One pot oxidative esterification of benzaldehyde over a supported Cs-salt of mono nickel substituted phosphotungstate

Abstract

As a cleaner alternative to traditional two steps procedures, the one pot oxidative esterification of benzaldehyde to methyl ester was carried out over a supported Cs salt of mono nickel substituted phosphotungstate (CsPW₁₁Ni). CsPW₁₁Ni was supported on ZrO₂ and characterized using various physico-chemical techniques. The influence of reaction parameters, such as molar ratio of substrate to H₂O₂, amount of catalyst, reaction time, and reaction temperature, on the oxidative esterification reaction was investigated. Moreover, the catalyst could be recovered and reused up to three cycles without significant loss in selectivity. The present heterogeneous catalytic system was found to be efficient not only in terms of activity (63%) but also in selectivity (79%) of the desired product.