Synthesis and antibacterial study of 2-amino-4H-pyrans and pyrans annulated heterocycles catalyzed by sulfated polysaccharide-coated BaFe12O19 nanoparticles

In this procedure, the synthesis of ecofriendly, magnetically retrievable BaFe12O19 was reported using a sulfated polysaccharide of algal origin, Irish moss (IM), as bio-matrix and capping agent. The characterization of BaFe12O19@IM was performed by some physicochemical characterization tools, such as Fourier transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, vibrating sample magnetometer, and thermogravimetric analysis. The catalytic performance and recyclability of the introduced heterogeneous catalyst have been explored in the one-pot synthesis of 2-amino-4H-pyrans and pyrans annulated heterocyclic compounds via a three-component reaction between aldehydes, malononitrile, and various C???H activated acidic compound under green reaction conditions. This environmentally benign catalyst displayed high catalytic activity and effective reusability and could maintain its high catalytic efficiency even after six recycling runs. Furthermore, the antibacterial activity of BaFe12O19@IM and the selected compound (4a) toward two types of clinically isolated bacterial strains Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was evaluated. The results revealed that BaFe12O19@IM and 2-amino-4-(4-chlorophenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (4a) showed an effective antibacterial activity against gram-positive S. aureus.