反应详情

温度

80 °C

6-Bromo-4-nitro-2-(tetrahydro-2H-pyran-2-yl)-2H-indazole (6 g, 18.40 mmol), iron filings (3.29 g, 58.9 mmol) and ammonium chloride (0.492 g, 9.20 mmol) were weighed to a 250 ml round-bottomed flask and ethanol (60 ml) then water (18 ml) was added. The reaction was heated to 80° C. for 2.5 hr. The reaction mixture was cooled. 100 ml Ethyl acetate and 50 ml water was added. There was no visible separation of layers so the reaction was evaporated to remove the ethyl acetate and ethanol. 250 ml Ethyl acetate was then added and the organic layer was washed with a further 50 ml water, before passing through a hydrophobic frit. The organic layer was evaporated to dryness to give 6 g crude material. The aqueous layer was further extracted with DCM and then ethyl acetate. The DCM extract was evaporated to dryness to give a small amount of impure product that was discarded. The 6 g batch of crude material was purified by column chromatography on silica (120 g silica column, ISCO companion technology) eluting with a gradient of 1-2% methanol in DCM over 25 minutes. Fractions containing desired material were combined and evaporated to dryness to afford the title compound (3.95 g).

1. temperatureThe reaction mixture was cooled
2. customno visible separation of layers so the reaction
3. customwas evaporated
4. customto remove the ethyl acetate and ethanol
5. addition250 ml Ethyl acetate was then added
6. washthe organic layer was washed with a further 50 ml water
7. customThe organic layer was evaporated to dryness
8. customto give 6 g crude material
9. extractionThe aqueous layer was further extracted with DCM
10. extractionThe DCM extract
11. customwas evaporated to dryness
12. customto give a small amount of impure product that
13. customThe 6 g batch of crude material was purified by column chromatography on silica (120 g silica column, ISCO companion technology)
14. washeluting with a gradient of 1-2% methanol in DCM over 25 minutes
15. additionFractions containing desired material
16. customevaporated to dryness