Efficient aldol condensation by using modified CaO as solid-base catalysts

Abstract

A new type of solid-base catalyst for aldol condensation reaction was prepared by modifying commercial CaO with benzyl bromide in a simple way. It was found that modified CaO can effectively catalyze the aldol condensation of acetophenone and benzaldehyde to produce chalcone with a high conversion and good selectivity. The catalyst gave a higher yield (90.5%) of chalcone than commercial CaO. The high catalytic activity and stability of this catalyst was related to the organic modifier with a hydrophilic functional group that improved the diffusion of grease to the catalyst surface and prevented its hydration. The influence of several reaction parameters, such as temperature, catalyst loading and the moisture absorption rate of modified CaO, was investigated. From the results, the basic centers of modified CaO are stable and hardly poisoned by CO2 unlike commercial CaO. The catalyst was completely recyclable without significant loss in activity up to five reaction cycles. Moreover, this catalyst showed a promising future in providing an environmentally clean process for the industrial sector.