Sulfuric Acid → 6-bromo-3-methyl-2,3-dihydro-1H-indol-2-one

HRID 1942532Notes

Reaction equation

HRID 1942532 reaction equation
Br[C:2]1[NH:3][C:4]2[C:9]([C:10]=1[CH3:11])=[CH:8][CH:7]=[C:6]([Br:12])[CH:5]=2.S(=O)(=O)(O)[OH:14].O1CCOCC1>O>[Br:12][C:6]1[CH:5]=[C:4]2[C:9]([CH:10]([CH3:11])[C:2](=[O:14])[NH:3]2)=[CH:8][CH:7]=1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 312751,4-DioxaneHCID 135741552,6-dibromo-3-methyl-1H-indole

Product 1

HCID 2803186-bromo-3-methyl-2,3-dihydro-1H-indol-2-one

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To 2,6-dibromo-3-methyl-1H-indole (15.7 g) were added 3N aqueous sulfuric acid solution (100 ml) and dioxane (100 ml), and the mixture was refluxed for 5 hours. After the reaction was complete, water was added to the reaction solution, and the mixture was extracted with ethyl acetate solution. This ethyl acetate solution was washed with water and an aqueous sodium chloride solution, dried over magnesium sulfate, filtered, and concentrated. The obtained residue was purified by silica gel column chromatography (hexane/ethyl acetate=4/1) to give the title compound (11.2 g) as a brown crystal.

Workup

  1. temperaturethe mixture was refluxed for 5 hours
  2. extractionthe mixture was extracted with ethyl acetate solution
  3. washThis ethyl acetate solution was washed with water
  4. dry with materialan aqueous sodium chloride solution, dried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe obtained residue was purified by silica gel column chromatography (hexane/ethyl acetate=4/1)

Sources & evidence

ORD record
ord-474388bb84784cf79d8cab36be1433f8
Source dataset
uspto-grants-2013_03
Patent number
US08389511B2

Reaction notes

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