PROCESS FOR THE PREPARATION OF A DICARBOXYLIC ACID

摘要

A process for the preparation of a dicarboxylic acid, comprising the steps of (a) contacting a conjugated diene with carbon monoxide and water in the presence of a catalyst system including a source of palladium, a source of an anion and a bidentate phosphine ligand, to obtain a mixture comprising an ethylenically unsaturated acid product; (b) reacting the mixture obtained in step (a) further with carbon monoxide and water to obtain the dicarboxylic acid in admixture with the ethylenically unsaturated acid; (c) separating the dicarboxylic acid from a liquid filtrate comprising the catalyst system; and (d) recycling at least part of the obtained liquid filtrate to step (a).