4-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)BENZONITRILE

light yellow to orange or light tan crystalline powde

4-(Cyanophenyl)boronic Acid Pinacol Ester is used to prepare arylparacyclophanes via Suzuki aryl cross-coupling of bromoparacyclophane with arylboronic acid and arylboronates. It’s also used to prepare tyrosine-modified analogs of α4β7 integrin inhibitor biotin-R8ERY.

The Journal of Organic Chemistry, 60, p. 7508, 1995 DOI: 10.1021/jo00128a024

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 .