Process for preparing purified alkali metal salts of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate without isolation of intermediates

摘要

This invention relates to a 5 step process for preparing a purified alkali metal salt of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate in one reaction vessel without isolation of intermediates. The steps are as follows: A) reacting an alkali metal salt of 4-hydroxybenzenesulfonic acid with a C2 to C4 carboxylic anhydride in a solvent to form an alkali metal salt of 4-acyloxybenzenesulfonic acid and a C2 to C4 carboxylic acid. B) adding an [(1-oxyalkanoyl)amino]alkanoic acid and a transesterification catalyst to the reaction product of step A) and heating at a temperature and pressure sufficient to maintain reflux of the solvent and to remove the C2 to C4 carboxylic acid from the reaction vessel to form a reaction mixture containing an alkali metal salt of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate. C) removing the solvent from the reaction mixture formed in step B). D) mixing the alkali metal salt of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate product of step C) with acetic acid. E) and finally separating the product from the acetic acid. The purified alkali metal salt of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate product is useful as a bleach activator in detergents.