Hydrochloric Acid → 3-[2-(6-methoxy-2-oxo-1,2-dihydro-indol-3-ylidenemethyl)-4-methyl-1H-pyrrol-3-yl]-propionic acid

Participants

Reaction Conditions

Reaction Steps

4-(2-carboxyethyl)-3-methyl-5-(6-methoxy-2-oxo-1,2-dihydroindol-3-ylidenemethyl)-1H-pyrrole-2-carboxylic acid (501 mg) suspended in ethylene glycol (10 mL) was heated in a sealed tube in a pre-heated oil bath at 200° C. for 2 hours. The reaction mixture was cooled to 90° C. and potassium hydroxide (2 pellets) was added. The mixture was then stirred at 90° C. for 30 minutes, after which time it was cooled, poured 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 221 mg (48%) of 3-[2-(6-methoxy-2-oxo-1,2-dihydro-indol-3-ylidenemethyl)-4-methyl-1H-pyrrol-3-yl]-propionic acid.

Provenance & Evidence