Synthesis
4-Bromodiphenyl ether (100 g, 0.402 mol)Was dissolved in anhydrous THF (800 mL)Under nitrogen protection,Cooled to -78 ° C,N-butyllithium (n-BuLi) (177 mL, 0.442 mol)The temperature is kept below -65 ° C,After stirring for 1 h,Continue to maintain the temperature -60 ,Triisopropyl borate (90 g, 0.482 mol) was added dropwise,Slowly rose to 0 ° C, stir for 3 h.Water (300 mL) was added under ice bath overnight. The reaction solution was concentrated to remove the organic phase,With 12N concentrated hydrochloric acid pH adjusted to 1 ~ 2,Precipitation of solids,Filtration and drying gave 4-phenoxyphenylboronic acid (77 g, yield 90%).
