Dicyclohexylcarbodiimide → Benzyl N-[(1S)-1-(methylcarbamoyl)-2-phenylethyl]carbamate

Participants

Reaction Steps

A mixture of 1.00 g of Cbz-Phe-OH (Sigma Chemical Company), 0.385 g of N-hydroxysuccinimide and 0.541 g of 1,3-dicyclohexylcarbodiimide in 5 mL of dry THF was kept at 4° C. under N2 overnight. The resulting precipitate was removed by filtration, and to the filtrate was added excess 40% aqueous methylamine at room temperature. The mixture was stirred at room temperature for 30 min. The solid was removed by filtration and the filtrate was partitioned between saturated aqueous NaHCO3 and CH2Cl2. The organic layer was separated, dried over anhydrous Na2SO4, and evaporated under reduced pressure to give 1.12 g of the crude Cbz-Phe-NHMe.

Provenance & Evidence