Srm Chemical, Ltd. Co.

Ptrl East, Inc.

R. T. Alamo Venture I LLC

Steven G Mobley

Stefan Kwiatkowski

Lowell J Lawrence

Paul D Smith

Stephan Kwiatkowski

Maya Siddidqui

Kryzsztof Pupek

Sudarsan Mukhopadhyay

Rodney Eisenberg

Miroslaw Golinski

A high-yield, 4-step synthesis for flosequinan

Method of synthesizing flosequinan from 4-fluoroanthranilic acid

Dikegulac, its salts and related derivatives are prepared by reacting 2-Keto-L-gulonic acid with 2,2 dimethoxypropane at an elevated temperature in the presence of a catalytic amount of a strong acid. This produces a reaction intermediate which is then reacted with a base to complete hydrolysis and produce an acid salt of dikegulac. Simple concentration and phase separation techniques are used to provide a more efficient, environmentally friendly and cost effective process.

Process for producing dikegulac, its salts and derivatives

The invention is a process to manufacture the intermediate secondary amine N-ethyl-2-chloro-6-fluoro-benzylamine, and then the process of reacting this intermediate to manufacture the herbicide flumetralin. Equimolar quantities of monoethylamine, sodium hydroxide, and 2-chloro-6-fluorobenzyl chloride are reacted at a temperature between about 70.degree. C. and about 100.degree. C. in a composition containing at least 2.5 times the required quantity of monoethylamine. The reagent monoethylamine functions as solvent and heat sink for the reaction, and also minimizes the formation of undesired byproducts. The excess monoethylamine is removed after formation of the intermediate. Then, equimolar quantities of sodium hydroxide in water and molten 4-chloro-3-5-dinitrobenzotrifluoride are added to the intermediate, and the temperature is controlled between about 90.degree. C. and about 115.degree. C. The product of this reaction is relatively pure, i.e., 98 percent by weight, molten flumetralin. It is advantageous to wash the product with boiling water to facilitate removal of salt and excess sodium hydroxide.

Method of manufacturing flumetralin

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Lexington, KY, United States of America

Steven G Mobley