Process for the preparation of herbicidal carboxylic acid salts

摘要

A process for preparing a herbicidally active carboxylic acid salt comprises the steps of: i) combining a carboxylic acid with a high-boiling, water-immiscible organic solvent to obtain a solution or slurry; ii) treating the solution or slurry produced in step (i) with a base to form a carboxylic acid salt; iii) removing solvent from the mixture produced in step (ii) to obtain a carboxylic acid salt cake; and v) drying the cake obtained in step (iii). The process is particularly suitable for preparing a salt of dicamba (3,6-dichloro-2-methoxybenzoic acid). Dicamba was dissolved in toluene; sodium hydroxide in water was added; the solvents were evaporated; dicamba-sodium was obtained after centrifugation and drying.