Patent ID: 8754110

Claim:
A method of producing methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate, comprising: adding methyl isobutyl ketone to an aqueous solution comprising 4-chloro-2-fluoro-3-methoxyphenylboronic acid to form a methyl isobutyl ketone solution comprising the 4-chloro-2-fluoro-3-methoxyphenylboronic acid and an aqueous phase; separating the methyl isobutyl ketone solution comprising the 4-chloro-2-fluoro-3-methoxyphenylboronic acid from the aqueous phase; reacting the 4-chloro-2-fluoro-3-methoxyphenylboronic acid in the methyl isobutyl ketone solution with methyl 4-(acetylamino)-3,6-dichloropyridine-2-carboxylate, without concentrating or isolating the 4-chloro-2-fluoro-3-methoxyphenylboronic acid from the methyl isobutyl ketone solution, to produce methyl 4-(acetylamino)-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate; and deacetylating the methyl 4-(acetylamino)-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate to produce methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate.