Effective fabrication of poly(anilin-formaldehyde)-supported hybrid nanomaterial and catalytic synthesis of dihydropyridines

In this study, Fe3O4@SiO2-PAF-SO3H nanocomposite was successfully fabricated by immobilization of sulfonic acid groups on the surface of poly(anilinformaldehyde)supported on magnetic Fe3O4@SiO2 nanoparticles through layerbylayer assembly. Fe3O4@SiO2-PAF-SO3H composite nanostructure has been fully characterized using various techniques including the Fouriertransform infrared spectroscopy (FTIR), X-ray powder diffraction patterns (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive Xray spectroscopy (EDS) and vibrating sample magnetometry (VSM). The onepot synthesis of mono and bis 1,4-dihydropyridine derivatives, as pharmaceutically interesting compounds, have been achieved in high yields via threecomponent and pseudo five component condensation of an aromatic aldehyde, ammonium acetate and ethyl acetoacetate in the presence of Fe3O4@SiO2-PAF-SO3H as a novel retrievable hybrid nanocatalyst under solventfree conditions. This protocol has advantages in terms of short reaction time, solventfree condition, high yield and purity, easy workup and ecofriendly process as well as recyclability of the nanocatalyst (at least 6 times) with no decrease in catalytic activity.