Synthesis and characterization of Ni-MOF and CoFe2O4/Ni-MOF as reusable heterogeneous catalysts for the synthesis of 5-substituted 1H-tetrazole.

The purpose of this study is to describe the synthesis of typical porous metal-organic framework (MOF) materials based on nickel 2,6-pyridinedicarboxylic acid (Ni-MOF). Also, using a simple in-situ solvothermal method, CoFe2O4/nickel 2,6-Pyridinedicarboxylic acid (CoFe2O4/Ni-MOF) was synthesized as a magnetic MOF composite. The CoFe2O4/Ni-MOF and Ni-MOF were characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectrometer (EDS), vibrating-sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption - desorption isotherm to confirm successful integration and its porous, and magnetic nature. The potential of Ni-MOF and CoFe2O4/Ni-MOF as catalysts was investigated for the one-pot synthesis of a diverse array of pharmaceutically active 5-substituted 1H-tetrazole derivatives. To optimize the reaction conditions, the efficiency of catalyst amounts, various solvents, and different temperatures has been studied using benzonitrile (1 mmol), a catalyst, and NaN3 (1.2 mmol) as a model reaction. The developed material demonstrated remarkable efficiency (80%) in the synthesis of 5-(phenyl)-1H-tetrazole. An important aspect of this strategy is that it adheres to ecologically favorable reaction conditions (The reactions are based on green chemistry under mild reaction conditions in H2O/EtOH solvent, at a relatively low temperature compared to the reported work). The CoFe2O4/Ni-MOF composite significantly outperformed the pure Ni-MOF, achieving an 80% yield in 20 min versus 40 min for the Ni-MOF, using the same catalyst mass (80 mg) in H2O /EtOH (1:1) solvent. The research demonstrates the deliberate design of a high-performance, retrievable magnetic MOF catalyst for sustainable organic synthesis.