preparation | 2-bromo-1-fluoro-4-nitrobenzene (13.2g,60mmol),4,4,4 ',4',5,5 ',5',5 '-octamethyl -2,2'-union (1,3,2-dioxboropentane)(22.8g,90mmol),[1,1 '-bis (diphenylphosphine) ferrocene] palladium dichloride (880mg,12mmol), potassium acetate (17.6g,180mmol) dissolved in 1,4-dioxane (180mL), replaced nitrogen, heated to 90 ℃ and stirred overnight, LC/MS detection reaction was complete. Water (150mL) was added to the reaction solution, extracted with ethyl acetate (200mL), the organic phase was washed with saturated salt water (150mL * 2), dried with anhydrous sodium sulfate, concentrated and purified with silica gel preparation chromatography (petroleum ether: ethyl acetate = 10:1) to obtain 2-fluoro-5-nitrophenylborate pinacyl ester (14.0g, yield 87.3%). |