反应详情

To a solution of 1-(3-cyano-4-fluorophenyl)-3-trifluoromethyl-5-methyl pyrazole(4.0 g, 14.87 mmol) in carbon tetrachloride(50 mL) was added NBS(2.65 g, 14.87 mmol) and benzoyl peroxide(0.36 g, 1.48 mmol). The reaction mixture was brought to reflux overnight. Solvent was removed on rotary evaporator under reduced pressure. Residue was partitioned between ethyl acetate(80 mL) and sodium bicarbonate(sat. 80 mL). Organic phase was separated and washed with water(60 mL); dried over sodium sulfate; filtered, concentrated and subjected to silica-gel flash chromatography (ethyl acetate : hexane, 1:10) to afford 1-(3-cyano-4-fluorophenyl)-3-trifluoromethyl-5-bromomethyl pyrazole(2.5 g). CI mass spectrum m/z (rel. intensity) 348 (M+H, 100).

1. temperatureto reflux overnight
2. customSolvent was removed on rotary evaporator under reduced pressure
3. customResidue was partitioned between ethyl acetate(80 mL) and sodium bicarbonate(sat. 80 mL)
4. customOrganic phase was separated
5. washwashed with water(60 mL)
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated