反应详情

A solution of (R)-1-[3,5-bis(trifluoromethyl)phenyl]ethanol (optical purity, >99.5% ee; 100 mg; 0.39 mmol) in dehydrated diethyl ether (1.0 mL) was added with dehydrated pyridine (69.4 mg, 0.89 mmol) under an argon atmosphere. The mixture was slowly added dropwise with a solution of phosphorus tribromide (117.2 mg, 0.43 mmol) in dehydrated diethyl ether (0.5 mL) at −15 to −20° C., and the mixture was stirred at the same temperature for 2 hours, and then left standing at −5° C. for 48 hours. Then, the reaction mixture was added with cooled water (3 mL) under ice cooling, and the mixture was stirred at room temperature for 15 minutes, and then extracted with diethyl ether (10 mL). The organic layer was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (silica gel, 3.0 g; developing solvent, n-hexane) to obtain 17.6 mg of 1-bromo-1-[3,5-bis(trifluoromethyl)phenyl]ethane as colorless oil.

1. waitleft
2. waitstanding at −5° C. for 48 hours
3. stirringthe mixture was stirred at room temperature for 15 minutes
4. extractionextracted with diethyl ether (10 mL)
5. concentrationThe organic layer was concentrated under reduced pressure
6. customthe resulting residue was purified by silica gel column chromatography (silica gel, 3.0 g; developing solvent, n-hexane)