Sodium Carbonate → 4-[4-(4-Ethoxy-2-fluoro-phenoxy)-pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-ethoxy-2-fluoro-phenol (Intermediate 5; 125 mg, 0.801 mmol), 4-(4-chloro-pyrazolo[3,4-d]pyrimidin-1-yl)-piperidine-1-carboxylic acid tert-butyl ester (Intermediate 19; 270 mg, 0.801 mmol), and potassium carbonate (244 mg, 1.761 mmol) in 4 mL of dimethylformamide was heated in a microwave oven at 160° C. for 10 min. Saturated sodium carbonate solution was added to the reaction mixture, the precipitate was filtered and the filtrate was extracted with ethyl acetate three times and the combined organic extracts were washed with saturated brine, and dried over sodium sulfate. The mixture was filtered, concentrated and purified by flash silica gel chromatography (4% methanol in dichloromethane) to afford 4-[4-(4-ethoxy-2-fluoro-phenoxy)-pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid tert-butyl ester (141 mg, 39%) as a white solid. Mass spectrum M+H-Boc=358.

Provenance & Evidence