6-(3-Methoxyphenyl)-1,3-dihydroindol-2-one → 4-(2-Carboxyethyl)-5-[6-(3-methoxyphenyl)-2-oxo-1,2-dihydroindol-3-ylidenemethyl]-3-methyl-1H-pyrrole-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

5-Formyl-4-(2-ethoxycarbonylethyl)-3-methyl-1H-pyrrole-2-carboxylic acid ethyl ester (281 mg), 6-(3-methoxy-phenyl)-2-oxindole (287 mg), and piperidine (2 drops) in ethanol (5 mL) were stirred at 90° C. overnight. The precipitate was filtered and washed with ethanol. The yellow orange solid and potassium hydroxide (4 pellets) were stirred in ethanol (3 mL) at 90° C. for 2.5 hours. The reaction mixture was cooled and concentrated. The residue was dissolved into water and acidified with 2 N hydrochloric acid to pH 2. The precipitate was filtered, washed with water, and dried in a vacuum oven overnight to give 413 mg of 4-(2-Carboxyethyl)-5-[6-(3-methoxyphenyl)-2-oxo-1,2-dihydroindol-3-ylidenemethyl]-3-methyl-1H-pyrrole-2-carboxylic acid.

Provenance & Evidence