-oxopropyl)phenylamino)-1-(2-phenylethyl)-, methyl ester, cis-(-)- 61380-40-3 Lofentanil Lofentanila [INN-Spanish] Lofentanilum [INN-Latin] Methyl cis-(-)-3-methyl-4-((1-oxopropyl)phenylamino)-1-(2-phenylethyl)-4-piperidinecarboxylate