Hexane → (R)-1-bromo-1-[3,5-bis(trifluoromethyl)phenyl]ethane

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. This reaction mixture was added dropwise with a solution of (S)-1-[3,5-bis(trifluoromethyl)phenyl]ethanol (1) (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 for 1 hour at the same temperature. The reaction mixture was added with n-hexane (25 mL), and the mixture was filtered through Celite. The filtrate was successively washed with water, saturated aqueous sodium hydrogencarbonate, and saturated brine, dried over sodium sulfate, and then evaporated under reduced pressure. The resulting residue was distilled under reduced pressure (56° C., 0.7 mmHg) to obtain 5.52 g of (R)-1-bromo-1-[3,5-bis(trifluoromethyl)phenyl]ethane (2) as colorless oil (yield: 88.6%).

1. stirringstirred for 1 hour at the same temperature
2. filtrationthe mixture was filtered through Celite
3. washThe filtrate was successively washed 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)

ORD record

ord-5b8f288919f142fe900d753a645c3f92

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08906895B2