2-Amino-5-chloropyridine → (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

Participants

Reaction Conditions

Reaction Steps

Trimethylaluminium (2M in toluene) (0.556 mL, 1.11 mmol) was added dropwise to a stirred solution of 5-chloropyridin-2-amine (143 mg, 1.11 mmol) in toluene (10 mL), under nitrogen at 0° C. The resulting solution was allowed to stir at this temperature for a further 20 minutes. (2S)-methyl 3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-2-(1-(5-fluoro-2-methylphenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)propanoate (Intermediate AK4) (466 mg, 0.74 mmol) in toluene (5 mL) was added slowly to the mixture at 0° C. The reaction mixture was then heated to 100° C. and was stirred for 6 hours using the microwave. The reaction mixture was allowed to cool to ambient temperature, then evaporated to afford a gum. This was dissolved in EtOAc (75 mL), and washed sequentially with Rochelle's solution (20 mL), and water (20 mL). The organic layer was dried (MgSO4), filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 10 to 30% EtOAc in isohexane to afford the product (390 mg, 72.6%). 1H NMR (400 MHz, DMSO) δ 0.88 (9H, s), 2.03 (3H, s), 3.82-3.67 (4H, m), 4.05 (1H, m), 4.15 (1H, m), 6.00 (1H, m), 7.45-7.31 (8H, m), 7.50 (1H, t), 7.60 (4H, m), 7.87 (1H, dd), 8.02 (1H, d), 8.40 (1H, d), 8.51 (1H, s), 8.56 (1H, s), 11.25 (1H, s); m/z (ES+) (M+H)+=725; HPLC tR=3.63 min.

Provenance & Evidence