反应详情

温度

100 °C

A mixture of 3-bromo-2,4,5-trifluorobenzonitrile (13.9 g) in concentrated sulfuric acid (8 ml) was heated for 20 minutes on an oil bath (100° C.), poured into ice water (350 ml). The resulting precipitate was collected by filtration and washed with water. The filtrate and washings were extracted 3 times with dichloromethane. The dichloromethane layer was washed with water saturated with sodium chloride, dried over anhydrous sodium sulfate and concentrated to give the residue. The combined mixture of the precipitate obtained previously and the residue was purified by silica gel chromatography eluting with dichloromethane dichloromethane:methanol (10:1) to give 3-bromo-2,4,5-trifluorobenzamide (8.7 g).

1. filtrationThe resulting precipitate was collected by filtration
2. washwashed with water
3. extractionThe filtrate and washings were extracted 3 times with dichloromethane
4. washThe dichloromethane layer was washed with water saturated with sodium chloride
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated
7. customto give the residue
8. additionThe combined mixture of the precipitate
9. customobtained previously
10. customthe residue was purified by silica gel chromatography
11. washeluting with dichloromethane dichloromethane:methanol (10:1)