1000801-76-2

1183903-41-4

73183-34-3

1000801-76-2

Potassium acetate (2.4 g, 24 mmol) and Pd(dppf)Cl2 (900 mg, 1.22 mmol) were sequentially added in DMSO (20 mL) as 4-bromo-1-(3-methoxypropyl)-1H-pyrazole (2.1 g, 9.6 mmol) and pinacol ester of bisboronic acid (3.7 g, 15 mmol). The reaction mixture was stirred at 100 °C for 13 h under nitrogen protection. After completion of the reaction, it was cooled to room temperature and the reaction was quenched with saturated aqueous NaCl solution (30 mL). The mixture was extracted with dichloromethane (30 mL x 3), the organic layers were combined and dried with anhydrous Na2SO4. After concentration under reduced pressure, the residue was purified by silica gel column chromatography with the eluent of petroleum ether/ethyl acetate (2:1, v/v) to afford the light yellow oily target product 1-(3-methoxypropyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.3 g, 51% yield). Mass spectrum (ESI, positive ion mode) m/z: 267.0 [M + 1]+.