Chloroform → Ethyl N-(1-((benzyloxy)carbonyl)-L-prolyl)-L-leucinate

Participants

Reaction Steps

N-Benzyloxycarbonyl-L-proline (1.25 g) and L-leucine ethyl ester hydrochloride (1.0 g) are suspended into chloroform (10 ml), and therein is dissolved triethylamine (1.40 ml). To the solution is added ethyl 2-methanesulfonyloxyimino-2-cyanoacetate (1.1 g) and the mixture is stirred at room temperature for 16 hours. After reaction, the reaction mixture is extracted with ethyl acetate. The extract is washed with water, 1 N aqueous sodium hydrogen carbonate, water, 1 N hydrochloric acid and water in order and then dried over anhydrous magnesium sulfate. After drying, the solvent is distilled off and the resulting residue is crystallized from petroleum ether to give N-(N-benzyloxycarbonyl-L-prolyl)-L-leucine ethyl ester (0.8 g), melting point: 65°-67° C.

Provenance & Evidence