反应详情

To a solution of 4-bromo-2-(trifluoromethyl)phenol (4.37 g) in N,N-dimethylformamide (40 ml) were added potassium carbonate (3.75 g) and benzyl bromide (2.59 ml), and the mixture was stirred for 12 hours at room temperature. To the reaction mixture was added water, and the resulting mixture was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate. After the solvent was removed under reduced pressure, purification of the residue by flash column chromatography on silica gel (eluent: hexane/ethyl acetate=10/1) gave benzyl 4-bromo-2-(trifluoromethyl)phenyl ether (3.37 g). To a stirred solution of the obtained benzyl 4-bromo-2-(trifluoromethyl)phenyl ether (2.05 g) in diethyl ether (20 ml) was added 1.46M tert-butyl lithium solution in pentane (11.4 ml) at −100° C., and the mixture was stirred for 5 minutes. An excess amount of ethylene oxide was added to the reaction mixture, and the mixture was gradually allowed to warm up to −50° C. After a saturated aqueous ammonium chloride solution was added to the reaction mixture, the resulting mixture was allowed to warm up to room temperature and extracted with ethyl acetate. The extract was washed with brine and dried over anhydrous magnesium sulfate. After the solvent was removed under reduced pressure, purification of the residue by flash column chromatography on silica gel (eluent: hexane/ethyl acetate=2/1) gave 4′-benzyloxy-3′-(trifluoromethyl)phenethyl alcohol (1.46 g).

1. extractionthe resulting mixture was extracted with ethyl acetate
2. washThe extract was washed with water
3. dry with materialdried over anhydrous magnesium sulfate
4. customAfter the solvent was removed under reduced pressure, purification of the residue by flash column chromatography on silica gel (eluent: hexane/ethyl acetate=10/1)