Tetrabutylammonium Fluoride → (2S)-2-(1-(2-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-3-(2-hydroxyethoxy)-N-(pyridin-2-yl)propanamide

A solution of tetrabutylammonium fluoride (1M in THF) (0.984 mL, 0.98 mmol) was added in one portion to a stirred solution of (2S)-3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-2-(1-(2-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-N-(pyridin-2-yl)propanamide (Intermediate AQ5) (0.682 g, 0.98 mmol) in tetrahydrofuran (15 mL). The resulting solution was stirred at ambient temperature for 30 minutes. The reaction mixture was quenched with saturated NH4Cl (10 mL), and diluted with water (20 mL) and EtOAc (50 mL). The organic layer was separated and the aqueous layer extracted with EtOAc (50 mL), The combined organics were dried (MgSO4), filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 80 to 100% EtOAc in isohexane to afford the product (0.335 g, 74.9%). 1H NMR: (400 MHz, CDCl3) δ 2.91 (1H, s), 3.74-3.79 (4H, m), 4.15-4.25 (2H, m), 6.10 (1H, t), 7.06-7.10 (1H, m), 7.45-7.63 (4H, m), 7.71-7.75 (1H, m), 8.19 (1H, d), 8.27-8.29 (1H, m), 8.44 (1H, s), 8.60 (1H, s), 9.01 (1H, s); m/z (ES+) (M+H)+=455; HPLC tR=1.76 min.