Zinc Fumarate MOF: An Efficient and Facile Catalyst for Biginelli Reaction

Abstract

Dihydropyrimidinones (DHPMs) and its thione derivatives are the well-known heterocyclic compounds recognized for their vast biological potential. In this work, we report the synthesis and characterization of zinc fumarate (Zn-fum) MOF and its use as a novel catalyst in the Biginelli reaction. The metal–organic framework (MOF) was synthesized using a solvothermal method and characterized by analytical methods including XRD, FTIR, FESEM, HRTEM, and EDX. As per XRD, SEM, and TEM analysis, the synthesized Zn-fum MOF has elongated hexagonal crystalline structure with significant porosity. The MOF possesses a high specific surface area and total pore volume of 1298 m²g⁻¹ and 0.10221 cm³g⁻¹ with 11.82 nm pore diameter as per BET analysis. The catalytic presence of the Zn-fum MOF in the Biginelli reaction delivered a range of dihydropyrimidinones in high to excellent yield (89%–98%) in a short span of 20 min at 80°C under solvent-less conditions. Being heterogeneous, the Zn-fum MOF was easily recoverable and reusable for multiple catalytic cycles without significant loss of activity. The synthesized DHPM derivatives were also evaluated for their antibacterial and antioxidant abilities. Among the 10 compounds tested, several demonstrated significant inhibition of both Gram-positive and Gram-negative bacteria, as indicated by the disc diffusion method. The antioxidant activity, as assessed by DPPH and reducing power assays, showed %RSA (radical scavenging activity) values ranging from 60.7% to 65.7%, compared to 80.9% for the standard ascorbic acid. These findings highlight the promising catalytic, antibacterial, and antioxidant properties of the synthesized compounds.