反应详情

温度

80 °C

2-(4-nitrophenyl)-1,2-dihydro-3H-pyrazolo[4,3-c]cinnolin-3-one (11.4 g, 37.2 mmol) was suspended in a mixture of ethanol (100 ml) and water (100 ml). Iron powder (11.1 g, 200 mmol) and ammonium chloride (5.34 g, 100 mmol) were added. The mixture was heated to 80° C. overnight, cooled to room temperature and basified with potassium carbonate to pH 9-10. The solids were removed by filtration through a pad of Celite®. The filtrate was extracted with n-butanol (2×200 ml). The combined organic phases were concentrated under vacuum to give a dark red solid. The solid was triturated with methanol (100 ml), filtered and dried under vacuum. The title compound was isolated as a dark red powder (5.58 g, 20.1 mmol, 57%). LCMS: m/z 278 [M+H]+.

1. temperaturecooled to room temperature
2. customThe solids were removed by filtration through a pad of Celite®
3. extractionThe filtrate was extracted with n-butanol (2×200 ml)
4. concentrationThe combined organic phases were concentrated under vacuum
5. customto give a dark red solid
6. customThe solid was triturated with methanol (100 ml)
7. filtrationfiltered
8. customdried under vacuum