One-pot Synthesis of Novel Thiophene Containing Aminonaphthols using Fe3O4 Nanoparticles as a Recyclable Heterogeneous Catalyst

Metal oxide and metal oxide nanoparticles are gaining significant importance due to their reusability and wide range of catalytic applications in many organic transformations. To report simple and efficient Fe3O4 catalyzed one-pot five-component reaction protocol to synthesize novel thiophene containing aminonaphthols under solvent-free conditions. To prepare the Fe3O4 nanoparticles by facile and simple co-precipitation method and surface characterization was done using FT-IR, XRD, BET, SEM, and TEM analysis technique. Aminonaphthol derivatives bearing thiophene moiety were synthesized using Fe3O4 nanoparticles under solvent-free conditions. The prepared nanoparticles are smaller in size (15nm) and can be easily detachable. It can be recycled and reused five times without any significant loss of catalytic activity with excellent yields in a short time. The existing protocol for synthesizing amino naphthol becomes feasible and attractive due to the reusability of the catalyst, excellent catalytic performance, and eco-friendly procedure. In conclusion, Fe3O4 nanoparticles provide a simple, efficient, and greener one-pot five-component synthetic approach to synthesize thiophene containing aminonaphthols. Excellent catalytic activity was perceived in a short reaction time without any co-catalyst or any other activator. Moreover, reusability of catalyst, high yields, and environmentally benign solvent-free condition are vital factors of this protocol.