反应详情

A solution of (4-bromophenoxy)difluoromethane (3 g) and triisopropyl borate (3.42 ml) in tetrahydrofuran (15 ml) was cooled to −78° C. under argon atmosphere, and thereto was added a solution of n-butyl lithium (1.59 M hexane solution, 3.42 ml). The mixture was stirred at room temperature overnight. Added thereto was 6N aqueous hydrochloric acid at 0° C., and the mixture was extracted with ethyl acetate. The extract was washed with brine, and dried over magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was triturated with cold hexane to give 4-(difluoromethoxy)phenylboronic acid (1.88 g) as colorless solid.

1. additionAdded
2. customat 0° C.
3. extractionthe mixture was extracted with ethyl acetate
4. washThe extract was washed with brine
5. dry with materialdried over magnesium sulfate
6. customThe solvent was evaporated under reduced pressure
7. customthe residue was triturated with cold hexane