反应详情

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, 20 mL ethanol and 1.1 g of tin(II) chloride were added and the mixture was refluxed for 2 hours. The mixture was filtered through Celite, concentrated and chromatographed on silica gel using ethyl acetate:hexane:acetic acid as eluent to give 0.65 g (37%) of 4-carboxy-2-oxindole as a white solid.

1. concentrationThe mixture was concentrated to dryness, 20 mL ethanol and 1.1 g of tin(II) chloride
2. additionwere added
3. temperaturethe mixture was refluxed for 2 hours
4. filtrationThe mixture was filtered through Celite
5. concentrationconcentrated
6. customchromatographed on silica gel