Dicyclohexylcarbodiimide → BOC-Ala-Gly-OBzl

Participants

Reaction Conditions

Reaction Steps

To a solution of 12.9 g of glycine benzyl ester tosylate in 200 ml acetonitrile cooled to 0° C., was added dropwise triethylamine (5.3 ml), followed by addition of 12 g of N-tert-butyloxycarbonylalanine N-hydroxysuccinimide ester (prepared by reaction of N-tert-butyloxycarbonylalanine with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide). The resulting solution was stirred at 0° C. for one hour and then at room temperature for 18 hours. At the end of reaction, the solvent was distilled off under reduced pressure, the residue was extracted with ethyl acetate, and the extract was washed with 5% acetic acid, water and saturated aqueous solution of sodium chloride in that order, giving 16 g of crude product. Purification of this crude product by silica gel chromatography (chloroform:methanol=40:1) afforded 12.6 g of pure N-tert-butyloxycarbonyl-L-alanyl-glycine benzyl ester.

Provenance & Evidence