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 resulting suspension was heated to reflux. After 1.75 h stirring at reflux, the RM was allowed to cool with stirring and stirred for 18 h at it before further cooling with an ice/NaCl bath, and a solid was collected by filtration. The solid was then triturated twice with refluxing acetone (10 mL then 15 mL) before filtering and drying under vacuum at 40° C. to give the title product as a beige solid. HPLC: tR 3.47 min (method D). MS: 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 resulting suspension was heated to reflux
2. temperatureat reflux
3. temperatureto cool
4. stirringwith stirring
5. stirringstirred for 18 h at it
6. temperaturebefore further cooling with an ice/NaCl bath
7. filtrationa solid was collected by filtration
8. customThe solid was then triturated twice with refluxing acetone (10 mL
9. filtration15 mL) before filtering
10. customdrying under vacuum at 40° C.