Synthesis
Under nitrogen protection, 4-(4-propylcyclohexyl)iodobenzene (50.0 g) was added to a reaction vial with anhydrous ether (800 mL) and cooled to -70 °C. Slowly n-butyllithium (1.63 M, n-hexane solution, 112 mL) was added dropwise, and after completion of the dropwise addition, the reaction was stirred at -70 °C for 2 hours. Subsequently, a solution of diethyl ether (50.0 mL) of trimethyl borate (22.8 g) was slowly added, gradually warmed to room temperature and continued stirring for 12 hours. Upon completion of the reaction, the reaction solution was cooled to -30°C, 6N hydrochloric acid (150 mL) was slowly added, gradually warmed to room temperature and stirred for 3 hours. The reaction mixture was poured into water and the aqueous layer was extracted with ethyl acetate. The organic layers were combined, washed with saturated brine and dried over anhydrous magnesium sulfate. The organic phase was concentrated under reduced pressure and the residue was purified by recrystallization from heptane to give (4-(4-propylcyclohexyl)phenyl)boronic acid (29.2 g, 78% yield).
