3-Methoxyphenyl isocyanate → tert-butyl (2RS,5SR)-1-{2-[3-(3-methoxyphenyl)ureido]acetyl}-5-phenylprolinate

Participants

Reaction Conditions

Reaction Steps

0.9 cm3 of 3-methoxyphenyl isocyanate is added to a solution of 2 g of tert-butyl (2RS,5SR)-1-(2-aminoacetyl)-5-phenylprolinate in 20 cm3 of anhydrous tetrahydrofuran. The reaction mixture is stirred for 20 hours at a temperature in the vicinity of 25° C. After evaporation of the solvent under reduced pressure at a temperature in the vicinity of 45° C., the crude product obtained is purified by chromatography on silica [eluent: dichloromethane/methanol (95/5 by volume)]. The fractions containing the expected product are combined, then concentrated to dryness under reduced pressure. After recrystallization in acetonitrile, 1.9 g of tert-butyl (2RS,5SR)-1-{2-[3-(3-methoxyphenyl)ureido]acetyl}-5-phenylprolinate melting at 174° C., are obtained.

Provenance & Evidence