Sulfuric Acid → 4,5-Dimethylisatin

HRID 2110037Notes

Reaction equation

HRID 2110037 reaction equation
S(=O)(=O)(O)[OH:2].[CH3:6][C:7]1[CH:8]=[C:9]([NH:14][C:15](=[O:19])[CH:16]=NO)[CH:10]=[CH:11][C:12]=1[CH3:13]>O>[CH3:6][C:7]1[C:12]([CH3:13])=[CH:11][CH:10]=[C:9]2[C:8]=1[C:16](=[O:2])[C:15](=[O:19])[NH:14]2

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 6848890HCID 6848890, compound

Product 1

HCID 2665354,5-Dimethylisatin

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
85 °C

Procedure

To a solution of concentrated sulfuric acid (85 ml) in water (17 ml) there was slowly added N-(3,4-dimethylphenyl)-2-hydroxyimino-acetamide (30 g, 0.156 mmol), and the mixture was stirred at 85° C. for 2 hours. The obtained solution was poured into ice water, and the precipitated orange solid was filtered out. The obtained solid was dissolved in 10% aqueous sodium hydroxide, active carbon was added, and the mixture was stirred. The obtained solution was filtered, and acetic acid was used for acidification to obtain 4,5-dimethyl-1H-indole-2,3-dione as crystals.

Workup

  1. filtrationthe precipitated orange solid was filtered out
  2. dissolutionThe obtained solid was dissolved in 10% aqueous sodium hydroxide
  3. additionactive carbon was added
  4. stirringthe mixture was stirred
  5. filtrationThe obtained solution was filtered

Sources & evidence

ORD record
ord-4a7d4af45a534f56a219fb39da06d894
Source dataset
uspto-grants-2009_04
Patent number
US07517875B2

Reaction notes

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