反应详情

3.2 g of benzenesulfonamide are introduced at from 0°-5° C. into 50 ml of abs. pyridine and, while stirring at that temperature, a solution of 3.9 g of benzo-1,2,3-thiadiazole-7-carboxylic acid chloride in20 ml of methylene chloride is added dropwise. The mixture is stirred overnight and then poured onto ice-water, rendered slightly acidic with hydrochloric acid and extracted with methylene chloride, and the extracts are washed with water, dried and concentrated by evaporation. The residue is dissolved warm in tetrahydrofuran, treated with some silica gel, filtered, concentrated by evaporation and then recrystallised from tetrahydrofuran/hexane. The title compound resulting melts at 231°-233° C.

1. additionpoured onto ice-water
2. extractionextracted with methylene chloride
3. washthe extracts are washed with water
4. customdried
5. concentrationconcentrated by evaporation
6. dissolutionThe residue is dissolved
7. temperaturewarm in tetrahydrofuran
8. additiontreated with some silica gel
9. filtrationfiltered
10. concentrationconcentrated by evaporation
11. customrecrystallised from tetrahydrofuran/hexane