Influence of Oxidation Conditions on the Yield of 2-Substituted Imidazole-4,5-dicarboxylic Acids

Conditions were found which allow 2-alkyl-substituted imidazole-4,5-dicarboxylic acids to be synthesized in preparative quantities by the oxidation of 2-alkylbenzimidazoles with hydrogen peroxide. It was shown that optimal results can be obtained at the concentration of 2-alkylimidazole in sulfuric acid of 1 M and the hydrogen peroxide: 2-alkylbenzimidazole molar ratio of 11: 1. Oxidation under these conditions results in higher yields of the target 2-alkylimidazole-4,5-dicarboxylic acids, including those with a branched alkyl group.