Identification of oxidation products and oxidation pathways of high molecular weight dicarboxylic acids under hydrothermal condition

In order to investigate the oxidative reaction pathways of dicarboxylic acids under hydrothermal condition, sebacic and azelaic acids of high molecular weight dicarboxylic acids were oxidized at 400 °C, and intermediate products were identified in detail by GC/MS, HPLC, and 1H NMR analyses. The oxidation of high molecular weight dicarboxylic acids proceeded with the consecutive oxidation of higher to lower molecular weight dicarboxylic acids through α-, β-, and γ-oxidations, as do monocarboxylic acids. The oxidation of dicarboxylic acids was also accompanied by oxidative decarboxylation, which led to the formation of monocarboxylic acids.