Ethyl chloroformate → Ethyl 4-(4-fluorobenzoyl)-4-phenylpiperidine-1-carboxylate

Participants

Reaction Steps

To a stirred mixture of 79 parts of (4-fluorophenyl) [4-phenyl-1-(phenylmethyl)-4-piperidinyl]methanone and 630 parts of methylbenzene were added dropwise 32 parts of ethyl carbonochloridate at room temperature. Upon completion, stirring was continued for 5 hours at reflux temperature. The reaction mixture was evaporated and the (chloromethyl)benzene was distilled in vacuo (pump). The oily residue was purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (98:2 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of 2,2'-oxybispropane and a small amount of petroleumether, yielding 35.5 parts of ethyl 4-(4-fluorobenzoyl)-4-phenyl-1-piperidinecarboxylate; mp. 91.7° C. (intermediate 15).

Provenance & Evidence