6-Bromo-3-fluoro-4-nitro-1-(phenylsulfonyl)-1H-indazole → 6-Bromo-3-fluoro-1-(phenylsulfonyl)-1H-indazol-4-amine
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.C(OCC)(=O)C.[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]=1Participants
Procedure
6-Bromo-3-fluoro-4-nitro-1-(phenylsulfonyl)-1H-indazole (5.9 g) was suspended in acetic acid (60 ml) and iron powder (4.12 g) was added. The suspension was heated to reflux. After 2 h the reaction mixture was diluted with ethyl acetate (100 ml) and filtered through celite. The filter cake was washed well with ethyl acetate then the filtrate basified to pH 8-9. The biphasic system was then stirred for ˜5 min. The layers were then separated, the aq washed with ethyl acetate and the combined organics washed with brine, dried (magnesium sulphate), filtered and concentrated in vacuum to yield a crude loaded onto a 330 g silica cartridge, purified on a 0-100% ethyl acetate:cyclohexane gradient and the relevant fractions combined and concentrated to yield the title compound, 2.4 g as a yellow solid.
Workup
- temperatureThe suspension was heated to reflux
- filtrationfiltered through celite
- washThe filter cake was washed well with ethyl acetate
- customThe layers were then separated
- washthe aq washed with ethyl acetate
- washthe combined organics washed with brine
- dry with materialdried (magnesium sulphate)
- filtrationfiltered
- concentrationconcentrated in vacuum
- customto yield a crude
- custompurified on a 0-100% ethyl acetate
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-d2b32050165c42c3a754036c25e9ffcc
- Source dataset
- uspto-grants-2016_05
- Patent number
- US09326987B2
Reaction notes
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