Sustainable synthesis of quinazolinones: exploring multicomponent reactions with a novel magnetic palladium catalyst

This study introduces a sustainable and efficient method for synthesizing quinazolinones, a class of heterocyclic compounds with significant pharmaceutical applications, via a multicomponent reaction (MCR) strategy. The process employs a novel magnetically recoverable palladium catalyst, enabling the coupling of aryl or heteroaryl iodides with a carbonyl source and 2-aminobenzamide in an eco-friendly PEG/water solvent system, facilitated by potassium carbonate as a base. The magnetic Pd catalyst exhibits robust catalytic activity, achieving high product yields (82%-98%) across diverse substrates, including electron-rich and electron-deficient aryl/heteroaryl iodides, underscoring its broad applicability. The catalyst is synthesized and characterized through various techniques, including FT-IR, BET, TGA, EDX, VSM, SEM, TEM, and XRD, which affirm its uniformity and stability. Key advantages of this protocol include exceptional atom economy, elimination of toxic solvents, and mild reaction conditions. The catalyst's magnetic properties allow effortless recovery via external magnetization, retaining >89% activity over five consecutive cycles, enhancing cost-effectiveness and sustainability. The methodology advances sustainable synthetic practices and holds promise for scalable applications in medicinal and industrial chemistry. This work highlights the transformative potential of magnetic nanocatalysts in developing eco-conscious routes to biologically relevant heterocycles.