Selective engineering using Mg–Al calcined hydrotalcite and microwave irradiation in mono-transesterification of diethyl malonate with cyclohexanol

• Synergism between microwave irradiation and solid base catalysis.
• Mono-transesterification of diethyl malonate with cyclohexanol Mg–Al calcined hydrotalcite.
• Microwave irradiation showed more than threefold increase vis-a-vis conventional heating.
• 69% conversion with 98% selectivity for cyclohexyl ethyl malonate at 100 °C in 2 h.
• Full catalyst characterization and theoretical analysis to develop kinetic model.

Selectivity engineering aspects of synergism between microwave irradiation and solid base catalysis is investigated for a highly selective mono-transesterification of diethyl malonate with cyclohexanol using Mg–Al calcined hydrotalcite as catalyst. Microwave irradiation showed threefold increase in cyclohexanol conversion vis-a-vis conventional heating and only the mono-transesterified product was obtained. The catalyst was characterised by XRD, FT-IR, CO2-TPD, surface area and pore size analysis. Hydrotalcite with Mg:Al composition as 3:1 gave the best results. Effect of various parameters was studied on conversion and selectivity. Under optimised reaction conditions, 69% conversion with 98% selectivity for cyclohexyl ethyl malonate was obtained for catalyst loading of at 100 °C in 2 h. The catalyst showed excellent reusability. Complete theoretical and experimental analysis has been done to develop a kinetic model for the reaction.

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