2-Benzyloxyphenylboronic acid

31575-75-4

190661-29-1

General procedure for the synthesis of 2-benzyloxyphenylboronic acid from 2-benzyloxybromobenzene: 1) 19.93 mL of BuLi (1.6 M hexane solution, 31.9 mM, 1 eq.) was slowly added to a 50 mL THF solution containing 8.4 g of 2-benzyloxybenzene bromide (31.9 mM, 1 eq.) via syringe at -78 °C. Stirring was continued at -78 °C for 30 min to obtain a THF solution of the lithiated derivative. 2) Through a dropping funnel, the above lithiated derivative solution was slowly added dropwise at -78°C to a 50 mL THF solution containing 30 g of B(OiPr)3 (159.5 mM, 5 eq.). 3) After the dropwise addition was completed, the reaction mixture was allowed to gradually warm up to room temperature and stirring was continued for 4 hours. 4) The reaction mixture was poured into 20 mL of 3N HCl to quench the reaction, extracted twice with 50 mL of EtOAc, the organic phases were combined, washed with water, dried over anhydrous MgSO4, and concentrated to dryness under reduced pressure to give 8.53 g of crude product. (5) The crude product was purified by silica gel column chromatography with 9:1 cyclohexane/EtOAc as eluent, and finally 3.6 g of pure product was obtained in 47% yield.