反应详情

A solution of 2.aminosulfonyl-6-isopropyl-4-methoxy-N,N-diethylbenzamide (429.6 g) in acetic acid (1.5 L) was refluxed for 20 hours, then cooled to room temperature. The solvent was removed under vacuum. The oily residue was dissolved in water (6 L) and the pH was adjusted to 1 with hydrochloric acid (6N). The crude product was collected by filtration, washed with water (2 L), dried at 60° C. under vacuum for 18 hours and recrystallized from ethyl acetate-hexane to give 4-isopropyl-6-methoxysaccharin (303 g, 91% yield, m.p. 188° C.).

1. customThe solvent was removed under vacuum
2. dissolutionThe oily residue was dissolved in water (6 L)
3. filtrationThe crude product was collected by filtration
4. washwashed with water (2 L)
5. customdried at 60° C. under vacuum for 18 hours
6. customrecrystallized from ethyl acetate-hexane