Citric Acid → (3S)-3-(1-(3-chloropyridin-2-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)dihydrofuran-2(3H)-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

60% Sodium hydride in mineral oil (0.470 g, 11.75 mmol) was added to (S)-3-hydroxydihydrofuran-2(3H)-one (0.764 mL, 9.80 mmol) in anhydrous THF (30 mL) at 0° C. under nitrogen. The resulting solution was stirred at 0° C. for 10 minutes and then 4-chloro-1-(3-chloropyridin-2-yl)-1H-pyrazolo[3,4-d]pyrimidine (CAS no. 52079-23-9) (2.87 g, 10.77 mmol) was added portionwise maintaining the temperature below 5° C. The reaction mixture was allowed to warm to room temperature and stirred for 1 hour. The reaction mixture was neutralised with 1M citric acid and the majority of the THF removed in vacuo. The reaction mixture diluted with water (20 mL) and ethyl acetate (50 mL). The organic layer was separated and the aqueous layer re-extracted with ethyl acetate (2×100 mL). The combined organics were washed with saturated brine (75 mL), water (75 mL) dried (MgSO4), filtered and evaporated. The residue was purified by flash silica chromatography, eluting with 50 to 100% ethyl acetate in isohexane to afford the product (1.970 g, 61%). 1H NMR (400 MHz, CDCl3) 2.52-2.62 (1H, m), 2.92-3.00 (1H, m), 4.41-4.47 (1H, m), 4.59-4.64 (1H, m), 6.11-6.16 (1H, m), 7.46-7.49 (1H, m), 8.00-8.02 (1H, m), 8.37 (1H, s), 8.61-8.63 (1H, m), 8.64 (1H, s); m/z (ESI+) (M+H)+=332; HPLC tR=1.51 min.

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