反应详情

温度

70 °C

10 ml of water are added with due care to 75 ml of concentrated sulphuric acid; the temperature rises to 70° C. 0.105 mole (33 g) of 2,5-difluoro-4-nitro-N-benzenesulphonylaniline prepared in the previous stage is then added. The temperature is maintained at 70° C. for 2 hours. The reaction mixture is poured onto 1 kg of ice and water and the expected product precipitates. After filtration and washing to neutrality the product is recrystallized from 100 ml of 96° ethanol. It melts at 153° C.

1. customrises to 70° C
2. additionis then added
3. customthe expected product precipitates
4. filtrationAfter filtration
5. washwashing to neutrality the product
6. customis recrystallized from 100 ml of 96° ethanol