4-Methylmorpholine → Z-Gly-Phe-Leu-OBut

Participants

Reaction Conditions

Reaction Steps

Z-Gly-OH (25.2 g., 132 mM) was dissolved in DMF (300 ml.) and the solution was cooled to -10° C. N-methylmorpholine (14.8 ml., 132 mM) was added, followed by ethyl chloroformate (12.1 ml., 126 mM). After 3 minutes at -10° C., a solution of H-Phe-Leu-OBut (40.1 g., 120 mM) in DMF (100 ml.) was added, and the mixture was stirred at 0° C. overnight. The solvent was evaporated and the residue was dissolved in ethyl acetate (600 ml.) and washed successively with water (2×60 ml.), 2 N-aqueous potassium bicarbonate (3×60 ml.), and water (3×60 ml.). The solution was dried (MgSO4) and filtered. The solvent was evaporated to give Z-Gly-Phe-Leu-OBut.

Provenance & Evidence