Cobalt–nickel supported on magnetic mesoporous silica hollow spheres for efficient synthesis of tetrazole derivatives under solvent-free conditions

This study presents the synthesis and characterization of a Co-Ni anchored magnetic mesoporous silica hollow sphere as an efficient and eco-friendly nanocatalyst for the preparation of 1-substituted 1H-1,2,3,4-tetrazole derivatives. The hollow and mesoporous architecture of the catalyst provides a large active surface area, enhancing its catalytic performance. The synergistic interaction between cobalt and nickel on the catalyst surface significantly improves its efficiency. The catalyst was thoroughly characterized using FT-IR, XRD, FE-SEM, TEM, EDS, elemental mapping, BET, ICP-OES and VSM techniques. Its magnetic properties facilitate easy separation and recyclability, with minimal loss of activity over multiple cycles. The nanocatalyst was applied in a solvent-free, three-component reaction involving triethyl orthoformate, sodium azide, and aromatic amines at 80 °C, affording the desired 1-substituted tetrazole derivatives in excellent yields (up to 98%). Reaction parameters, including catalyst loading, temperature, and solvent effects were optimized. Additionally, the obtained tetrazole derivatives were identified by their melting points, FT-IR, ¹H NMR and ¹³C NMR analyses. The key advantages of this catalytic system include its reusability, high efficiency under mild conditions, short reaction times, and production of pure products in high yields.