Design and synthesis of some new biologically active amidoalkyl naphthols in the presence of sulfonic acid functionalized silica-coated Fe3O4 nanoparticles

The novel functionalized silica-coated Fe3O4 nanoparticles, Fe3O4@SiO2-TETA-SO3H, were synthesized by stabilizing of sulfonic group on the surface of silica-coated Fe3O4 nanoparticles. The structure of these nanoparticles was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, thermal gravimetric analysis and vibrating sample magnetometer and energy dispersive X-ray spectroscopy. The activity of the Fe3O4@SiO2-TETA-SO3H nanoparticles as a catalyst was investigated for benign one-pot synthesis of some new amidoalkyl naphthols using fatty acids as bio-based resources. This reaction afforded the desired products within short reaction times, high yields and easy work-up procedure. This acidic catalyst could be recycled and reused for six runs without significant change in its activity. Furthermore, the biological activity of the synthesized fatty amidoalkyl naphthols was evaluated against Staphylococcus aureus (ATCC 25,923) and Escherichia coli (ATCC 25,922) bacteria.