反应详情

First 2.8 g of hydrazine hydrate and, 30 minutes later, 12.8 g of acetone are added dropwise to a solution of 16 g of ethyl 2-(2,3,4,5-tetrafluorobenzoyl)-3-ethoxyacrylate in 70 ml of ethanol, while cooling with dry ice/acetone at -25° C. to -30° C. The mixture is allowed to come slowly to room temperature and is then stirred at 20° C. to 25° C. for a further hour. The solvent is then distilled off in vacuo and the orange-colored residue is recrystallized from cyclohexane/light petrol. 12.5 g of ethyl 2-(2,3,4,5-tetrafluorobenzoyl)-3-(2-propylidenehydrazino)acrylate of melting point 86° C. are obtained.

1. customto come slowly to room temperature
2. distillationThe solvent is then distilled off in vacuo
3. customthe orange-colored residue is recrystallized from cyclohexane/light petrol