METHODS OF PRODUCING METHYL 4-AMINO-3-CHLORO-6-(4-CHLORO-2-FLUORO-3-METHOXYPHENYL)PYRIDINE-2-CARBOXYLATE

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. 1. A method of producing methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxy-phenyl)pyridine-2-carboxylate , comprising:adding methyl isobutyl ketone to an aqueous solution comprising 4-chloro-2-fluoro-3-methoxy-phenylboronic acid to form an organic phase comprising the 4-chloro-2-fluoro-3-methoxy-phenylboronic acid and an aqueous phase;separating the organic phase comprising the 4-chloro-2-fluoro-3-methoxyphenylboronic acid from the aqueous phase;reacting the 4-chloro-2-fluoro-3-methoxyphenylboronic acid 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; anddeacetylating 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.2. The method of claim 1 , wherein adding methyl isobutyl ketone to an aqueous solution comprising 4-chloro-2-fluoro-3-methoxyphenylboronic acid comprises forming the organic phase comprising methyl isobutyl ketone and the 4-chloro-2-fluoro-3-methoxyphenylboronic acid and the aqueous phase comprising water and ...

PROCESSES FOR THE ISOLATION OF 4-AMINO-3-CHLORO-6-(4-CHLORO-2-FLUORO-3-METHOXYPHENYL)PYRIDINE-2-CARBOXYLIC ACID

Processes for the preparation and isolation of -amino--chloro--(-chloro--fluoro--methoxyphenyl)pyridine--carboxylic acid. 1. A process for the isolation of 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acid which comprises:(a) neutralizing an aqueous solution of an alkali metal or alkaline earth metal salt of 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acid with an excess of 85-99 percent formic acid at a temperature from about 45 to about 90° C. to produce an aqueous mixture of 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acid;(b) cooling the aqueous mixture of 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acid to about 10 to about 25° C. to crystallize the 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acid, and(c) collecting the crystalline 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)-pyridine-2-carboxylic acid. This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/736,820 filed Dec. 13, 2012, the disclosure of which is expressly incorporated herein by reference.Provided herein are improved processes for the preparation and isolation of 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acid.U.S. Pat. No. 7,314,849 (B2) describes inter alia the preparation 4-amino-3-chloro-6-(poly-substitutedphenyl)pyridine-2-carboxylic acids and their use as herbicides, including 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acid. The parent acids are conveniently prepared by the hydrolysis of either the corresponding esters or the corresponding protected N-acetylated esters. However, when the sodium salt of 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acid resulting from hydrolysis is neutralized with an inorganic acid such as hydrochloric acid, a very fine precipitate is formed which is difficult to ...

Methods of producing methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate

Methods of producing methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate

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.

Methods of producing methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate

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.

Quaternary pyridinium salt inhibitor system for gas conditioning solutions

A B S T R A C T The present invention resides in the area of corrosion inhibition in gas conditioning where CO2 and small amounts of H2S are removed by an absorbent. The invention is an inhibitor composition for alkanolamine solutions and other absorbents for removing CO2 and small amounts of H2S from gas streams, comprising an inhibiting concentration in the absorbent of a combination of one part by weight of a quarternary pyridinium salt and either (1) 0.001-10 parts of a thio compound which is a water-soluble thiocyanate, a water-soluble sulfide, or an organic thioamide, or (2) 0.01-10 parts of a lower alkylene-polyamine, a corresponding polyalkylenepolyamine or mixture thereof, wherein the alkylene units contain 2-3 carbon atoms. The advantages obtained over the prior art are less corrosion than results from numerous known inhibitor combinations, and the claimed inhibitor systems are essentially non-toxic, in contrast with previous inhibitor systems using arsenic, antimony or vanadium.

Cobalt-containing inhibitor for sour gas conditioning solutions

A B S T R A C T The present invention resides in the area of corrosion inhibition in gas conditioning solutions. The invention is a composition for inhibiting corrosion of iron and steel by carbon dioxide in gas conditioning solutions, consisting of inhibiting concentra-tion of one part by weight of a quaternary pyridinium salt and 0.001-10 parts of a thio compound which is a water--soluble thiocyanate or an organic thioamide, and a small amount of cobalt as a water-soluble divalent cobalt compound. The advantages obtained are that corrosion is decreased substantially compared with previous inhibitor systems, when substantial amounts of carbon dioxide are removed by the solution, and that the present inhibitor system is non-toxic in contrast to previous systems employing arsenic, antimony or vanadium.

Methods of producing methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate

The disclosure relates to a method of producing methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxy-phenyl)pyridine-2-carboxy late, comprising: adding methyl isobutyl ketone to an aqueous solution comprising 4-chloro-2-fluoro-3-methoxy-phenylboronic acid to form an organic phase comprising the 4-chloro-2-fluoro-3-methoxy-phenylboronic acid and an aqueous phase; separating the organic phase comprising the 4-chloro-2-fluoro-3-methoxyphenylboronic acid from the aqueous phase; reacting the 4-chloro-2-fluoro-3-methoxyphenylboronic acid with methyl 4-(acetylamino)-3,6-dichloropyridine-2-carboxylate in methyl isobutyl ketone in the presence of a palladium catalyst and a ligand 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 methy14-amino-3-chloro-6-(4-chloro-2-fluoro-3 -methoxypheny l)pyridine-2-carboxylate.

Methods of producing methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate

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.