Acetic Anhydride → 1-[2-(Propan-2-yl)pyrazolo[1,5-a]pyridin-3-yl]ethan-1-one

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Reaction Steps

A mixture of 4.2g of 2-isopropylpyrazolo[1,5-a]pyridine, 10.2g of acetic anhydride and 2-3 drops of concentrated sulfuric acid was refluxed for 7 hr. After cooling, the mixture was added to 200 ml of 4M potassium hydroxide solution and stirred for 1 hr. The solution was extracted with chloroform and the chloroform solution was dried over sodium sulfate. The dried chloroform solution was concentrated and the residue was column-chromatographed over alumina to isolate objective product. Recrystallization from n-hexane gave 4.3g of colorless needles, mp 74° C. Yield 67%.

Provenance & Evidence