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

HRID 130323Notes

Reaction equation

HRID 130323 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 100%

Procedure

12 g (63 mmol) of 3,5-dimethoxyaniline hydrochloride and 20 ml (230 mol) of oxalyl chloride were stirred at 165° C. for 30 min. The excess of oxalyl chloride was distilled (the color of the reaction mixture changed from dark-red to green-yellow). The reaction mixture was cooled and methanol was added. The resulting suspension was heated then filtered, washed with methanol and dried to yield 13 g of 4,6-dimethoxyindole-2,3-dione (100% yield).

Workup

  1. distillationThe excess of oxalyl chloride was distilled (the color of the reaction mixture
  2. temperatureThe reaction mixture was cooled
  3. additionmethanol was added
  4. temperatureThe resulting suspension was heated
  5. filtrationthen filtered
  6. washwashed with methanol
  7. customdried

Sources & evidence

ORD record
ord-37dc510889a84c359231f537edcf0396
Source dataset
uspto-grants-2008_06
Patent number
US07381730B2

Reaction notes

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