A Comprehensive Review on Traditional and Modern Synthetic Approaches to Pyrazole and Its Analogs

ABSTRACT

Pyrazoles constitute a pivotal heterocyclic scaffold found in anti‐inflammatory, anticancer, anticonvulsant, antidepressant, and anti‐infective agents, highlighting their significance in pharmaceutical development. This review critically examines two principal synthetic methodologies: (i) the condensation of 1,3‐dicarbonyl compounds and conjugated π‐systems with hydrazine derivatives, focusing on substrate scope, regioselectivity challenges, and mechanistic underpinnings, and (ii) [3 + 2] cycloaddition strategies involving alkynes or activated olefins with 1,3‐dipoles, emphasizing catalyst systems and functional group tolerance. Recent innovations, including solvent‐free microwave‐assisted synthesis, visible‐light photocatalysis, and flow chemistry, are highlighted for their roles in improving atom economy and scalability of pyrazole frameworks. By comparing classical methods with emerging green and continuous synthesis techniques, this review provides practical insights to facilitate the design of efficient and sustainable pyrazole syntheses tailored for pharmaceutical and materials applications.