A novel dicationic ionic liquid as a highly effectual and dual-functional catalyst for the synthesis of 3-methyl-4-arylmethylene-isoxazole-5(4H)-ones

A novel dicationic ionic liquid, N , N , N ′, N ′-tetramethyl- N , N ′-bis(sulfo)ethane-1,2-diaminium mesylate [TMBSED][OMs] 2 ), has been produced, and identified by analysis of its 1 H NMR, 13 C NMR, FT-IR, mass and thermal gravimetric data. Thereafter, it has been utilized as a highly effectual, homogeneous and dual-functional catalyst to promote the multi-component reaction of ethyl acetoacetate, hydroxylamine hydrochloride and arylaldehydes under solvent-free conditions for the synthesis of 3-methyl-4-arylmethylene-isoxazole-5(4 H )-ones. Due to the dual-functionality of [TMBSED][OMs] 2 (possessing acidic and basic sites), and also having two sites of each, it was a highly effective and general catalyst for the synthesis. Moreover, a plausible and attractive mechanism based on the dual-functionality of the catalyst has been proposed. Graphical Abstract