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

HRID 1840816Notes

Reaction equation

HRID 1840816 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][C:9](O)=[O:10])=[C:4]([N+:12]([O-])=O)[CH:3]=1.S(=O)(=O)(O)O>C(O)C.[Zn]>[Br:1][C:2]1[CH:3]=[C:4]2[C:5]([CH2:8][C:9](=[O:10])[NH:12]2)=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 1118Sulfuric AcidHCID 2715514-Bromo-2-nitrophenylacetic Acid

Product 1

HCID 27732896-bromo-2,3-dihydro-1H-indol-2-oneYield 90%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 702EthanolSolvent

Procedure

4-Bromo-2-nitrophenylacetic acid (0.26 g), 0.26 g zinc powder and 3 mL 50% sulfuric acid in 5 mL of ethanol were heated at 100° C. overnight. The reaction mixture was filtered, diluted with a little acetic acid, concentrated to remove ethanol, diluted with water and extracted twice with ethyl acetate. The combined extracts were washed with brine, dried over anhydrous sodium sulfate and concentrated to give 0.19 g (90% yield) of 6-bromo-2-oxindole as a yellow solid.

Workup

  1. filtrationThe reaction mixture was filtered
  2. additiondiluted with a little acetic acid
  3. concentrationconcentrated
  4. customto remove ethanol
  5. additiondiluted with water
  6. extractionextracted twice with ethyl acetate
  7. washThe combined extracts were washed with brine
  8. dry with materialdried over anhydrous sodium sulfate
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-979c07ac9e0b47d6a02fe478de9fd986
Source dataset
uspto-grants-2004_01
Patent number
US06683082B2

Reaction notes

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