A pilot scale process is described for the electrochemical hydrodimerization of dimethyl maleate to tetramethyl butanetetracarboxylate. The reaction is performed in an undivided bipolar cell using graphite electrodes, methanol as the solvent and sodium acetate as the supporting electrolyte. Several hundred kilograms of product were formed. Electrode lifetimes of four hundred hours were achieved with reasonable selectivity (70%) to the desired product Dimethyl succinate is a major (20+%) byproduct along with minor quantities of dimethyl methoxysuccinate.