Sodium Bicarbonate → 3-(2-Oxo-1,2,5,6-tetrahydropyridin-4-yl)-2-phenylpyrazolo[1,5-a]pyridine

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Reaction Conditions

Reaction Steps

A mixture of 2-phenylpyrazolo[1,5-a]pyridine (0.50 g), 2,4-piperidinedione (0.292 g), concentrated sulfuric acid (1 drop) and acetic acid (0.5 ml) was heated at 135° C. for 13.5 hours. A saturated aqueous solution of sodium hydrogen carbonate (20 ml) was added to the reaction mixture and the mixture was extracted with chloroform (20 ml×2). The combined extract was washed with a saturated aqueous solution of sodium chloride (20 ml) and dried over magnesium sulfate. The solvent was evaporated in vacuo. The residue was purified by column chromatography on silica gel using a mixture of chloroform and ethyl acetate (9:1) and recrystallized from ethyl acetate to give crystals of 3-(2-oxo-1,2,5,6-tetrahydropyridin-4-yl)-2-phenylpyrazolo[1,5-a]pyridine.

Provenance & Evidence