Triazolopyridazines as Privileged Heterocyclic Scaffolds: Advances in Synthesis, Structure- Activity Relationship and Therapeutic Applications

The pursuit of effective cancer treatment with high specificity and minimal side effects remains crucial for improving human health. Compounds containing triazolopyridazine scaffolds have garnered significant interest among researchers due to their distinctive chemical architecture and diverse biological properties. This review comprehensively examines synthetic pathways for both [1,2,3]triazolopyridazine and [1,2,4]triazolopyridazine isomers, with particular emphasis on the [1,2,4]triazolo[4,3-b]pyridazine nucleus, reflecting their greater representation in scientific literature. Additionally, we provide a thorough examination of optimization strategies, structure-activity relationship (SAR) and therapeutic efficacy for [1,2,4]triazolo[4,3-b]pyridazine derivatives, established as a privileged motif in numerous anticancer agents. By analyzing recent advances in synthetic methodologies and biological evaluations, with specific focus on anticancer applications, we offer valuable insights to guide medicinal chemists in the rational design of novel triazolopyridazine-based compounds with enhanced anticancer potency and optimized pharmacological profiles.