Dimethyl 2-methoxycarbonyl-6-nitrophenylmalonate → 2-oxo-2,3-dihydro-1H-indole-4-carboxylic acid

HRID 24316Notes

Reaction equation

HRID 24316 reaction equation
C[O:2][C:3]([C:5]1[CH:10]=[CH:9][CH:8]=[C:7]([N+:11]([O-])=O)[C:6]=1[CH:14](C(OC)=O)[C:15]([O:17]C)=O)=[O:4]>Cl>[C:3]([C:5]1[CH:10]=[CH:9][CH:8]=[C:7]2[C:6]=1[CH2:14][C:15](=[O:17])[NH:11]2)([OH:2])=[O:4]

Participants

3

Reactant 1

HCID 54355276Dimethyl 2-methoxycarbonyl-6-nitrophenylmalonate

Product 1

HCID 103973292-oxo-2,3-dihydro-1H-indole-4-carboxylic acidYield 38.1%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Procedure

Dimethyl 2-methoxycarbonyl-6-nitrophenylmalonate (3.0 g) was refluxed in 50 mL of 6 N hydrochloric acid overnight. The mixture was concentrated to dryness and refluxed for 2 hours with 1.1 g of tin(II) chloride in 20 mL of ethanol. The mixture was filtered through Celite, concentrated and chromatographed on silica gel (ethyl acetate:hexane:acetic acid) to give 0.65 g (37% yield) of 4-carboxy-2-oxindole as a white solid.

Workup

  1. concentrationThe mixture was concentrated to dryness
  2. temperaturerefluxed for 2 hours with 1.1 g of tin(II) chloride in 20 mL of ethanol
  3. filtrationThe mixture was filtered through Celite
  4. concentrationconcentrated
  5. customchromatographed on silica gel (ethyl acetate:hexane:acetic acid)

Sources & evidence

ORD record
ord-1a81ce7a720049cf895ea8736e140273
Source dataset
uspto-grants-2005_02
Patent number
US06855730B2

Reaction notes

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