4-Methylmorpholine → H-Gly-Asp(OBzl)-Val-OBzl

Participants

Reaction Conditions

Reaction Steps

A solution of 4.2 g. of H-Asp(OBzl)-Val-OBzl.TFA in 50 ml of ethyl acetate is treated in succession with 2.72 g of Boc-Gly-OSu and 0.88 ml of N-methylmorpholine and then stirred at 20° C. for 72 hours. The reaction mixture is partitioned between ethyl acetate and water and the organic phase is washed with 5% KHSO4 /10% K2SO4 solution, water, saturated NaHCO3 solution, water and saturated NaCl solution. After drying the solution is concentrated. The residue is dissolved in 30 ml of trifluoroacetic acid held at 20° C. for 20 minutes and then concentrated. After crystallization from ethyl acetate/hexane there are obtained 3.5 g of H-Gly-Asp(OBzl)-Val-OBzl, TFA (1:1), m.p. 150°-151° C.

Provenance & Evidence