METHODS OF FORMING 4-CHLORO-2-FLUORO-3-SUBSTITUTED-PHENYLBORONIC ACID PINACOL ESTERS AND METHODS OF USING THE SAME

摘要

Methods include formation of 4-chloro-2-fluoro-3-substituted-phenylboronic acid pinacol esters. The method comprises contacting a 1-chloro-3-fluoro-2-substituted benzene with an alkyl lithium to form a lithiated 1-chloro-3-fluoro-2-substituted benzene. The lithiated 1-chloro-3-fluoro-2-substituted benzene is contacted with an electrophilic boronic acid derivative to form a 4-chloro-2-fluoro-3-substituted-phenylboronate. The 4-chloro-2-fluoro-3-substituted-phenylboronate is reacted with an aqueous base to form a (4-chloro-2-fluoro-3-substituted-phenyl)trihydroxyborate. The (4-chloro-2-fluoro-3-substituted-phenyl)trihydroxyborate is reacted with an acid to form a 4 chloro-2-fluoro-3-substituted-phenylboronic acid. The 4-chloro-2-fluoro-3-substituted-phenylboronic acid is reacted with 2,3-dimethyl-2,3-butanediol to form 4-chloro-2-fluoro-3-substituted-phenylboronic acid pinacol esters. Methods of using 4-chloro-2-fluoro-3-substituted-phenylboronic acid pinacol esters to produce 6-(4-chloro-2-fluoro-3-substituted-phenyl)-4-aminopicolinates are also disclosed.