4-Nitrophenylboronic acid → tert-butyl 4-(4-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)-6-(4-nitrophenyl)-1H-pyrazolo[3,4-d]pyrimidin-1-yl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of tert-butyl 4-(4-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)-6-chloro-1H-pyrazolo[3,4-d]pyrimidin-1-yl)piperidine-1-carboxylate (2.9 mmol), 4-nitrophenylboronic acid (0.73 g, 4.4 mmol), and tetrakis(triphenylphosphine)palladium(0) (0.34 g, 10 mol %) in toluene/ethanol (1:1, 12 mL) and 2 M aqueous sodium carbonate solution (3 mL) was heated in a 10-20 mL Smith process vial in the microwave reactor for one hour at 120° C. The cooled mixture was partitioned between ethyl acetate and water. The aqueous phase was extracted three times with ethyl acetate. The combined extracts were washed twice with 1 M aqueous sodium hydroxide solution, once with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, filtered, and concentrated to dryness under reduced pressure. The crude residue was further purified by automated flash chromatography (methanol/dichloromethane) to provide tert-butyl 4-(4-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)-6-(4-nitrophenyl)-1H-pyrazolo[3,4-d]pyrimidin-1-yl)piperidine-1-carboxylate. MS (ES+): 536.3 (M+H)+

Provenance & Evidence