Hydrochloric Acid → 1-(3-Methylphenyl)-2-[1-(phenylmethyl)-4-piperidinyl]ethanone hydrochloride

Participants

Reaction Steps

To a stirred and refluxing Grignard-complex, previously prepared starting from 3.65 parts of magnesium, 26 parts of 1-bromo-3-methylbenzene and 70 parts of 1,1'-oxybisethane, is added dropwise a solution of 21.4 parts of 1-(phenylmethyl)-4-piperidineacetonitrile in 70 parts of 1,1'-oxybisethane. Upon completion, stirring is continued for 4 hours at reflux temperature. The reaction mixture is cooled in and ice-bath and decomposed by the addition of a saturated ammonium chloride solution. The layers are separated and the aqueous phase is extracted twice with 1,1'-oxybisethane. The combined organic phases are dried, filtered and evaporated. The oily residue is purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (95:5 by volume) as eluent. The pure fractions are collected and the eluent is evaporated. The oily residue is stirred in 2,2'-oxybispropane with activated charcoal. The latter is filtered off till a clear filtrate is obtained. The filtrate is acidified with 2 -propanol saturated with hydrogen chloride. The whole is evaporated and the residue is crystallized from warm 4-methyl-2-pentanone, yielding 24.5 parts (71%) of 1-(3-methylphenyl)-2-[1-(phenylmethyl)-4-piperidinyl]ethanone hydrochloride; mp. 165.8° C.

Provenance & Evidence