Insight into the Various Approaches Undertaken for the Synthesis of Quinoline Hybrids Imparting Diverse Therapeutic Activities

: Quinoline is one of the promising and prominent biologically active N-based heterocyclic compounds. This review paper aims to discuss the synthetic approaches, summarized from various research articles on the preparation of quinoline derivatives intended for different therapeutic activities like antifungal activity, anticancer activity, anticonvulsant activity, antitubercular activity, antimalarial activity, anti-Alzheimer activity and so on. The comprehensive study complies with all related publications and trademark publications demonstrating the synthesis and biological aspects of quinoline derivatives. Various types of quinoline hybrids were synthesized and treated for therapeutic activity, including anticancer, antitubercular, anti-Alzheimer, antioxidant, and antifungal activity, which have been analyzed. Quinoline is a planner hetero-aromatic compound with the chemical formula C9H7N. Several wellknown synthetic routes to the quinoline skeleton include Friedlander synthesis, Knorr quinoline synthesis, and Skraup reaction. Researchers may use other techniques or alter current strategies to reach their objectives, depending on what exact structure and therapeutic action they are investigating. The availability of starting materials, reaction conditions, scalability, desired regioselectivity, and functionalization of the quinoline core all have a role in the choice of synthetic method. This review covers the latest literature and knowledge on the synthetic procedures for numerous quinoline and its derivatives and their biological and pharmacological application.