650 mg (1.7 mmol) of 3-(6-chloro-1-(piperidin-4-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl)-8-oxa-3-azabicyclo[3.2.1]octane was suspended in 15 mL dichloromethane and triethylamine (0.5 mL) was added followed by addition of a 1N solution of isopropyl chloroformate in toluene. The mixture was stirred at room temperature overnight, diluted with dichloromethane and washed with sat. aqueous NaHCO3. The organic phase was dried over MgSO4, filtered and concentrated to give 696 mg (1.6 mmol) of the title compound. MS: 435.3/437.3 [M+H].
