反应详情

温度

100 °C

50 ml of water and 200 ml of concentrated sulfuric acid were added to 84.4 g (0.42 mole) of 2-amino-4-methoxy-3,5,6-trifluorobenzonitrile (XX) [prepared as described in Step (E2) above]. The mixture was then stirred at 100° C. for 1 hour, after which 150 ml of water were added thereto, and the mixture was stirred at 110°-120° C. for a further 2 hours. The reaction mixture was then allowed to stand to cool to room temperature, after which it was poured into ice-water and neutralized with potassium carbonate. The crystalline substance which precipitated was extracted with ethyl acetate; the extract was washed with water and dried over anhydrous sodium sulfate; and the solvent was removed by evaporation under reduced pressure to afford 57.6 g of 3-methoxy-2,4,5-trifluoroaniline (XXIII) as colorless needles melting at 45°-47° C.

1. stirringthe mixture was stirred at 110°-120° C. for a further 2 hours
2. temperatureto cool to room temperature
3. customThe crystalline substance which precipitated
4. extractionwas extracted with ethyl acetate
5. washthe extract was washed with water
6. dry with materialdried over anhydrous sodium sulfate
7. customand the solvent was removed by evaporation under reduced pressure