反应详情

The keto-enol compound (7.28 g, 26.5 mmol) prepared in Example 63 was refluxed for 12 hours with N,N-dimethylformamide dimethylacetal (24 mL, 204 mmol). Excess N,N-dimethylformamide dimethylacetal was removed by vacuum distillation, and the reaction mixture was dissolved in anhydrous ethanol (150 mL). To this solution was dropwise added hydrazine hydrate (2.65 g, 53 mmol), and stirred at room temperature for 4 hours. The solvent was removed by vacuum distillation. The concentrate was purified through column chromatography (silica gel, ethyl acetate-hexane, 1:2, v/v) to afford the title compound as a red liquid (4.92 g, 62%).

1. customExcess N,N-dimethylformamide dimethylacetal was removed by vacuum distillation
2. dissolutionthe reaction mixture was dissolved in anhydrous ethanol (150 mL)
3. customThe solvent was removed by vacuum distillation
4. customThe concentrate was purified through column chromatography (silica gel, ethyl acetate-hexane, 1:2