(Z)-3′-(3-Chloro-4-fluorophenyl)-5-fluoro-5′-((6-methoxypyridin-3-yl)methylene)spiro[indoline-3,2′-thiazolidine]-2,4′-dione

A novel spiro[indoline-3,2′-thiazolidine]-2,4′-dione derivative incorporating 3-chloro-4-fluorophenyl and 6-methoxypyridin-3-yl fragments was synthesized and characterized. The synthetic route involved a two-step procedure, including the preparation of the spirocyclic scaffold via cyclocondensation of 5-fluoroisatin with 3-chloro-4-fluoroaniline in the presence of mercaptoacetic acid, followed by Knoevenagel condensation with 6-methoxypyridine-3-carbaldehyde. The reactions were carried out under reflux conditions and afforded the desired product in a satisfactory yield after purification by recrystallization. The structure of the synthesized compound was confirmed by 1H and 13C NMR spectroscopy, LC–MS analysis, FT-IR and elemental analysis, all of which were consistent with the proposed molecular structure. The presence of multiple pharmacologically relevant heterocyclic motifs within a single framework suggests that this compound may serve as a useful scaffold for further biological evaluation.