Dicyclohexylcarbodiimide → HCID 53875478, compound

Participants

Reaction Steps

To a stirred mixture consisting of 4.82 g. of N-benzyloxycarbonyl-L-seryl-L-tyrosine, 1.519 g. of N-hydroxysuccinimide, 1.675 g. of glycine ethyl ester hydrochloride, and 60 ml. of N,N-dimethylformamide, cooled to -15° C., is added first 1.68 ml. of triethylamine and then 2.48 g. of dicyclohexylcarbodiimide, and the resulting mixture is stirred at -15° C. for 2 hours and at room temperature for 25 hours. The mixture is then concentrated to remove solvent, and the residue is partitioned between dilute hydrochloric acid and ethyl acetate. The organic layer is separated, washed with saturated aqueous sodium chloride, with saturated aqueous sodium bicarbonate, and with saturated aqueous sodium chloride again, dried, and evaporated to give a solid residue of N-benzyloxycarbonyl-L-seryl-L-tyrosylglycine ethyl ester; m.p. 166°-169° C., following crystallization from ethyl acetate; [α]D25 -23.2° (2% in methanol).

Provenance & Evidence