Process for preparation of cyclic carbonate

摘要

A catalytic system comprising of Zinc-substituted polyoxometalate, Na12[WZn3(H2O)2(ZnW9O34)2].48H2O and a Lewis base has been discovered to be efficient chemical fixation of CO2 with epoxides (I) to form cyclic carbonates of structure II as given below: wherein R is selected from a halogen atom, aliphatic and aromatic group. The reaction was carried out at moderate CO2 pressure of 60 psig and in the temperature range 100-140° C. with very high turn number of more than 40,000, with nearly a quantitative conversion and 95-99% selectivity. The Zinc-substituted polyoxometalate catalyst is easy to separate after the reaction by filtration and reusable for many cycles. The reaction can be carried out without any solvent.