Thiazolidinone Spirocycles: Synthetic Routes and Biological Implications

ABSTRACT Spirocyclic compounds have emerged as privileged scaffolds in medicinal chemistry due to their conformational features such as 3D architecture, sp3 character, and well‐defined stereochemistry. The asymmetric characteristics of spiro compounds significantly contribute to the diverse pharmacological profile. For a long time, spirocyclic compounds have frequently been present in natural products contributing to their therapeutic relevance. Literature reports reveal that heterocycles with N, O, and atoms have yielded bioactive compounds. Among heterocyclic compounds, thiazolidinone represents a wide range of biological activities including anticancer, antimicrobial, antidiabetic, and several others. The presence of NCS linkage along with carbonyl contributes to its therapeutic potential. Combining a thiazolidinone scaffold with a spiro framework can enhance potency by integrating the structural properties of both motifs into a single molecule. Several published studies of spiro‐thiazolidinone derivatives exhibited significant bioactivity against a number of diseases. This review summarizes the common synthetic routes for preparing spiro compounds containing thiazolidinone moiety including N‐alkylation, 1,2‐addition reactions, multicomponent reactions, microwave‐assisted synthesis, and montmorillonite KSF‐mediated approaches, and so forth. Furthermore, the structure–activity relationship (SAR) and biological implications of various spiro‐thiazolidinone derivatives are discussed, emphasizing their promising therapeutic leads for future drug discovery.