4-Bromo-2-nitrotoluene → 4-Bromo-7-methyl-1H-indole

HRID 475300Notes

Reaction equation

HRID 475300 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH3:8])=[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]([CH3:8])=[C:4]2[C:3]=1[CH:12]=[CH:13][NH:9]2

Participants

4

Reactant 2

HCID 1235464-Bromo-2-nitrotolueneHCID 178418507HCID 178418507, compound

Product 1

HCID 247292794-Bromo-7-methyl-1H-indoleYield 16%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 4-bromo-1-methyl-2-nitrobenzene (10 g) in THF (130 mL) was slowly added vinylmagnesium bromide (1 M in THF, 162 mL) at −40° C. under nitrogen atmosphere. The reaction mixture was stirred for 1.5 h and then quenched with sat'd. aq. NH4Cl (50 mL). The mixture was partitioned between EtOAc (500 mL) and water (150 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 1.54 g (16%) of 4-bromo-7-methyl-1H-indole (306) as brown solid: MS (ESI) m/z=209.9 [M+1]+.

Workup

  1. customat −40° C.
  2. customquenched with sat'd
  3. customThe mixture was partitioned between EtOAc (500 mL) and water (150 mL)
  4. customThe organic layer was separated
  5. washwashed with brine
  6. dry with materialdried (MgSO4)
  7. filtrationfiltered
  8. customevaporated in vacuo
  9. customThe residue was purified by SiO2 chromatography
  10. washeluting with 2.5% EtOAc/petroleum ether

Sources & evidence

ORD record
ord-1597ca50916d45d9b363bcb9efdab7e8
Source dataset
uspto-grants-2014_01
Patent number
US08637537B2

Reaction notes

Loading…