Monatsh Chem 139, 691–696 (2008) DOI 10.1007/s00706-007-0794-z Printed in The Netherlands Synthesis, antiinflammatory and antimicrobial activities of some 2,4-dichloro-5-fluorophenyl substituted arylidenetriazolothiazolidinones Mari S. Karthikeyan, Bantwal S. Holla Department of Chemistry, Mangalore University, Mangalagangothri, Karnataka, India Received 6 August 2007; Accepted 31 August 2007; Published online 21 April 2008 # Springer-Verlag 2008 Abstract A series of 2,4-dichloro-5-fluorophenyl substituted arylidenetriazolothiazolidinones were ob- tained by one-pot reaction of 3-(2,4-dichloro-5-fluor- ophenyl)-4H-1,2,4-triazole-5-thiol with substituted benzaldehydes and monochloroacetic acid in the presence of acetic anhydride, acetic acid, and sodium acetate. The structures of the newly synthesized com- pounds were characterized and confirmed by IR, 1 H NMR, mass spectra, and elemental analysis. Com- pounds bearing the 4-methylthiophenyl, 3,4-methyle- nedioxyphenyl, and 2,3,5-trichlorophenyl moiety showed excellent antiinflammatory activity. The anti- microbial screening studies revealed that compounds with 4-anisyl, 4-methylthiophenyl, 3,4-methylene- dioxyphenyl, and 2,3,5-trichlorophenyl at position 5 of the arylidenetriazolothiazolidinone moiety showed excellent activity against all tested strains at 6.25 g cm 3 concentrations. Keywords 3-(2,4-Dichloro-5-fluorophenyl)-4H-1,2,4-tria- zole-5-thiol; One-pot reaction; Arylidenetriazolothiazolidi- nones; Antiinflammatory; Antimicrobial activity. Introduction Thiazolidinone derivatives constitute an important class of heterocyclic compounds. There has been considerable interest in the chemistry of thiazoli- din-4-one ring systems, which is a core structure in various synthetic pharmaceuticals displaying a broad spectrum of biological activities [1]. The thiazo- lidin-4-one ring system also occurs in Nature as actithiazic acid, (()2-(5-carboxypentyl)thiazolidin- 4-one), which is isolated from Streptomyces strains [2]. Thiazolidinone derivatives are known to exhibit diverse bioactivities such as anticonvulsant [3], anti- diarrheal [4], antimicrobial [5], antidiabetic [6], cy- cloxygenase inhibitory [7], Ca 2þ channel blocker [8], cardioprotective [9], anticancer [10], anti HIV [11], and tumor necrosis factor--antagonist activities [12]. 1,2,4-Triazoles represent an overwhelming and rap- id developing field in modern heterocyclic chemistry. From literature, it is predictable that 1,2,4-triazoles represent important pharmacophores, and have a wide range of therapeutic properties. They play a vital role as medicinal agents due to different biological activi- ties and lot of work might be carried out on this moiety for obtaining better therapeutic molecules. At present several triazole bearing compounds like Flutrox, Nefazodone, Trazodone, Triazoledione, etc., are used in modern medicine. A degree of respectability has been bestowed for 1,2,4-triazole derivatives due to their antibacterial, antifungal [13], antitubercular [14], and anticancer [15] properties. Certain 1,2,4-triazoles also find applications in the preparation of photograph- ic plates, polymers, and as analytical agents [16]. The importance of fluorine containing compounds in general, and heterocyclic in particular, has initiated active research on fluorine containing heterocycles. Correspondence: Mari Sithambaram Karthikeyan, Department of Chemistry, Mangalore University, Mangalagangothri 574199, Karnataka, India. E-mail: karthims02@rediffmail.com