反应详情

6-Bromo-3-fluoro-4-nitro-1-(phenylsulfonyl)-1H-indazole (5.9 g, 14.74 mmol) was suspended in acetic acid (60 ml) and to it added iron powder (4.12 g, 73.7 mmol). The suspension was heated to reflux for 2 h, then the reaction mixture was cooled, diluted with 100 ml EtOAc and filtered through celite. The filter cake was washed well with ethyl acetate then the filtrate basified till the colour moved from the aqueous layer to the organic (around pH 8-9). The biphasic system was then stirred for around 5 minutes and the aqueous layer turned cloudy. The layers were then separated, the aqueous washed with ethyl acetate and the combined organics washed with brine, dried (MgSO4), filtered and concentrated in vacuo. The residue was dry loaded onto a 330 g silica cartridge, purified on a 0-100% EtOAc/Cyclohexane gradient and the relevant fractions combined and concentrated to yield the title compound as a yellow solid (2.4 g).

1. temperatureThe suspension was heated
2. temperatureto reflux for 2 h
3. temperaturethe reaction mixture was cooled
4. filtrationfiltered through celite
5. washThe filter cake was washed well with ethyl acetate
6. customThe layers were then separated
7. washthe aqueous washed with ethyl acetate
8. washthe combined organics washed with brine
9. dry with materialdried (MgSO4)
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customThe residue was dry
13. custompurified on a 0-100% EtOAc/Cyclohexane gradient
14. concentrationconcentrated