反应详情

To a three-neck flask (2,000 ml) was added concentrated nitric acid (500 ml). The mixture was cooled in an ice-water bath. Concentrated sulfuric acid (500 ml) was dropwise added to the mixture under mechanical stirring. After addition, the temperature of the resulting mixture was maintained below 15° C. Methyl 2-acetylamino-4-fluoro-benzoate (105.5 g, 0.5 mol) was slowly added. The resultant mixture was kept in an ice-water bath for 40 min with stirring. Then the mixture was poured into ice water (8 L). A large number of yellow solids precipitated. The mixture was stood for 10 min and filtered in vacuo. The filter cake was washed with lots of water and then transferred in water (2 L). The pH of the solution was adjusted to 7 with ammonia liquor under stirring and filtered in vacuo. The filter cake was dried by baking and recrystallized with ethyl acetate.

1. temperatureThe mixture was cooled in an ice-water bath
2. additionAfter addition
3. temperaturethe temperature of the resulting mixture was maintained below 15° C
4. customA large number of yellow solids precipitated
5. filtrationfiltered in vacuo
6. washThe filter cake was washed with lots of water
7. stirringunder stirring
8. filtrationfiltered in vacuo
9. customThe filter cake was dried
10. customrecrystallized with ethyl acetate