The present invention relates to a method for the production of substituted 2-aryl malonic acid esters of the general formula (I), wherein R stands for C1-C6-alkyl or C1-C4-alkoxy-C1-C4-alkyl; Ar stands for phenyl or a heteroaromatic 5-member or 6-member ring; wherein each C atom contained in the above-named groups potentially carries a substituent RA; RA stands for F, C1, CN, NO2, C1-C4-alkyl, C1-C4-haloalkyl, C1-C4-alkoxy, C1-C4-haloalkoxy, etc., or two adjacent substituents RA form a ring together with the carbon atoms to which they are bound; and wherein a malonic acid ester is converted with a base and an aryl bromide in the presence of a copper salt, characterized in that 0.1 to 0.65 mole equivalents of the base are substituted for 1 mole equivalent of the malonic acid ester.