反应详情

温度

80 °C

5-Chloro-2-fluoro-toluene (100 g, 692 mmol) was dissolved in ethylacetate (300 ml) at 20° C. To this solution N-bromosuccinimide (147.7 g, 830 mmol) and dibenzoyl peroxide (2 g, 8.25 mmol) was added. The mixture was stirred at 80° C. for 3 hours. Heptane (300 ml) was added and the solution was cool to 0° C. whereupon succinimide precipitates. After filtration and washing with heptane, the residue was washed with water (1500 ml). The filtrate was concentrated in vacuo to dryness, yielding 162 grams of crude 5-chloro-2-fluoro-benzylbromide. Purification of the crude product (141 grams) was done by vacuum distillation at 99° C. and 33 mbar, this 5-chloro-2-fluoro-benzylbromide (99 grams, 75%). Purity according to GC is 87.1% a/a.

1. customprecipitates
2. filtrationAfter filtration
3. washwashing with heptane
4. washthe residue was washed with water (1500 ml)
5. concentrationThe filtrate was concentrated in vacuo to dryness