反应详情

A mixture of 2-amino-5-bromo-benzenethiol (20 g, 0.1 mol), ethyl bromoacetate (19 g, 0.1 mol), and sodium bicarbonate (8.8 g, 0.1 mol) in DMF (200 ml) was heated to reflux for 2 hours. The mixture was diluted with water and extracted with ethyl acetate (2×100 mL). The combined organic extracts were washed with water, then brine, dried (MgSO4) and evaporated to obtain the crude 7-bromo -4H-benzo[1,4]thiazin-3-one (20 g, 82%). A small portion of sample was recrystallized from ethanol to afford pure 7-bromo-4H-benzo[1,4]thiazin-3-one: mp 212-213° C.; MS (EI) m/z 243/245 (M+).

1. temperaturewas heated
2. temperatureto reflux for 2 hours
3. extractionextracted with ethyl acetate (2×100 mL)
4. washThe combined organic extracts were washed with water
5. dry with materialbrine, dried (MgSO4)
6. customevaporated