Synthesis and characterisation of mixed oxides of Co–Ni catalyst and its application in microwave mediated synthesis of Benzo[b]Pyrans

Abstract

We present an easy and sustainable procedure for the productive preparation of tetrahydrobenzo[b]pyran derivatives by means of many compounds condensation of dimedon, malononitrile and several aromatic aldehydes utilizing mixed bimetallic oxides of Co–Ni as a catalyst under microwave irradiation. Present protocol involves green synthesis of mixed Co–Ni oxide catalyst using milky latex of Euphorbia neriifolia. The prepared mixed Co and Ni oxide was analyzed by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Fourier Transform Infra-Red Spectroscopy (FT-IR), Energy Dispersive X-ray Analysis (EDAX), X-ray Photoelectron Spectroscopy (XPS) & Brunauer-Emmett- Teller Analysis (BET). This green approach's significance is demonstrated by its one-pot synthesis, convenient without use of solvent shows good isolated yields. Multiple analytical techniques such as Fourier transform infrared spectroscopy (FT-IR), 1H and 13C nuclear magnetic resonance (NMR) spectroscopy are utilized to derive the structural properties. The mixed metal oxides of Co and Ni was found to be catalytically active and can be reused 12 times without significant loss of catalytic activity.