A Recyclable Heterogeneous Cu/Co/Fe Trimetallic Oxide Nanocatalyst for the Synthesis of 5-Substituted-1H-Tetrazoles

5-Substituted-1H-tetrazoles were synthesized via the [3 + 2] cycloaddition of NaN₃ and several nitriles using Cu_1-xCo_xFe₂O₄ (x = 0, 0.25, 0.5, 0.75, and 1) nanocatalysts in N,N-dimethylformamide (DMF) at 120 °C. The Cu_0.5Co_0.5Fe₂O₄ nanospinel ferrite is the most active nanocatalyst in comparison to other prepared nanocatalysts. This nanocatalyst was easily separated from the reaction mixture using an external magnet and reused for five cycles without any appreciable loss of catalytic activity. The cost-effective and easy availability of the catalyst, simple methodology, high yield, and easy workup are the extra advantages of this method. The structural characteristics of the catalyst were investigated by scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometer analyses.