Hydrazine hydrate (1:1) → 4-Bromo-6-fluoro-1H-indole

HRID 888951Notes

Reaction equation

HRID 888951 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[C:4]([N+]([O-])=O)[C:3]=1[CH:12]=[CH:13][N:14]1CCCC1.O.NN>O1CCCC1.CO.[Ni].O>[Br:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[C:4]2[C:3]=1[CH:12]=[CH:13][NH:14]2

Participants

7

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 866380951-[2-(2-Bromo-4-fluoro-6-nitro-phenyl)-vinyl]-pyrrolidine

Product 1

HCID 247281734-Bromo-6-fluoro-1H-indoleYield 43%

Reagents, catalysts & solvents 4

HCID 935NickelCatalystHCID 887MethanolSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of crude 1-[2-(2-bromo-4-fluoro-6-nitro-phenyl)-vinyl]-pyrrolidine (2.74 g) in tetrahydrofuran (25 ml) and methanol (25 ml) was added Raney nickel, 50% slurry in water, active catalyst (5.0 ml) followed by careful addition of hydrazine monohydrate (0.63 ml). After stirring for 24 hours the reaction mixture was filtered through celite and the filtrate reduced in vacuo. The residue was purified by flash chromatography to give 4-bromo-6-fluoro-1H-indole (0.80 g).

Workup

  1. filtrationwas filtered through celite
  2. customThe residue was purified by flash chromatography

Sources & evidence

ORD record
ord-f9caa8fced0743f28ffc16471e8fa511
Source dataset
uspto-grants-2012_08
Patent number
US08252792B2

Reaction notes

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