反应详情

To a solution of S-benzyl-L-cysteinyl-L-prolyl-L-leucyl-glycinamide (0.502 g.) in ethyl acetate (3 ml.) benzyloxycarbonyl-L-asparagine p-nitrophenyl ester (0.387 g., 1.0 mmol) was added and the suspension stirred at room temperature for 48 hr. The precipitate which formed was collected by filtration and washed with ethyl acetate (20 ml.) and ethanol (5 ml.), and then dried. The crude benzyloxycarbonyl-L-asparaginyl-S-benzyl-L-cysteinyl-L-prolyl-L-leucyl-glycinamide was recrystallized from 40% methanol. Yield, 0.718 g. (99%); m.p. 212°- 213.5°; [α]20D -60.5° (c 1, dimethylformamide).

1. customThe precipitate which formed
2. filtrationwas collected by filtration
3. washwashed with ethyl acetate (20 ml.) and ethanol (5 ml.)
4. customdried
5. customThe crude benzyloxycarbonyl-L-asparaginyl-S-benzyl-L-cysteinyl-L-prolyl-L-leucyl-glycinamide was recrystallized from 40% methanol
6. customYield