Highly effectual synthesis of 4H-pyrano [2, 3-c] pyrazoles using N1, N1, N2, N2-tetramethyl-N1, N2-bis (sulfo) ethane-1, 2-diaminium trifluoroacetate as a dual-functional catalyst

In this research study, highly effective preparation of 4H-pyrano[2, 3-c]pyrazoles was discussed. The one-pot multi-component reaction between the malononitrile, arylaldehydes and 3-methyl-1-phenyl-1H-pyrazol-5 (4H)-one using protic acidic ionic liquid N1, N1, N2, N2-tetramethyl-N1, N2-bis (sulfo) ethane-1, 2-diaminium trifluoroacetate ([TMBSED][TFA]2) under the mild and solvent-free conditions have furnished the title compounds with high yields in short times. Additionally, an attractive mechanism considering dual-functionality of the catalyst was proposed ([TMBSED][TFA]2 with acidic and basic sites).