Synthesis of some 4H-Pyran Derivatives Using Bio-synthesized ZnO Nanoparticles and the Evaluation of their Biological Activities

ZnO Nanoparticles were simply synthesized by green biosynthesis method using ficus carica leaf extract. The structure of these nanoparticles was assigned using Fourier transform infrared spectroscopy (IR), Field emission-scanning electron microscopy (FE-SEM) and X‐ray powder diffraction (XRD). The catalytic activity of these nanoparticles was studied for synthesis of 4H-pyrans. A series of 4H-pyrans 3(a-l) were synthesized in good to high yields by reaction of corresponding α,α′-bis(substituted benzylidene) cycloalkanones and malononitrile in the presence of ZnO nanoparticles as a catalyst at 110 ℃. This environmentally friendly method has some advantages such as high efficiency, use of available catalyst, solvent-free reaction conditions and easy operation. The antibacterial activity of synthesized 4H-pyrans was also tested using Staphylococcus aureus and Escherichia coli bacterial strain.