反应详情

A one-liter reaction flask equipped with a mechanical stirrer, air-cooled condenser, thermometer and dropping funnel was charged with 290 ml of acetic acid and 167.3 g (0.68 mole) of 3'-trifluoromethylacetoacetanilide. Only a portion of the latter dissolved. The dropping funnel contained 108.8 g (0.68 mole) of bromine, a crystal of iodine and 65 ml of acetic acid. The pot mixture was stirred as the bromine solution was added dropwise while maintaining the reaction temperature at 20°-25°. The reaction solids appeared to dissolve and reprecipitate as the bromine addition was continued. When about 65% of the bromine solution had been added, a clear reaction solution was obtained. All material remained in solution when the remaining quantity of bromine solution was added. The reaction solution was allowed to stir overnight at ambient temperature. On the following morning, the solidified mass was added to 2.8 liters of cold water and stirred. The white solid was collected on a vacuum filter and the filter cake was washed with an additional one liter of water. After drying, there was obtained 210 g (95%) of 4-bromo-3'-trifluoromethylacetoacetanilide, m.p. 66°-8°. N.M.R. (CDCl3) ##STR3## 5.3 (CH, enol), 7.2-7.8 (aromatic), 9.0 (HNC=O).

1. customA one-liter reaction flask
2. customequipped with a mechanical stirrer
3. temperatureair-cooled condenser
4. additionwas added dropwise
5. temperaturewhile maintaining the reaction temperature at 20°-25°
6. customThe reaction solids
7. dissolutionto dissolve
8. customa clear reaction solution was obtained
9. additionwas added
10. stirringstirred
11. customThe white solid was collected on a vacuum
12. filtrationfilter
13. washthe filter cake was washed with an additional one liter of water
14. customAfter drying