Esterification of dicarboxylic acids to diesters over Mⁿ⁺-montmorillonite clay catalysts

Esterification of dicarboxylic acids with various alcohols and phenols in presence of metal exchanged montmorillonite clay catalyst (Mⁿ⁺-mont; Mⁿ⁺ = Al³⁺, Fe³⁺, Cr³⁺, Zn²⁺, Mn²⁺, and Ni²⁺) is studied. Among the catalysts used, Al³⁺-mont was found to be the most effective, as it gave good to excellent yields of esters under mild reaction conditions. The heterogeneous catalyst presented here can be regenerated and reused. All these features indicate the high potential of the reaction as “green chemistry” process.