Methyl p-toluenesulfonate → 5-Bromo-1-methyl-1H-indole

HRID 381325Notes

Reaction equation

HRID 381325 reaction equation
[H-].[Na+].[Br:3][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][CH:8]=[CH:7]2.[C:13]1(C)C=CC(S(OC)(=O)=O)=CC=1>CN(C)C=O>[Br:3][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[N:9]([CH3:13])[CH:8]=[CH:7]2

Participants

5

Reactant 3

HCID 6645Methyl p-toluenesulfonateHCID 24758Sodium hydrideHCID 249055-Bromoindole

Product 1

HCID 2857575-Bromo-1-methyl-1H-indoleYield 98.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

Sodium hydride (440 mg of a 60% dispersion in paraffin wax) was added to a stirred solution of 5-bromoindole (1.96 g, 10 mmol) in dimethylformamide (20 ml) at ambient temperature under a nitrogen atmosphere. After 30 minutes methyl p-toluenesulphonate (2.05 g, 11 mmol) was added. After 20 hours the mixture was partitioned between diethyl ether and water. The organic layer was separated and washed twice with water. The organic layer was dried (magnesium sulphate) and the solvent was removed in vacuo. The residue was purified by flash column chromatography (using 50% hexane, 50% dichloromethane as eluant) to give 2.07 g of product as a waxy solid.

Workup

  1. customAfter 20 hours the mixture was partitioned between diethyl ether and water
  2. customThe organic layer was separated
  3. washwashed twice with water
  4. dry with materialThe organic layer was dried (magnesium sulphate)
  5. customthe solvent was removed in vacuo
  6. customThe residue was purified by flash column chromatography (using 50% hexane, 50% dichloromethane as eluant)

Sources & evidence

ORD record
ord-df28c290cf814efd8662593aa511ce2e
Source dataset
uspto-grants-2001_10
Patent number
US06306852B1

Reaction notes

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