Hydrochloric Acid → 1-(4-Fluorophenyl)-1H-pyrazolo[3,4-c]pyridine-4-carboxylic acid

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Reaction Steps

A mixture of 1-(4-fluorophenyl)-1H-pyrazolo[3,4-c]pyridine-4-carboxylic acid ethyl ester (2.75 g, 9.64 mmol) and 85% potassium hydroxide pellets (6.4 g, 84 mmol) in methanol-water was warmed at reflux for 15 minutes and then stirred overnight. The mixture was then diluted with water (300 mL) and then a dilute solution of aqueous HCl (1 equivalent based on mass of KOH) was added in several portions (final pH=5). The resulting solid was collected by filtration and dried by pulling vacuum through the filter cake to afford 1-(4-fluorophenyl)-1H-pyrazolo[3,4-c]pyridine-4-carboxylic acid.

Provenance & Evidence