Sulfuric Acid → HCID 12281154, compound

Participants

Reaction Steps

87 g. of 5-benzoyl-4-ethoxy-1-(2-furanyl)methyl-1H-pyrazolo[3,4-b]pyridine (0.25 mol.) are dissolved in 300 ml. of conc. sulfuric acid within 15 to 20 minutes with vigorous stirring. The temperature rises to 40°-45°. Stirring is continued for 1 hour. The dark colored mixture is then added to 3700 ml. of cold water. Stirring is continued for 2 hours and the dark by-products are filtered off. The filtrate is made alkaline with 25% aqueous ammonia. The white precipitate of 5-benzoyl-4-ethoxy-1H-pyrazolo[3,4-b]pyridine is filtered off, yield 44.8 g. (66%), m.p. 202°-203° (butanol).

Provenance & Evidence