Dicyclohexylcarbodiimide → N-(1-Carboxyethyl)-L-alanyl-L-proline

Participants

Reaction Steps

Dissolve 0.75 g of N-(1-carbobenzoxyethyl)-L-alanine in pyridine and add 7.5 ml of 1 M triethylamine in pyridine. Cool, and add 1.09 g L-proline benzyl ester hydrochloride and 0.678 g dicyclohexylcarbodiimide. Store at 0° C. for 20 hours. Filter, then concentrate the reaction mixture in vacuo. Dissolve the residue in ethyl acetate and wash this solution with saturated K2CO3, then brine. Dry the organic phase, concentrate in vacuo, then chromatograph the residue on silica gel with ethyl acetate-hexane to isolate the diastereoisomeric mixture of N-(1-carbobenzoxyethyl)-L-alanyl-L-proline.

Provenance & Evidence