Into a 100 mL, 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed a solution of tert-butyl (3R)-3-[4-amino-3-iodo-1H-pyrazolo[3,4-d]pyrimidin-1-yl]piperidine-1-carboxylate (300 mg, 0.68 mmol, 1.00 equiv) in dioxane/H2O(7/3=V/V) (30 mL), [4-(2-fluorophenoxy)phenyl]boronic acid (500 mg, 2.16 mmol, 6.99 equiv), sodium carbonate (200 mg, 1.89 mmol, 0.26 equiv), and Pd(PPh3)4 (500 mg, 0.43 mmol, 3.19 equiv). The resulting solution was stirred overnight at 100° C. in an oil bath an then concentrated under vacuum. The residue was loaded onto a silica gel column and eluted with dichloromethane/methanol (100:1) to give 0.2 g (59%) of tert-butyl (3R)-3-[4-amino-3-[4-(2-fluorophenoxy)phenyl]-1H-pyrazolo[3,4-d]pyrimidin-1-yl]piperidine-1-carboxylate as a light yellow solid.
