120656-93-1 A 3665.HCl N-(1-(2-(4-Ethyl-5-oxo-delta(sup 2)-tetrazolin-1-yl)ethyl)-4-phenyl-4-piperidyl)-2'-fluoropropionanilide monohydrochloride Propanamide, N-(1-(2-(4-ethyl- 4,5-dihydro-5-oxo-1H-tetrazol-1-yl)ethyl)-4-phenyl-4-piperidinyl)-N-(2-fluorophenyl)-, monohydrochloride Propanamide, N-(1-(2-(4-ethyl-4,5-dihydro-5-oxo-1H-tetrazol-1-yl)ethyl)-4-phenyl-4-piperidinyl)-N-(2-fluorophenyl)-, monohydrochloride TREFENTANIL HYDROCHLORIDE Trefentanil Trefentanil hydrochloride [USAN]