Sodium hydride (60% dispersion in mineral oil) (0.682 g, 17.05 mmol) was added to (S)-3-(3-(tert-butyldimethylsilyloxy)azetidin-1-yl)-N-(5-fluoropyridin-2-yl)-2-hydroxypropanamide (Intermediate AX2) (3.0 g, 8.12 mmol) in anhydrous THF (80 mL) at 0° C. under nitrogen. The resulting solution was stirred at 0° C. for 10 minutes and then 4-chloro-1-(2-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidine (Intermediate B1) (2.63 g, 8.93 mmol) was added. The reaction mixture was allowed to warm to room temperature and stirred for 3 hours. The reaction mixture was neutralised with 1M citric acid and then diluted with water (50 mL) and EtOAc (100 mL). The organic layer was separated and the aqueous layer re-extracted with EtOAc (100 mL). The combined organics were washed with saturated brine (75 mL),dried (MgSO4), filtered and concentrated in vacuo. The crude product was purified by flash silica chromatography, elution gradient 30 to 70% EtOAc in isohexane to afford the product (4.29 g, 88%). 1H NMR (400 MHz, CDCl3) δ 0.04 (6H, s), 0.88 (9H, s), 3.06-3.10 (2H, m), 3.15-3.19 (1H, m), 3.27-3.31 (1H, m), 3.87-3.90 (2H, m), 4.41-4.48 (1H, m), 5.89-5.92 (1H, m), 7.40-7.55 (4H, m), 7.61-7.63 (1H, m), 8.15 (1H, d), 8.22-8.26 (1H, m), 8.36 (1H, s), 8.59 (1H, s), 9.82 (1H, s); m/z (ES+) (M+H)+=598; HPLC tR=2.82 min.
