Hydrochloric Acid → 4,6-Bis(4-fluorophenyl)-5-(4-pyridyl)-1H-pyrazolo[3,4-b]pyridine

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Reaction Steps

In a volumetric flask, 1-(4-fluorophenyl)-2-(4-pyridyl)ethanone (23.56 g, 109.4 mmol, obtained in reference example 1) and 2-methoxyethanol (150 mL) were introduced. A solution of 3-amino-2H-pyrazole (10.00 g, 120.3 mmol) in 2-methoxyethanol (170 mL) and 37% HCl (3.23 g, 32.8 mmol) were added under argon atmosphere. This was heated to reflux for 3 days. It was allowed to cool and concentrated. The solid obtained was dissolved in CHCl3 (400 mL) and MeOH (50 mL) and washed with 0.1 N HCl (300 mL) and 1 N NaOH (300 mL). The organic phase was dried over Na2SO4 and concentrated to dryness, to afford 9.93 g of the desired product in solid cream form (yield: 47%)

Provenance & Evidence