ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY https://doi.org/10.14233/ajchem.2017.20925 INTRODUCTION The number of life threatening infections created toward multidrug-resistant has reached an alarming level in hospitals and community. Infections initiated toward these organisms pose a serious challenge to the scientific community and the need for an effective therapy has led to the search for novel medications. There are various naturally animated atoms which hold numerous hetero-atoms, continuously drawn the consi- deration about physicist over those quite some time mostly due to their living vitality. Thiazolidinones are thiazolidine subsidiaries have a place with a large portion every now and again examined moieties. Its vicinity in penicillin might have been those initial distinguishment about its event has did nature [1,2]. 4-Thiazolidinone platform will need to be offered clinched alongside an amount for clinically utilized medications. It needs to be accounted to show different physiological activities. They found uses as antitubercular [3], antimicrobial [4-8], antiinflammatory [9], anticancer [10], antihistamines [11], anticonvulsant [12] and as antiviral agents especially as anti- HIV agents[11,13,14]. It has been extensively reported that the antibacterial activity strongly depended on the nature of substituents at C2 and N3 of thiazolidinone ring. Several methods for the synthesis of 4-thiazolidinones are widely reported in the literature. The main synthetic routes to 1,3- thiazolidin-4-ones involve three components that are an amine, a carbonyl compound and a mercapto acid. The traditional Synthesis and Antimicrobial Activities of Some Novel 2,3-Substituted-1,3-Thiazolidin-4-ones Derived from 2-Amino-1,3-thiazole K. MAHER Department of Chemistry, Faculty of Science, The University of Zakho, 42002 Zakho, Iraq Corresponding author: Tel: + 964 750 3013744, E-mail: maher.ali@uoz.edu.krd; maher-333@hotmail.de Received: 17 July 2017; Accepted: 22 September 2017; Published online: 30 October 2017; AJC-18635 New 2,3-substituted-1,3-thiazolidin-4-one (6a-f) were prepared by cyclocondensation of 2-[6-(4-chlorobenzyloxy)-2-naphthyliden]-4- (4-substituted phenyl)-5-methyl-1,3-thiazole (5a-f) and mercaptoacetic acid in benzene. The synthesized compounds were characterized on the basis of elemental analysis, 1 H NMR, 13 C NMR and FT-IR. The prepared compounds have been screened in vitro against two Gram- positive Staphylococcus aureus, Staphylococcus epidermidis, and two Gram-negative Escherichia coli, Pseudomonas aernuginosa for antibacterial activity and two fungal strains Candida albicans, Candida krusei for antifungal activity using ciprofloxacin, ampicillin and ketoconazole with minimal inhibitory concentration (MIC) value of 10 mcg/L in DMSO. Compounds 6a and 6d showed good antibacterial and antifungal activities compared to reference medications utilized within this study. Keywords: Thiazolidin-4-one, 2-Naphthaldehyde, Schiff Bases, Antimicrobial activities. Asian Journal of Chemistry; Vol. 29, No. 12 (2017), 2794-2798 methods reported can be either a one-pot three-component condensation [15] or in two-step transform. In the current study, 4-thiazolidinones have been synthesized in two steps, the first step included condensation of substituted-2- naphthaldehyde with various substituted aromatic amines and formation of an imine, which undergoes attack by generated sulfur nucleo-phile, followed by intramolecular cyclization on disposal of water in the second step [16-18]. EXPERIMENTAL All the chemicals for the synthesis were purchased from approved venders of different make like Sigma-Aldrich and Merck. Melting point was obtained from Thermal Electro- Melting point apparatus 9300 using capillary tubes. Reactions were carried out under an argon atmosphere with dry solvents under anhydrous conditions. Thin layer chromatography (TLC): Merck Kiese gel 60 F254 on aluminum foil from Macherey- Nagel. Detection was carried out under UV light at 254 and 365 nm. FT-IR spectra were recorded using Perkin-Elmer 1420 (FT-IR) spectrometer. 1 H and 13 C NMR were recorded on Bruker ultra shield 400 MHZ. All NMR spectra present in this work were measured in CDCl 3 solution and TMS as the internal standard. The chemical shifts (δ) are expressed in ppm and Hz, respectively. Element analysis data were performed on a Perkin -Elmer 2400 and elemental analysis of all compounds were in good agreement with the calculated values.