Water → 4-[4-(4-Ethoxy-2-fluoro-phenoxy)pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid isopropyl ester

Participants

Reaction Steps

Isopropyl chloroformate (Aldrich Chemical Company, Inc., Milwaukee, Wis., USA; 1 M in toluene; 0.079 ml, 0.079 mol) was added to a mixture of 4-(4-ethoxy-2-fluoro-phenoxy)-1-piperidin-4-yl-1H-pyrazolo[3,4-d]pyrimidine trifluoroacetate salt (Intermediate 29; 28 mg, 0.078 mmol), and diisopropylethylamine (30 mg, 0.235 mmol) in dichloromethane (2 mL). The reaction mixture was stirred at room temperature overnight. Water was added to quench the reaction and the aqueous layer was extracted three times with dichloromethane. The combined organic layers were dried (sodium sulfate), filtered, evaporated and purified by flash chromatography on silica gel, eluting with 4% methanol/dichloromethane to give 4-[4-(4-ethoxy-2-fluoro-phenoxy)pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid isopropyl ester (27 mg, 80%) as a white solid. Mass spectrum MH+=444.

Provenance & Evidence