Sodium Hydroxide → HCID 12790120, compound

Participants

Reaction Steps

4.8 g of bromine is added dropwise to a solution of 3.3 g of sodium hydroxide in 28 ml of water at below 0°C, and the mixture is allowed to stand at 0°C for 15 minutes. To the mixture is added dropwise and slowly a solution of 2.4 g of 7-acetyl-5,5-dimethyl-5H-[1]benzopyrano[2,3-b]pyridine in 10 ml of dioxane. The whole mixture is allowed to stand at room temperature for 2 hours, and then the solvent is removed by distillation under reduced pressure. To the residue are added water and benzene, and the mixture is warmed to 30°-40°C. The aqueous layer is neutralized with hydrochloric acid. The crystalline precipitate is recrystallized from aqueous acetic acid to give 1.9 g of 5,5-dimethyl-5H-[1]benzopyrano[2,3-b]pyridine-7-carboxylic acid melting at 241°-242°C.

Provenance & Evidence