Synthesis of Di-2-ethylhexyl Maleate Catalysed by Niobic Acid

A new catalyst, niobic acid, was used for the synthesis of di 2 ethylhexyl maleate with yield of 86.4%. The optimum conditions were as follow: molar ratio of maleic anhydride to 2 ethyl hexanol was 1.0∶3.0, reaction time under reflux was 2 hours, mass of catalyst accounted for 8g/mol of maleic anhydride. The catalyst had many advantages, such as easy to be recovered, easible to be used repeatedly and less pollution to the environment.