Acetic Acid → HCID 12202680, compound

Participants

Reaction Steps

A mixture of 3 g of 5-oxo-5H-[1]benzopyrano[2,3-b]pyridine-7-carbonitrile, 30 ml of sulfuric acid, 30 ml of acetic acid and 30 ml of water is heated under reflux for 3 hours. The reaction mixture is poured on ice, and adjusted to pH 3 by addition of 10% sodium hydroxide. The crystalline precipitate is filtered off and recrystallized from a mixture of dioxane and dimethylformamide to give 1.5 g of 5-oxo-5H-[1]benzopyrano[2,3-b]pyridine-7-carboxylic acid melting at 293°-294°C.

Provenance & Evidence