反应详情

25.0 g (145 mmol) of 4-aminobenzenesulfonamide was added to a mixed solution of 80 ml of water and 50 ml of concentrated hydrochloric acid, followed by stirring. To the mixture was added dropwise an aqueous solution (20 ml) containing 10.5 g (152 mmol) of sodium nitrite at −13° C. to −10° C. over 15 minutes. After 10 minutes, the reaction solution was added to a sulfur dioxide saturated mixture solution (solution prepared by saturating a mixed solution of 150 ml of acetic acid and 12.5 ml of concentrated hydrochloric acid with sulfur dioxide and then adding 3.7 g of cuprous chloride thereto) at −30° C. under stirring. After one hour, 500 ml of ice-water was added to the reaction solution, and the precipitates were collected by filtration. The precipitates were dissolved in a mixed solution of 450 ml of toluene and 150 ml of ethyl acetate. After filtering off the insoluble matters, the filtrate was extracted with ethyl acetate. The organic layer was successively washed with an aqueous saturated sodium bicarbonate and brine, and dried over magnesium sulfate. The solvent was evaporated, and 100 ml of toluene was added to the residue. The crystals were collected by filtration, to give 20.9 g of the title compound.

1. customprepared
2. concentrationby saturating a mixed solution of 150 ml of acetic acid and 12.5 ml of concentrated hydrochloric acid with sulfur dioxide
3. additionadding 3.7 g of cuprous chloride
4. stirring) at −30° C. under stirring
5. waitAfter one hour
6. addition500 ml of ice-water was added to the reaction solution
7. filtrationthe precipitates were collected by filtration
8. dissolutionThe precipitates were dissolved in a mixed solution of 450 ml of toluene and 150 ml of ethyl acetate
9. filtrationAfter filtering off the insoluble matters
10. extractionthe filtrate was extracted with ethyl acetate
11. washThe organic layer was successively washed with an aqueous saturated sodium bicarbonate and brine
12. dry with materialdried over magnesium sulfate
13. customThe solvent was evaporated
14. addition100 ml of toluene was added to the residue
15. filtrationThe crystals were collected by filtration