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

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Reaction Steps

Cyclopentyl chloroformate (12 mg, 0.078 mmol) 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), diisopropylethylamine (30 mg, 0.235 mmol) in dichloromethane (2 mL). The reaction 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-fluorophenoxy)-pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid cyclopentyl ester (36 mg, 99%) as a white solid. Mass spectrum MH+=470.

Provenance & Evidence