ECO-FRIENDLY APPROACHES IN HETEROCYCLIC CHEMISTRY FOR MODERN MEDICINAL APPLICATIONS

Heterocyclic compounds constitute one of the most important classes of organic molecules due to their extensive occurrence in natural products, pharmaceuticals, agrochemicals, and advanced materials. More than 75% of clinically used drugs contain heterocyclic moieties, demonstrating their immense significance in medicinal chemistry. However, conventional synthetic methods for heterocyclic compounds often involve hazardous solvents, toxic reagents, high energy consumption, and environmentally harmful by-products. Green chemistry has emerged as an efficient and sustainable approach for overcoming these limitations. Eco-friendly synthetic methodologies such as microwave-assisted synthesis, ultrasound-assisted synthesis, solvent-free reactions, multicomponent reactions, ionic liquids, deep eutectic solvents, nanocatalysis, and biocatalysis have revolutionized heterocyclic chemistry. These sustainable approaches minimize waste generation, improve atom economy, reduce reaction times, and enhance product yields. The present chapter discusses the importance of heterocyclic compounds, various eco-friendly synthetic approaches, and their modern medicinal applications including antimicrobial, anticancer, antiviral, anti-inflammatory, antidiabetic, and antioxidant activities. Furthermore, the chapter highlights recent advancements, challenges, and future perspectives in sustainable heterocyclic chemistry.