Process of preparing 3-carboxymethyl-2-carboxy-chromones

Abstract

2-Carboxymethyl-3-carboxy-chromones and esters of the formula ##STR1## in which R, R.sup.1 and R.sup.2 each independently is hydrogen, an optionally substituted alkyl, alkenyl, cycloalkyl, cycloalkenyl, aralkyl or aryl group, halogen, hydroxyl, cyano or an optionally substituted alkoxy aryloxy, aralkoxy, alkoxy-carbonyl or dialkylamino group, or R and R.sup.1, together with two carbon atoms of the benzene ring system, form a carbocyclic or heterocyclic 5-membered or 6-membered ring, and R.sup.3 is hydrogen, optionally substituted alkyl, alkenyl, cycloalkyl, cycloalkenyl or aralkyl, are characterized by fungicidal and arthropodicidal activities. The novel compounds are produced by reacting an o-hydroxyacetophenone of the formula ##STR2## with a glyoxylic acid derivative of the formula OCH-COOZ in which Z is a cation, in the presence of a basic compound, followed by acidification to form the dicarboxylic acid and, optionally, the ester.

Dependencies are inferred from the claim text.