Acetic Acid → 3-Ethoxy-4-phenyl-4H-furo[3,2-b]indole-2-carboxylic acid

Participants

Reaction Steps

A suspension of 12.0 g (0.036 mole) of 3-ethoxy-4-phenyl-4H-furo[3,2-b]indole-2-carboxylic acid methyl ester in 100 ml of methanol was treated with 60 ml of 1.0N aqueous sodium hydroxide. After stirring at reflux for 20 hours, the cooled reaction mixture was added to 1.2 kg ice/water, and the mixture was acidified with acetic acid. The crude product was filtered, stirred in 600 ml water, and refiltered. Recrystallization from ethanol yielded 5.1 g of analytically pure acid containing 0.35 mole of water of hydration, mp 146°-147° C. An additional 1.8 g of product was obtained from the recrystallization filtrate, for a total yield of 6.9 g (59% yield).

Provenance & Evidence