MW-promoted synthesis of coumarines using IL-ONO as recyclable base catalyst under solvent-free conditions

A mild, efficient and solvent-free MW-promoted Knoevenagel reaction for the synthesis ofcumarines in nitrite ionic liquid (IL-ONO) is described. This ionic liquid plays as weakLewis base catalyst, which can be easily recovered and reused in several runs. Thesatisfactory results were obtained with good yields, short reaction time and simplicity inthe experimental procedure.