Synthesis and characterization of molybdic acid immobilized on modified magnetic nanoparticles as a new and recyclable catalyst for the synthesis of chromeno[4,3-b]chromenes

As the basic task of the current study, molybdic acid immobilized on 3-chloropropyl-grafted magnetic silica-coated Fe3O4 nanoparticles (Fe3O4@SiO2@(CH2)(3)OMoO3H), as a recyclable catalyst, was synthesized and characterized via FT-IR, X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and vibrating sample magnetometer (VSM) analysis. The catalytic performance of this novel nanocatalyst was evaluated for the preparation of a wide range of chromeno[3,4-b]-chromene derivatives in excellent yields. It is a low-cost, nontoxic, and recoverable catalyst that provides environmentally friendly reaction conditions. Additionally, the reaction does not require very high temperatures. The catalyst can be reused many times without a significant loss of its activity.