To a solution of 1-[(1-(3-azetidin-3-yl-5-chloro-2-methoxy-4-methylphenyl)ethyl]-3-methyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine dihydrochloride (10 mg, 0.022 mmol, chiral intermediate from Example 1, Step 7) in acetonitrile (0.1 mL) was added cyclobutylideneacetonitrile (4.1 mg, 0.044 mmol), followed by 1,8-diazabicyclo[5.4.0]undec-7-ene (13 μL, 0.087 mmol). The resulting mixture was stirred at room temperature overnight. The reaction mixture was diluted with acetonitrile and purified by preparative RP-HPLC (XBridge C18 column, eluting with a gradient of acetonitrile/water containing 0.1% ammonium hydroxide, at flow rate of 30 mL/min) to give the desired product (4.3 mg, 41%). The product was isolated as a single enantiomer. LCMS calculated for C25H31ClN7O (M+H)+: m/z=480.2; Found: 480.0.
