Acetic Acid → 2-oxo-2,3-dihydro-1H-indole-4-carboxylic acid

Participants

Reaction Steps

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 (11) chloride in 20 mL of ethanol. The mixture was filtered through Celite, concentrated and chromatographed on silica gel in ethyl acetate:hexane;acetic acid to give 0.65 g (37% yield) of 4-carboxy-2-oxindole as a while solid.

Provenance & Evidence