反应详情

A solution of 261.1 g (2.0 mol) of 1-chloro-3-fluorobenzene in 2000 ml of dry tetrahydrofuran under nitrogen is cooled to −78°. To the solution is added 960 ml (2.4 mol) of 2.5 M n-butyllithium in hexanes over a period of 40 minutes. After stirring for 2.5 hours, a slurry of 155 ml of bromine cooled to −78° is added over 30 minutes and the mixture is stirred for 40 minutes before warming to −10°. The reaction is quenched with an aqueous solution of 151.3 g (1.2 mol) of sodium sulfite and 16.0 g (0.4 mol) of sodium hydroxide in 500 ml of water. The organic layer is separated, the solvents are removed at ambient pressure, and the product is distilled at 92–96° (20 mm Hg) to obtain 2-bromo-3-fluoro-chlorobenzene as a colorless oil.

1. additionis added over 30 minutes
2. stirringthe mixture is stirred for 40 minutes
3. temperaturebefore warming to −10°
4. customThe organic layer is separated
5. customthe solvents are removed at ambient pressure
6. distillationthe product is distilled at 92–96° (20 mm Hg)