Green synthesis of novel pyrano[2,3-c]pyrazole-5-carbonitrile analogues by using Fe5(PW10V2O40)3 nanocatalyst through a one-pot Knoevenagel condensation and Michael addition mechanism

Abstract

A swift and green one-pot method was improved for the preparation of new pyranopyrazole analogues using iron-doped heteropoly acid [(Fe5(PW10V2O40)3] (FePWV) as an efficient catalyst at room temperature and ethanol as the solvent. The one-pot, multi-component reaction combining substituted aldehyde, malononitrile,ethyl acetoacetate, and hydrazine hydrate produces remarkable yields (varying from 88 % to 98 %) for this highly selective technique. Using P-XRD, TGA, BET, FT-IR, TEM, and SEM studies, the synthesized FePWV catalyst was fully characterized. Several spectroscopic methods, including 1H NMR, 15N NMR, 13C NMR, and HRMS, were used to confirm the target molecules' structural information.This environmentally benign method also has other benefits, such as operational simplicity, a stable catalyst with great reusability (up to 7 times), quick reaction times (<20 min), and the absence of chromatographic separations. The proposed method is sustainable and affordable as a result of these properties taken together.