(-)-Methyl cis-3-methyl-1-phenethyl-4-(N-phenylpropionamido)isonipecotate oxalate (1:1) 4-Piperidinecarboxylic acid, 3-methyl-4-((1-oxopropyl)phenylamino)-1-(2-phenylethyl)-, methyl ester, cis, (-)-, ethanedioate (1:1) 61380-41-4 EINECS 262-750-7 Lofentanil oxalate Lofentanil oxalate [USAN] R 34,995 R 34995 cis-(-)-4-(Methoxycarbonyl)-3-methyl-1-phenethyl-4-(N-phenylpropionylamino)piperidinium hydrogen oxalate