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

HRID 429117Notes

Reaction equation

HRID 429117 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-c47fc00aa2664427a54d5b8aca9018c5
Source dataset
uspto-grants-2001_11
Patent number
US06316429B1

Reaction notes

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