Oxalyl chloride → 4,6-dimethoxy-2,3-dihydro-1H-indole-2,3-dione

HRID 749184Notes

Reaction equation

HRID 749184 reaction equation
Cl.[CH3:2][O:3][C:4]1[CH:5]=[C:6]([CH:8]=[C:9]([O:11][CH3:12])[CH:10]=1)[NH2:7].[C:13](Cl)(=[O:17])[C:14](Cl)=[O:15]>>[CH3:12][O:11][C:9]1[CH:10]=[C:4]([O:3][CH3:2])[CH:5]=[C:6]2[C:8]=1[C:13](=[O:17])[C:14](=[O:15])[NH:7]2

Participants

3

Reactant 2

HCID 65578Oxalyl chlorideHCID 218603Benzenamine, 3,5-dimethoxy-, hydrochloride (1:1)

Product 1

HCID 115575224,6-dimethoxy-2,3-dihydro-1H-indole-2,3-dioneYield 46%

Procedure

3,5-Dimethoxyaniline hydrochloride (80.21 g, 0.424 mol) was added cautiously to oxalyl chloride (136 ml, 1.56 mol) and the solution heated at reflux for 3 hours. The solution was cooled and concentrated in vacuo. Methanol (300 ml) was added to the residue and the mixture heated at reflux for 1 hour. The reaction was allowed to cool, and the resulting precipitate filtered and washed with methanol to yield 4,6-dimethoxyisatin (40.4 g, 46%) as a yellow solid.

Workup

  1. temperaturethe solution heated
  2. temperatureat reflux for 3 hours
  3. temperatureThe solution was cooled
  4. concentrationconcentrated in vacuo
  5. additionMethanol (300 ml) was added to the residue
  6. temperaturethe mixture heated
  7. temperatureat reflux for 1 hour
  8. temperatureto cool
  9. filtrationthe resulting precipitate filtered
  10. washwashed with methanol

Sources & evidence

ORD record
ord-753bbdacddd84f438d3f1eb99a4eacb4
Source dataset
uspto-grants-2008_07
Patent number
US07402585B2

Reaction notes

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