N-Ethylpiperidine → Benzyloxycarbonylglutaminyl-glycyl-glycine methyl ester

Participants

Reaction Steps

A suspension of glycyl-glycine methyl ester hydrochloride (1.9 g; 10 mmoles) in a dimethylformamide-dichloromethane (1:2) mixture (30 ml) is admixed with N-ethylpiperidine (1.4 ml) and stirred for 2 hours at room temperature. After that benzyloxycarbonylglutamine pentachlorphenyl ester (5.3 g; 10 mmoles) is added and the reaction mixture is stirred at room temperature a further 4 hours. After 8 hours of standing, the precipitated crystalline product is separated and crystallized from methanol - dichloromethane. Yield 2.5 g (61%), m.p. 129°-134° C., after additional crystallization from methanol 132°-134° C. Rf 0.57/S1, 0.78/S2⟦alpha⟧sub.D20 -8.5° (c 0.2; 50% acetic acid). Composition: C18H24N4O7.1/2H2O.

Provenance & Evidence