Benzyl chloroformate → N-Cbz-D-Asparagine

Participants

Reaction Steps

D-Asparagine, 50 g., is dissolved in 500 ml. of water at 60° C., adding 70 g. of sodium bicarbonate and cooling to 20° C. The solution is treated with 68 g. of benzylchloroformate during one hour with stirring and is stirred for an additional two and a half hours. The solution is extracted three times with ether and the aqueous solution is acidified with cold concentrated hydrochloric acid. The white solid product is separated, washed with water and dried; 77 g.; m.p. 165°-166° C.; [α]D23 + 7.4° (c 2.02, DMF).

Provenance & Evidence