Method For Producing Acyloxy Benzoic Acids
AssigneeClariant Finance (BVI) Limited
InventorsMelanie Sajitz, Isabel Scheffer, Werner Janitschek
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Abstract
The invention relates to a method for producing acyloxy benzoic acids of the formula (I), in which R1 is a linear or branched saturated alkyl group with 6 to 30 carbon atoms, a linear or branched mono- or polyunsaturated alkenyl group with 6 to 30 carbon atoms, or an aryl group with 6 to 30 carbon atoms. The acyloxy benzoic acids of the formula (I) are produced from para-hydroxy benzoic acid and a corresponding carboxylic acid halogenide in the presence of a base and are advantageously suitable for use as activators for hydrogen peroxide.
Claims9
A process for preparing an acyloxybenzoic acid of the formula (I)
- in which
- R1 is a linear or branched, saturated alkyl group having 6 to 30 carbon atoms, a linear or branched, singly or multiply unsaturated alkenyl group having 6 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms,
- comprising the steps of characterized in that
- a) reacting a carboxylic halide of the formula R1COHal, in which R1 is defined above and Hal is a halide, with para-hydroxybenzoic acid in the presence of base, wherein the base is selected from alkali metal hydroxides, in a solvent mixture comprising water and at least one organic solvent, wherein the organic solvent is isopropanol, at a temperature ≦25° C. and a pH of 9 to 11.5,
- b) adjusting the pH of the reaction mixture after step a), at a temperature ≦25° C., to a pH of 6 to 8 by addition of acid, and
- c) subsequently heating the reaction mixture after step b) to a temperature of 35 to 80° C. and thereafter adjusting the pH of the reaction mixture to a pH of 1 to 4 by addition of acid.
Dependencies are inferred from the claim text.