BigPatents India

Disclosed is a method for producing a dicarboxylic acid of formula (I) H-OOC-(n-C4Hx)-COO-H, in which x represents 6 or 8, from acrylic acid. Said method is characterized by the fact that a) a dicarboxylic acid diester of formula (II) R1-OOC-(n-C4Hx)-COO-R2, in which x represents 6 or 8 and R1, R2 independently represent C1-, C2-, C3-, C4-alkyl, aryl, heteroaryl and can be identical or different, is reacted with acrylic acid so as to obtain a dicarboxylic acid of formula (I) and a mixture of acrylic acid ester of formula C2H3-COOR1 and C2H3-COOR2, in which R1 and R2 have the meanings mentioned above; b) the dicarboxylic acid of formula (I) obtained in step (a) is separated from the reaction mixture obtained in step (a); c) the C2H3-COOR1, C2H3-COOR2, or the mixtures thereof obtained in step (a) are dimerized so as to obtain n-butene dicarboxylic acid diester; and d) the dicarboxylic acid diester obtained in step (c) is split into the corresponding dicarboxylic acid of formula (I).