Novelties of low energy microwave irradiation in tri-phase vis-à-vis bi-liquid phase-transfer catalysis in selective etherification of aromatic phenols

Rate enhancement by order of magnitude and 100% selectivity are realized in the synthesis of aromatic ethers when bi-liquid phase-transfer catalyzed reactions are converted into solid–liquid reaction with omega water phase. Further enhancement is obtained when tri-liquid phases are created. Under the influence of low energy microwave irradiation, there is still more enhancement in the rates of reaction with total selectivity to the ether in comparison with the conventional heating at the same temperature. The current work demonstrates that a low input of 50 W leads to remarkable enhancement in rates without any destruction of the catalyst in comparison with conventional heating for all types of PTC.