反应详情

2-Phenylpyrazolo[1,5-a]pyridine (2.00 g) was added to a stirred solution of acetic anhydride (4.20 g) and two drops of sulfuric acid at room temperature. After being stirred under reflux for 14 hours, the reaction mixture was poured onto 80 ml of 4N NaOH aqueous solution and extracted with chloroform (30 ml×2). The extracts were combined and washed with water (30 ml), saturated sodium chloride aqueous solution (30 ml), then dried over magnesium sulfate and evaporated in vacuo. The residual crystals were recrystallized from diisopropyl ether to give 2-phenyl-3-acetylpyrazolo-[1,5-a]pyridine (1.16 g).

1. temperatureunder reflux for 14 hours
2. extractionextracted with chloroform (30 ml×2)
3. washwashed with water (30 ml), saturated sodium chloride aqueous solution (30 ml)
4. dry with materialdried over magnesium sulfate
5. customevaporated in vacuo
6. customThe residual crystals were recrystallized from diisopropyl ether