Tetrabutylammonium Fluoride → (2S)-N-(5-chloropyridin-2-yl)-2-(1-(5-fluoro-2-methylphenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-3-(2-hydroxyethoxy)propanamide

Participants

Reaction Steps

Tetrabutylammonium fluoride (1M in THF) (0.538 mL, 0.54 mmol) was added to (2S)-3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-N-(5-chloropyridin-2-yl)-2-(1-(5-fluoro-2-methylphenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)propanamide (Intermediate AK5) (390 mg, 0.54 mmol) in THF (5 mL) under nitrogen. The resulting mixture was stirred at ambient temperature for 1 hour. The reaction mixture was quenched with saturated NH4Cl (2 mL), diluted with DCM (25 mL) and poured onto a phase separator. The organic phase was evaporated to give the crude product. This was purified by preparative HPLC (Waters XBridge Prep C18 OBD column, 5μ silica, 50 mm diameter, 150 mm length), using decreasingly polar mixtures of water (containing 0.1% formic acid) and MeCN as eluents to afford the product (136 mg, 51.9%, 75% ee). 1H NMR (400 MHz, DMSO) δ 1.88 (3H, s), 3.35 (2H, m), 3.43 (2H, m), 3.84 (1H, dd), 3.92 (1H, dd), 4.47 (1H, t), 5.74 (1H, m), 7.19 (2H, m), 7.36-7.29 (1H, m), 7.71 (1H, dd), 7.83 (1H, d), 8.23 (1H, d), 8.37 (1H, s), 8.43 (1H, s), 11.05 (1H, s). m/z (ES+) (M+H)+=487; HPLC tR=2.28 min.

Provenance & Evidence