反应详情

5 gm (25.2 mmols) of 3-amino-4-hydroxy-1,2-benzoisothiazole-1,1-dioxide and 2.02 gm (50.5 mmols) of sodium hydroxide were refluxed in 15 ml of water for 6.5 hours. Subsequently, the solution was treated with activated charcoal at 60° C. and filtered. At 60° C. the filtrate was acidified with concentrated aqueous hydrochloric acid (about 5 ml, 0.06 mol). The resulting precipitate was filtered off, dried and recrystallized from water. 4.62 gm (92% of theory) of 4-hydroxy-1,2-benzoisothiazol-3(2H)-one-1,1-dioxide were obtained.

1. filtrationfiltered
2. customAt 60° C.
3. filtrationThe resulting precipitate was filtered off
4. customdried
5. customrecrystallized from water