反应详情

温度

100 °C

A solution of 3-bromo-2-chloro-4,5-difluorobenzonitrile (9.8 g) in concentrated sulfuric acid (10 ml) was stirred at 100° C. for 35 minutes. After cooling, 18N sulfuric acid (50 ml) and water (10 ml) were added to the reaction mixture. The reaction mixture was stirred at 100° C. for 4 hours and then poured into ice water (300 ml). The resulting precipitate was collected by filtration, washed with water sufficiently and recrystallized from dichloromethane-n-hexane to give the title compound (9.24 g) as colorless prisms, mp 137.5°-139.5° C.

1. temperatureAfter cooling
2. filtrationThe resulting precipitate was collected by filtration
3. washwashed with water sufficiently
4. customrecrystallized from dichloromethane-n-hexane