反应详情

A mixture of 7-amino-3-isopropylamino-4H-1,2,4-benzothiadiazine 1,1-dioxide (0.18 g) and acetic anhydride (0.6 mL) in dioxane (2 mL) was stirred for 1 h at room temperature. The medium was then mixed with water (5 mL) and stirred for 1 h. The solvents were removed by distillation under reduced pressure and the residue of the crude title compound was recrystallized from methanol-water to give the title compound (yield: 0.16 g); m.p. 260-262° C.; IR (KBr): 3353, 3316, 3240, 3101, 3069, 2974, 1672, 1624, 1608, 1581, 1546, 1497, 1467, 1391, 1279, 1159, 1142, 1123, 1104 cm−1; 1H-NMR (DMSO-d6, HMDS; d ppm): 1.10 (d, 6H, 2×CH3), 2.00 (s, 3H, COCH3), 3.90 (m, 1H, NH—CH), 6.85 (bd, 1H, NH—CH), 7.05 (d, 1H, 5-H), 7.60 (bd, 1H, 6-H), 8.00 (bs, 1H, 8-H), 10.00 (bs, 1H, CONH), 10.10 (bs, 1H, NH).

1. stirringstirred for 1 h
2. customThe solvents were removed by distillation under reduced pressure
3. customthe residue of the crude title compound was recrystallized from methanol-water