Triethylamine → 1-Carbobenzoxy-4-piperidinecarboxylic Acid

Participants

Reaction Conditions

Reaction Steps

Benzyl chloroformate (8.5 g) was added dropwise to a stirred mixture of ethyl piperidine-4-carboxylate (7.85 g), triethylamine (6.95 ml) and methylene chloride (50 ml) which had been cooled to 5° C. The mixture was stirred at ambient temperature for 18 hours. The mixture was partitioned between ethyl acetate and 2N aqueous hydrochloric acid. The organic phase was washed with water and with brine, dried (MgSO4) and evaporated. The residue was dissolved in methanol (100 ml) and 2N aqueous sodium hydroxide (125 ml) was added. The mixture was stirred at ambient temperature for 1 hour. The mixture was concentrated by evaporation and the residue was partitioned between diethyl ether and water. The aqueous phase was acidified to pH3 by the addition of concentrated hydrochloric acid and the mixture was extracted with ethyl acetate. The organic extract was washed with water, dried (MgSO4) and evaporated to give 1-benzyloxycarbonylpiperidine-4-carboxylic acid (10.1 g).

Provenance & Evidence