反应详情

Under an argon atmosphere, 1,2-dibromo-1,1,2,2-tetrachloroethane (7.57 g, 23.2 mmol) was dissolved in toluene (12.5 mL), the solution was added with triphenylphosphine (6.1 g, 23.2 mmol) at 0° C., and the mixture was stirred for 30 minutes. The reaction mixture was added dropwise with a solution of (R)-1-[3,5-bis(trifluoromethyl)phenyl]ethanol (5.0 g, 19.4 mmol, >99.5% ee) in toluene (12.5 mL) at 0° C. over 10 minutes or more, and then the mixture was warmed to room temperature, and stirred at the same temperature for 1 hour. The reaction mixture was added with n-hexane (25 mL), and the mixture was filtered through Celite. The filtrate was washed successively with water, saturated aqueous sodium hydrogencarbonate, and saturated brine, dried over sodium sulfate, and evaporated under reduced pressure. The resulting residue was distilled under reduced pressure (56° C., 0.7 mmHg) to obtain 5.45 g of (S)-1-bromo-1-[3,5-bis(trifluoromethyl)phenyl]ethane as colorless oil.

1. stirringstirred at the same temperature for 1 hour
2. filtrationthe mixture was filtered through Celite
3. washThe filtrate was washed successively with water, saturated aqueous sodium hydrogencarbonate, and saturated brine
4. dry with materialdried over sodium sulfate
5. customevaporated under reduced pressure
6. distillationThe resulting residue was distilled under reduced pressure (56° C., 0.7 mmHg)