2-Methylindole → 5-Bromo-2-methylindole

HRID 1403456Notes

Reaction equation

HRID 1403456 reaction equation
[CH3:1][C:2]1[NH:3][C:4]2[C:9]([CH:10]=1)=[CH:8][CH:7]=[CH:6][CH:5]=2.[Br:11]Br>S(=O)(=O)(O)O.[O-]S([O-])(=O)=O.[Ag+].[Ag+]>[Br:11][C:7]1[CH:8]=[C:9]2[C:4](=[CH:5][CH:6]=1)[NH:3][C:2]([CH3:1])=[CH:10]2

Participants

5

Reactant 2

HCID 72242-MethylindoleHCID 24408Bromine

Product 1

HCID 50039685-Bromo-2-methylindoleYield 75%

Reagents, catalysts & solvents 2

HCID 159865Silver sulfateCatalystHCID 1118Sulfuric AcidSolvent

Procedure

To a solution of 2-methyl-1H-indole (5.0 g, 38.12 mmol) in sulfuric acid (80 mL) was added Ag2SO4 (12.5 g, 40.06 mmol) with ice cooling, and the solution was stirred for 30 min. Then Br2 (6.4 g, 40.05 mmol) was added to the solution dropwise over 30 min. After the solution was stirred for 4 h at room temperature, the reaction was then quenched by the addition of water/ice (300 mL). The reaction mixture was extracted with dichloromethane (3×200 mL) and the organic layers combined, dried over anhydrous sodium sulfate and concentrated in vacuo to afford 5-bromo-2-methyl-1H-indole as a light brown solid (6 g, 75%).

Workup

  1. stirringAfter the solution was stirred for 4 h at room temperature
  2. customthe reaction was then quenched by the addition of water/ice (300 mL)
  3. extractionThe reaction mixture was extracted with dichloromethane (3×200 mL)
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-099afcc770cf41f6a59edca7acb97aee
Source dataset
uspto-grants-2014_12
Patent number
US08912188B2

Reaction notes

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