反应详情

To a mixture of 65.2 ml of n-butyllithium (1.61M in hexane) and 100 ml of anhydrous ether was added dropwise 29.3 g of 4-bromo-3,5-dichlorobenzo-trifluoride (3) in 30 ml of anhydrous ether at -78° C., followed by stirring for 20 minutes. Subsequently, 13.3 ml of diethyl carbonate in 50 ml of anhydrous ether was added dropwise to the mixture, followed by stirring at -78° C. for 30 minutes and then at 0° C. for 30 minutes. Ice water was added to the reaction mixture, the mixture was extracted with ether, and the combined ethereal layer was washed with brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting residue was distilled under reduced pressure, giving 18.3 g of the desired product in the form of a colorless oil (yield 63.8%).

1. stirringby stirring at -78° C. for 30 minutes
2. waitat 0° C. for 30 minutes
3. extractionthe mixture was extracted with ether
4. washthe combined ethereal layer was washed with brine
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. distillationThe resulting residue was distilled under reduced pressure