Multimethod Synthesis of Pyrimidine Using Natural Catalysts

The present study focuses on the development of an environmentally benign and efficient synthetic approach for the preparation of pyrimidine derivatives using natural catalysts derived from biowaste materials. The primary objective of this work was to explore sustainable catalysts such as fruit peel ash, organic acids, and plant extracts and to evaluate their catalytic performance under different reaction methodologies. The synthesis was carried out using ethyl acetoacetate, benzaldehyde, and urea through a multicomponent reaction employing conventional stirring, water bath heating, ultrasonication, and microwave irradiation. The catalytic materials were characterized using infrared spectroscopy, scanning electron microscopy, and X-ray diffraction techniques, which confirmed the presence of functional groups, porous morphology, and catalytically active mineral oxides. Among the various methods investigated, microwave-assisted synthesis under solvent-free conditions demonstrated superior performance, affording high product yield within a significantly reduced reaction time. Ultrasonication also showed considerable improvement compared to conventional methods. The enhanced catalytic activity was attributed to the synergistic effect of acidic and basic sites present in the natural catalysts, which facilitated carbonyl activation, enolate formation, and cyclization. Furthermore, the catalyst exhibited good reusability with only a marginal decrease in efficiency after multiple cycles. Overall, this study highlights a green, cost-effective, and sustainable protocol for pyrimidine synthesis with potential applicability in eco-friendly organic transformations.