Triethylamine → 1-(4-fluorophenyl)-1H-pyrazolo[3,4-c]pyridine-4-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-bromo-1-(4-fluorophenyl)-1H-pyrazolo[3,4-c]pyridine (3.5 g, 12 mmol), Et3N (3.5 mL, 25 mmol), Pd[PhCN]2Cl2 (105 mg, 0.273 mmol), and dppf (418 mg, 0.754 mmol) in absolute ethanol (90 mL) was placed in a sealed bomb with stifling and placed under 15 bars of carbon monoxide and warmed to 140° C. for 4 hours. The mixture was then cooled to room temperature, returned to atmospheric pressure and opened. The reaction was monitored by TLC (EtOAc-hexanes 4:6 and EtOAc) indicating the starting material was consumed. The reaction was diluted with water (300 mL) and the solid was collected by filtration washing with water. The filtrate was diluted with water (200 mL) and extracted with EtOAc (2×100 mL). The combined organic layers were washed with brine (2×100 mL). The still moist filter cake was dissolved in EtOAc and combined with the extracted organic layers, dried over magnesium sulfate, treated with activated carbon) and filtered through a pad of diatomaceous earth and a layer of silica gel. The material from the pad was dissolved in dichloromethane and passed through a pad of silica gel eluting with dichloromethane to afford 1-(4-fluorophenyl)-1H-pyrazolo[3,4-c]pyridine-4-carboxylic acid ethyl ester.

Provenance & Evidence