Abstract: Methods of isolating a 4-chloro-2-fluoro-3-substituted-phenylboronate include adding carbon dioxide gas or carbon dioxide solid (dry ice) to a solution comprising a 4-chloro-2-fluoro-3-substituted-phenylboronate, an inert organic solvent, and at least one lithium salt to react the at least one lithium salt with the carbon dioxide gas or carbon dioxide solid (dry ice) and form a mixture comprising the 4-chloro-2-fluoro-3-substituted-phenylboronate, the inert organic solvent, and a precipitated solid. The precipitated solid may be removed from the mixture. Methods of using 4-chloro-2-fluoro-3-substituted-phenylboronates to produce methyl-4-amino-3-chloro-6-(4-chloro-2-fluoro-3-substituted-phenyl)pyridine-2-carboxylates are also disclosed.

Abstract: Methods for the selective borylation of arenes, including arenes substituted with an electron-withdrawing group (e.g., 1-chloro-3-fluoro-2-substituted benzenes) are provided. The methods can be used, in some embodiments, to efficiently and regioselectively prepare borylated arenes without the need for expensive cryogenic reaction conditions.

Abstract: 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.

Abstract: Provided herein are methods of isolating a 4-chloro-2-fluoro-3-substituted-phenylboronic acid. The method comprises contacting a mixture of water, a water-miscible organic solvent, and a 4-chloro-2-fluoro-3-substituted-phenylboronic acid with a salt to form a water-miscible organic solvent layer and a water layer. The 4-chloro-2-fluoro-3-substituted-phenylboronic acid is partitioned into the water-miscible organic solvent layer, which is separated from the water layer. Additional methods are disclosed, as is a 4-chloro-2-fluoro-3-substituted-phenylboronic acid produced by one of the methods, wherein the 4-chloro-2-fluoro-3-substituted-phenylboronic acid is obtained at a yield of greater than approximately 90%.

Abstract: Residual palladium is removed and recovered from 4-amino-3-halo-5-fluoro-6-(aryl)pyridine-2-carboxylates and 4-amino-3-halo-6-(aryl)pyridine-2-carboxylates by treatment with an aqueous solution containing from about 20 to about 50% of an alkali metal bisulfite at a temperature from about 60 to about 90° C. and a pH from about 3.8 to about 7.0.

Abstract: Methods of producing methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate. One method comprises adding methyl isobutyl ketone to an aqueous solution comprising 4-chloro-2-fluoro-3-methoxyphenyl-boronic acid to form an organic phase comprising the 4-chloro-2-fluoro-3-methoxyphenylboronic acid and an aqueous phase. The organic phase and the aqueous phase are separated. The 4-chloro-2-fluoro-3-methoxyphenylboronic acid is reacted with methyl 4-(acetylamino)-3,6-dichloropyridine-2-carboxylate in methyl isobutyl ketone to produce methyl 4-(acetylamino)-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate, which is deacetylated to produce methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate.

Abstract: Provided herein are methods of isolating a 4-chloro-2-fluoro-3-substituted-phenylboronic acid. The method comprises contacting a mixture of water, a water miscible organic solvent, and a 4-chloro-2-fluoro-3-substituted-phenylboronic acid with a salt to form a water miscible organic solvent layer and a water layer. The 4-chloro-2-fluoro-3-substituted-phenylboronic acid is partitioned into the water miscible organic solvent layer, which is separated from the water layer. Additional methods are disclosed, as is a 4-chloro-2-fluoro-3-substituted-phenylboronic acid produced by one of the methods, wherein the 4-chloro-2-fluoro-3-substituted-phenylboronic acid is obtained at a yield of greater than approximately 90%.

Abstract: 1-Fluoro-2-substituted-3-chlorobenzenes are selectively deprotonated and functionalized in the position adjacent to the fluoro substituent.

Abstract: 1-Fluoro-2-substituted-3-chlorobenzenes are selectively deprotonated and functionalized in the position adjacent to the fluoro substituent.