Hydrochloric Acid → (4-Chloro-3-((4-methoxybenzyl)oxy)phenyl)boronic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 145 g (387 mmol) of 2-[(4-methoxybenzyl)oxy]-1-chloro-4-iodobenzene in 1.2 L of anhydrous THF, placed under argon and stirred at −50° C., are added dropwise 220 mL (440 mmol) of a 2N solution of iPrMgCl in THF, while maintaining the temperature between −40 and −50° C. The reaction mixture is allowed to warm to −10° C. and stirring is continued for 1 hour. 94 mL (406 mmol) of triisopropyl borate are then added and the reaction mixture is then allowed to warm slowly to 0° C. After stirring for 2 hours, the mixture is treated with 500 mL of aqueous 5N HCl solution and then extracted with ether (2×600 mL). The organic phase is washed with 2×1 L of water, dried over Na2SO4 and then concentrated under reduced pressure. The residue obtained is solidified in 300 mL of pentane, filtered off on a sinter funnel and washed with 200 mL of pentane. 96 g of [3-[(4-methoxybenzyl)oxy]-4-chlorophenyl]boronic acid are thus obtained in the form of a white solid.

Provenance & Evidence