METHOD OF SYNTHESIS OF BENZENEPOLYCARBOXYLIC ACIDS Russian patent published in 2002 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to the improved method of synthesis of benzenepolycarboxylic acids, namely, pyromellitic and mellitic acids. Method is performed by electrochemical oxidation of graphite or coal in suspended state and oxidation is carried out in all volume of electrolyte with electrochemically generating "active chloride" as oxidizing agent forming in electrolysis of 10-20% sodium chloride solution, at currant density 0.3-0.5 A/cm² and temperature 50-90 C, from initial pH value of solution 7 using oxide-ruthenium-titanium anode and following isolation of the end product. Proposed ecologically pure method ensures to intensify electrochemical process of synthesis of benzenepolycarboxylic acids by 6-8.5-fold and to simplify process of extraction of the end product from electrolyte. End products are used in industry for production of polyesters, in part, alkyd resins and fibers, chelating agents, drugs, polyimides and pyrrones, electroinsulting covers. EFFECT: improved method of synthesis. 2 cl, 2 tbl, 3 ex