The Esterification of Carboxylic Acid with Alcohol over Hydrous Zirconium Oxide

The esterification of carboxylic acids with alcohols proceeded efficiently with hydrous zirconium oxide to give the corresponding esters in the vapor phase, in the liquid phase, and in an autoclave. The steric hindrance of carboxylic acids and alcohols affected the esterification by lowering the reactivity. With a rise in the reaction temperature, the conversion of the carboxylic acid increased. The dehydration of alcohols was prevented by using hydrous zirconium oxide in spite of the high reaction temperature. The reaction rate is first-order with respect to the concentration of the catalyst and an alcohol and is inversely proportional to that of the carboxylic acid. Transesterification also proceeded efficiently.