反应详情

温度

120 °C

5-Chloro-2,3-dihydro-1,4-benzothiazine-3-one (2.0 g) and phosphorus pentasulfide (2.0 g) were added to pyridine (5 ml), followed by stirring at 120° C. for 20 minutes. The reaction mixture was then poured into a dilute hydrochloric acid (50 ml), and the precipitated crystals were filtered, washed with water, dried and recrystallized from ethanol to obtain 1.9 g of the objective 5-chloro-2,3-dihydro-1,4-benzothiazine-3-thione (m.p. 138°-140° C.).

1. filtrationthe precipitated crystals were filtered
2. washwashed with water
3. customdried
4. customrecrystallized from ethanol