Synthesis
Under argon protection, 4-bromobenzonitrile 91.1 g (0.5 mol), sodium acetate 98.4 g (1.2 mol), diethylene glycol dimethyl ether 800 mL and bis(pinacolato)diboron 152.4 g (0.6 mol) were added sequentially, the reaction temperature was controlled at 140 C, and catalyst 1,1'-bis(dicyclohexylphosphino)ferrocene palladium chloride 375.5 mg was added (0.5 mmol), the reaction was detected by high performance liquid chromatography (HPLC) after 14 h. The reaction was quenched with 600 mL of water, extracted with 300 mL of toluene for 3 times, the organic phases were combined, dried with anhydrous magnesium sulfate, filtered, and the solvent was recovered by decompression to obtain a brown solid, which was distilled using a 4L oil pump to obtain 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolato) benzonitrile 111.4 g. Content 99.5% (GC), yield 97.2%, melting point 93.6-94.5 .