反应详情

Compound XII (1.50 g, 2.4 mmoles) is dissolved in ethanol (10 ml) and hydrazine hydrate (1.16 ml, 24 mmoles) is added. The mixture is allowed to stand at room temperature for 24 hours and then evaporated in vacuo. The resulting solid residue is dissolved in water-saturated ethyl acetate and the solution is washed with water two times and quickly dried over magnesium sulfate. The crystalline precipitates which separated upon standing at room temperature are filtered off, washed with ether and dried in vacuo. Recrystallization from ethyl acetate-ether affords the hydrazide XIII in pure form; yield 1.41 g (94%), mp. 121°-123° C, [α]D22.5 - 8.5°±0.5° (c 1.0, dimethylformamide), -18.2°±0.6° (c 1.0, methanol).

1. customevaporated in vacuo
2. dissolutionThe resulting solid residue is dissolved in water-saturated ethyl acetate
3. washthe solution is washed with water two times
4. dry with materialquickly dried over magnesium sulfate
5. customThe crystalline precipitates which
6. customseparated
7. customupon standing at room temperature
8. filtrationare filtered off
9. washwashed with ether
10. customdried in vacuo
11. customRecrystallization from ethyl acetate-ether