Catalytic application of 1-(carboxymethyl)pyridinium iodide on the synthesis of pyranopyrazole derivatives

•Study of 1-(carboxymethyl) pyridinium iodide {[cmpy]I} as acetic acid functionalized pyridinium salt and catalyst.•Catalytic application of 1-(carboxymethyl) pyridinium iodide on the synthesis of pyranopyrazoles.•This method has the high yield, the shorter reaction times, and compliance with the green chemistry protocols.•Easy recovery and reusability of nanostructure molten salt catalyst.

In this investigation, acetic acid functionalized pyridinium salt, namely 1-(carboxymethyl)pyridinium iodide {[cmpy]I}, has been introduced as reusable catalyst for green, simple and efficient synthesis of 6-amino-4-(4-methoxyphenyl)-5-cyano-3-methyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles by the one-pot tandem four-component condensation reaction of aryl aldehydes with ethyl acetoacetate, malononitrile and hydrazine hydrate at 100 °C under solvent-free conditions. Additionally, 1H and 13C NMR, mass, CHN analysis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), X-ray diffraction analysis (XRD), and calculation of crystallite size and inter planer distance of the catalyst have been investigated.

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