Triethylamine → methyl 4-[N-(cyclopropylcarbonyl)-N-phenylamino]-1-(2-phenylethyl)-4-piperidinecarboxylate hydrochloride

Participants

Reaction Steps

A mixture of 5.1 parts of methyl 4-(phenylamino)-1-(2-phenylethyl)-4-piperidinecarboxylate, 1.9 parts of cyclopropanecarbonyl chloride, 2.7 parts of N,N-diethylethanamine and 67.5 parts of methylbenzene is stirred and refluxed overnight. The reaction mixture is cooled to room temperature and poured onto water. The product is extracted with methylbenzene. The extract is washed with water, dried, filtered and evaporated. The oily residue is purified by column-chromatography over silica-gel using a mixture of trichloromethane and 3% of methanol as eluent. The pure fractions are collected and the eluent is evaporated. The oily residue is converted into the hydrochloride salt in 2,2'-oxybispropane and 2-propanol. The salt is filtered off and crystallized from 4-methyl-2-pentanone, yielding methyl 4-[N-(cyclopropylcarbonyl)-N-phenylamino]-1-(2-phenylethyl)-4-piperidinecarboxylate hydrochloride; mp. 197.8° C.

Provenance & Evidence