反应详情

温度

88 °C

To methyl 2,5-difluoro-4-methylbenzoate (Preparation 26, 55 g, 0.29 mol) in carbon tetrachloride (0.4 L) was added N-bromosuccinimide (52.6 g, 0.29 mol) and dibenzoyl peroxide (1 g, 3.5 mmol) and heated at 88° C. for 5 hours under a nitrogen atmosphere. The reaction mixture was cooled to room temperature and allowed to stand for 18 hours, then washed with water (400 mL), brine (100 mL), dried over sodium sulphate and concentrated in vacuo. The resulting solid was triturated with n-heptane (120 mL) and recrystallised from hot n-heptane (50 mL) to yield the title compound as a pale yellow solid (28.5 g, 36%).

1. temperatureThe reaction mixture was cooled to room temperature
2. washwashed with water (400 mL), brine (100 mL)
3. dry with materialdried over sodium sulphate
4. concentrationconcentrated in vacuo
5. customThe resulting solid was triturated with n-heptane (120 mL)
6. customrecrystallised from hot n-heptane (50 mL)