Lithium Hexamethyldisilazide → (2S)-2-[1-(3-chloropyridin-2-yl)pyrazolo[4,5-e]pyrimidin-4-yl]oxy-3-ethoxy-N-(5-methylpyrazin-2-yl)propanamide

Participants

Reaction Steps

A solution of lithium bis(trimethylsilyl)amide (1.40 mL, 1.40 mmol) was added dropwise to a stirred solution of (S)-3-ethoxy-2-hydroxy-N-(5-methylpyrazin-2-yl)propanamide (Intermediate H1) (315 mg, 1.40 mmol) in THF (15 mL) over a period of 3 minutes under nitrogen. The resulting suspension was stirred at ambient temperature for 10 minutes and then a solution of 4-chloro-1-(3-chloropyridin-2-yl)-1H-pyrazolo[3,4-d]pyrimidine (Intermediate B15) (372 mg, 1.40 mmol) in anhydrous THF (3 mL) added dropwise over 1 minute and the reaction heated to 50° C. for 3 hours. The reaction mixture was diluted with EtOAc (50 mL), and washed sequentially with water (2×25 mL) and saturated brine (25 mL). The organic layer was dried (MgSO4) and evaporated. The residue was purified by flash silica chromatography eluting with EtOAc to afford (2S)-2-[1-(3-chloropyridin-2-yl)pyrazolo[4,5-e]pyrimidin-4-yl]oxy-3-ethoxy-N-(5-methylpyrazin-2-yl)propanamide (330 mg, 52%). 1H NMR (400 MHz, CDCl3) δ 1.24 (3H, t), 2.54 (3H, s), 3.60-3.68 (2H, m), 4.07-4.16 (2H, m), 6.09 (1H, t), 7.47 (1H, dd), 8.01 (1H, dd), 8.12 (1H, d), 8.47 (1H, s), 8.62 (1H, dd), 8.64 (1H, s), 8.66 (1H, s), 9.44 (1H, d); m/z (ESI+) (M+H)+=455; HPLC tR=1.77 min.

Provenance & Evidence