反应详情

To acetic anhydride (80 mL) was added at rt 2-amino-5,6-dihydro-4H-benzothiazol-7-one (10 g, 59.4 mmol) and the yellow suspension was heated to reflux. After 1.75 h stirring at this temperature, the RM was allowed to cool with stirring, and stirred overnight at rt. After further cooling with an ice/NaCl bath, the suspension was filtered. The solid was then refluxed twice with acetone (10 mL then 15 mL) and filtered. The resulting solid was dried under vacuum at 40° C. overnight to afford the title compound as a beige solid (HPLC: tR 3.47 min (Method A3), M−H=211.1), 1H-NMR in DMSO-d6 (600 MHz): 12.55 (s, br, 1H); 2.84 (t, 2H); 2.48 (t, 2H); 2.17 (s, 3H); 2.065 (qt, 2H)).

1. temperaturethe yellow suspension was heated to reflux
2. temperatureto cool
3. stirringwith stirring
4. stirringstirred overnight at rt
5. temperatureAfter further cooling with an ice/NaCl bath
6. filtrationthe suspension was filtered
7. temperatureThe solid was then refluxed twice with acetone (10 mL
8. filtration15 mL) and filtered
9. customThe resulting solid was dried under vacuum at 40° C. overnight