反应详情

温度

-10 °C

A solution of benzyloxycarbonylglycyl-glycine (13.31 g, 50 mmoles), N-hydroxysuccinimide (5.75 g) and N, N'-dicyclohexylcarbodiimide (11.3 g) in dimethylformamide (180 ml) is stirred and cooled (-10° C.) for 1 hour. A precooled (-10° C.) solution of serine methyl ester, liberated from its hydrochloride (7.8 g, 50 mmoles) with N-ethylpiperidine (6.85 ml), in the same solvent (50 ml) is added, and the reaction mixture is stirred for 3 hours at 0° C. and allowed to stand for 8 hours at room temperature; the N, N'-dicyclohexylurea precipitate is filtered off and the filtrate is admixed with 100% hydrazine hydrate (15 ml). After 3 days of standing at room temperature, the formed hydrazide is separated, washed with ethanol and crystallized from aqueous ethanol. Yield 15.2 g (83%), m.p. 172-175 (unchanged after recrystallization). Composition: C15H21N5O6.

1. additionis added
2. waitto stand for 8 hours at room temperature
3. filtrationthe N, N'-dicyclohexylurea precipitate is filtered off
4. waitAfter 3 days of standing at room temperature
5. customthe formed hydrazide is separated
6. washwashed with ethanol
7. customcrystallized from aqueous ethanol
8. customYield 15.2 g (83%), m.p. 172-175 (unchanged after recrystallization)