Sodium Hydroxide → 5-Bromo-3-methyl-1H-indole

HRID 1403492Notes

Reaction equation

HRID 1403492 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[C:5]2[CH:11]=O.[H-].[H-].[H-].[H-].[Li+].[Al+3].[OH-].[Na+]>C1COCC1>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[C:5]2[CH3:11]

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 701375-Bromoindole-3-carbaldehydeHCID 21226445Aluminium lithium hydride

Product 1

HCID 2547075-Bromo-3-methyl-1H-indoleYield 73%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 5-bromo-1H-indole-3-carbaldehyde (5.0 g, 22.3 mmol) in THF (80 mL) was added LiAlH4 (1.70 g, 44.6 mmol). The resulting solution was stirred for 2 h under reflux, then poured into 1N NaOH solution (150 mL), extracted with ethyl acetate (3×100 mL), dried over anhydrous sodium sulfate, and then concentrated under vacuum to give a residue, which was purified via silica gel chromatography (3% ethyl acetate in petroleum ether) to afford 5-bromo-3-methyl-1H-indole as a white solid (3.4 g, 73%).

Workup

  1. temperatureunder reflux
  2. extractionextracted with ethyl acetate (3×100 mL)
  3. dry with materialdried over anhydrous sodium sulfate
  4. concentrationconcentrated under vacuum
  5. customto give a residue, which
  6. customwas purified via silica gel chromatography (3% ethyl acetate in petroleum ether)

Sources & evidence

ORD record
ord-a0fc2e2a92644337ad2842c25f910e44
Source dataset
uspto-grants-2014_12
Patent number
US08912188B2

Reaction notes

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