6-Bromo-3-fluoro-4-nitro-1-(phenylsulfonyl)-1H-indazole → 6-Bromo-3-fluoro-1-(phenylsulfonyl)-1H-indazol-4-amine

HRID 244700Notes

Reaction equation

HRID 244700 reaction equation
[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([C:6]([F:20])=[N:7][N:8]2[S:11]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)(=[O:13])=[O:12])=[C:4]([N+:21]([O-])=O)[CH:3]=1>C(O)(=O)C.CCOC(C)=O.[Fe]>[Br:1][C:2]1[CH:3]=[C:4]([NH2:21])[C:5]2[C:6]([F:20])=[N:7][N:8]([S:11]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)(=[O:12])=[O:13])[C:9]=2[CH:10]=1

Participants

5

Reactant 1

HCID 583563926-Bromo-3-fluoro-4-nitro-1-(phenylsulfonyl)-1H-indazole

Product 1

HCID 583564216-Bromo-3-fluoro-1-(phenylsulfonyl)-1H-indazol-4-amineYield 44%

Reagents, catalysts & solvents 3

HCID 23925IronCatalystHCID 176Acetic AcidSolventHCID 8857Ethyl AcetateSolvent

Procedure

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).

Workup

  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

Sources & evidence

ORD record
ord-cc5b401d57ad424c80c767e4b4a5cf36
Source dataset
uspto-grants-2014_02
Patent number
US08658635B2

Reaction notes

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