反应详情

温度

0 °C

8.78 g (30 mmol) of 4-fluoro-2-(trifluoromethyl)-aniline is dissolved in 88 ml of dichloroethane with exclusion of moisture, 5.55 g (70 mmol) of pyridine is added and the solution is cooled to 0° C. With this temperature being maintained, a solution of 9.9 g (36 mmol) of 1,3-benzenedisulfonic acid dichloride in 50 ml of dichloroethane is instilled, it is stirred for 30 more minutes at 0° C. and for 5 hours more at room temperature. The suspension is shaken out three times with 2N hydrochloric acid and twice with water, the organic phase is dried on sodium sulfate, filtered, concentrated by evaporation and the residue is chromatographed on silica gel 60 (Merck) with ethyl acetate/hexane 1:1. The fractions of the corresponding polarity, concentrated by evaporation, yield 9.7 g (23.22 mmol)=77.4% of the theoretical yield is obtained of a partially crystalline product.

1. additionis added
2. temperatureWith this temperature being maintained
3. dry with materialtwice with water, the organic phase is dried on sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated by evaporation
6. customthe residue is chromatographed on silica gel 60 (Merck) with ethyl acetate/hexane 1:1
7. concentrationThe fractions of the corresponding polarity, concentrated by evaporation, yield 9.7 g (23.22 mmol)=77.4% of the
8. customtheoretical yield
9. customis obtained of a partially crystalline product