Introduction of a new piperazine-based ionic liquid as an efficient catalyst for the biginelli reaction

Catalytic systems in organic synthesis are constantly developing and expanding. Meanwhile, ionic liquids are very much considered for some reason, including reasonable prices, environmental compatibility, high reactivity, recyclability and selectivity [1]. So far, ionic liquids have been used successfully as a catalyst in many of the major synthetic reactions such as aldol condensation, protection of carbonyls, Koch carbonylation, Diels-Alder reactions, Mannich reaction, Heck reaction, Knoevenagel reaction and heterocyclic synthesis [2]. 3,4-Dihydropyrimidin-2(1H)-ones (DHPMs) and their derivatives, due to their significant biological properties, are important compounds in the pharmaceutical field. These compounds are used as medicines for antihypertensive, antibacterial, antiviral, anti-cancer and anti-HIV drugs in medicine [3].In this work, a piperazine-based ionic liquid is synthesized and after characterization with FT-IR, Mass and NMR spectroscopy, is used as a catalyst for the Biginelli reaction. The main advantages of using this ionic liquid is high efficiency, acceptable reaction times, excellent yields of the achieved products and reusability of the catalyst.