4-Bromo-1-fluoro-2-nitrobenzene → 4-Bromo-7-fluoroindole

HRID 475216Notes

Reaction equation

HRID 475216 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([F:8])=[C:4]([N+:9]([O-])=O)[CH:3]=1.[CH:12]([Mg]Br)=[CH2:13]>C1COCC1>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([F:8])=[C:4]2[C:3]=1[CH:12]=[CH:13][NH:9]2

Participants

4

Reactant 2

HCID 27363284-Bromo-1-fluoro-2-nitrobenzeneHCID 178418507HCID 178418507, compound

Product 1

HCID 38225414-Bromo-7-fluoroindoleYield 12%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 4-bromo-1-fluoro-2-nitrobenzene (1.1 g, 5.0 mmol) in THF (20 mL) at −40° C. under nitrogen atmosphere was added slowly vinylmagnesium bromide (1 M in THF, 15.5 mL, 15.5 mmol). The reaction mixture was stirred for 1.5 h then quenched with saturated NH4Cl aqueous solution (10 mL). The mixture was partitioned between EtOAc (300 mL) and water (50 mL). The organic layer was separated, washed with brine, dried (MgSO4), filtered and evaporated in vacuo. The residue was purified by SiO2 chromatography eluting with 2.5% EtOAc/petroleum ether to afford 0.125 g (12%) of 4-bromo-7-fluoro-1H-indole (110) as brown oil: MS (ESI) m/z=214 [M−1]+.

Workup

  1. customthen quenched with saturated NH4Cl aqueous solution (10 mL)
  2. customThe mixture was partitioned between EtOAc (300 mL) and water (50 mL)
  3. customThe organic layer was separated
  4. washwashed with brine
  5. dry with materialdried (MgSO4)
  6. filtrationfiltered
  7. customevaporated in vacuo
  8. customThe residue was purified by SiO2 chromatography
  9. washeluting with 2.5% EtOAc/petroleum ether

Sources & evidence

ORD record
ord-576b634e657c4d478777d945604acdd0
Source dataset
uspto-grants-2014_01
Patent number
US08637537B2

Reaction notes

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