反应详情

To a solution of 1-(4-fluoro-3-cyanophenyl)-3-trifluoromethyl-5-methylpyrazole (4.0 g, 14.9 mmol) in CCl4 (75 mL) was added NBS (5.3 g, 29.7 mmol) and benzylperoxide (0.2 g, 1.49 mmol). The reaction was brought to reflux overnight. The next day the CCl4 was evaporated and the residue was partitioned between ethyl acetate and sodium bicarbonate (sat.). The organic phase was washed with water, brine, dried over sodium sulfate, filtered and concentrated. Flash chromatography gave 1-(4-fluoro-3-cyanophenyl)-3-trifluoromethyl-5-bromomethylpyrazole (2.6 g, 50% yield) as pure compound: MS (CI): 348 (M+H)+ (100%).

1. temperatureto reflux overnight
2. customThe next day the CCl4 was evaporated
3. customthe residue was partitioned between ethyl acetate and sodium bicarbonate (sat.)
4. washThe organic phase was washed with water, brine
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated