Evaluation of the catalytic activity of cobalt (II) immobilized on magnetic hydrothalcite (Fe3O4 @ HT @ AEPH2-CoII) in the preparation of xanthene derivatives

In this study, we present a versatile and easy procedure for modifying a ferrite nanoparticle so step by step. A new nanocatalyst was prepared via CoII immobilized onto an aminated ferrite nanoparticles (Fe3O4@HT@AEPH2-CoII). The nanocatalyst was fully characterized by FT-IR, EDX, FE-SEM, TGA, XRD,, EDS and VSM analyses. In the preparation of 14 aryl-14H-dibenzo[a.j] xanthenes, the corresponding nanocatalyst shown great catalytic activity. The reaction contains expeditious reusable catalyst (Fe3O4@AEPH2-CoII) that promotes condensation between aromatic aldehydes and β-naphthol. Also, the environmentally toxic solvents were eliminated. A significant improvement in the synthetic efficacy (95%, yield) was obtained by this new sustainable and eco-friendly protocol as well as high purity. The current procedure as a green protocol offers benefits including a simple operational procedure, an excellent yield of products, mild reaction conditions, minimum chemical wastes, short reaction time, and easy catalyst synthesis. Without any significant reduction in the catalytic performance, up to five recyclability cycles of the catalyst were obtained. The optimization results suggest that the best condition in the preparation of xanthene derivatives is 0.003 gr of the Fe3O4@HT@AEPH2- CoII nano catalyst under solvent free at 90 ◦C. The proposed protocol could be applied on a wider scope of the substrate (i.e., electron-deficient and electron-rich).