1220968-24-0

The reaction was carried out in the presence of cesium carbonate (1.5 g, 4.6 mmol) in acetonitrile (8 mL) at 90 °C with stirring for 4 h. The reaction was carried out in the presence of cesium carbonate (1.5 g, 4.6 mmol) at 90 °C for 4 h. The reaction was completed by cooling to room temperature and quenching the reaction with aqueous Na2CO3. After completion of the reaction, the reaction was cooled to room temperature, quenched with aqueous Na2CO3, extracted with ethyl acetate (3 × 20 mL), and the organic phases were combined and washed with brine. The organic layer was dried over anhydrous MgSO4, filtered and concentrated under reduced pressure. The crude product was purified by fast chromatography on a silica gel column eluting with gradient of ethyl acetate/hexane (0-50%) to afford the target compound ethyl 2-(4-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)propionate (0.42 g, 61% yield).LCMS (M+H)+: m/z=295.1.

[1] Patent: US2012/165305, 2012, A1. Location in patent: Page/Page column 43
[2] Patent: US2014/296316, 2014, A1. Location in patent: Paragraph 0193; 0194; 0195