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

HRID 457665Notes

Reaction equation

HRID 457665 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-33d24f32e6314146914dd901300698da
Source dataset
uspto-grants-2007_03
Patent number
US07189721B2

Reaction notes

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