Muhammad Haroon et al., J.Chem.Soc.Pak., Vol. 39, No. 04, 2017 614 Synthesis, Crystal Structure and Biological Evaluation of 5-Arylidine derivatives of 3-Phenyl-2-(phenylimino)thiazolidin-4-one 1 Muhammad Haroon, 1 Tashfeen Akhtar * , 2 Muhammad Nawaz Tahir, 3 Imran Ali and 4 Shahid Hameed 1 Department of Chemistry, Mirpur University of Science and Technology (MUST), 10250 Mirpur Azad Jammu & Kashmir, Pakistan. 2 Department of Physics, University of Sargodha, Punjab, Pakistan. 3 Department of Biotechnology, Mirpur University of Science and Technology (MUST), 10250 Mirpur Azad Jammu & Kashmir, Pakistan. 4 Department of Chemistry, Quaid-i-Azam University Islamabad, 45320, Pakistan. tashfeenchem@must.edu.pk* (Received on 14 th March 2016, accepted in revised form 2 nd February 2017) Summary: Arylidene derivatives of 3-phenyl-2-(phenylimino)thiazolidin-4-ones are prepared by its condensation with respective aromatic aldehydes. The structures of synthesized compounds are established using FTIR, 13 C-NMR, 1 H-NMR, mass spectrometry. The structure of 5-(furan-2- ylmethylene)-3-phenyl-2-(phenylimino)thiazolidin-4-one (2c) is also confirmed by X-rays crystallography. The compounds were examined for their antibacterial and enzyme inhibitory effects. Some of the compounds have shown promising activities. Keywords: Thiazolidinones, Thiourea, Arylidene, Antimicrobial, X-ray crystallography. Introduction Thiazolidinone is an important pharmacophore exhibiting various pharmacological activities depending on the substituents and the substitution pattern. Thiazolidin-4-ones are saturated analogues of thiazole-3(4H)-one. Thiazolidinones are seen as an important target to combat the problem of multi-drug resistant pathogens causing infectious diseases. Thiazolidin-4-ones exhibit anti-bacterial [1, 2], anti-fungal [3, 4] anti-inflammatory [5], anti- mycobacterial [6], anti-Toxoplasma gondii [7], anti- cancer [8], CFTR inhibitor [9] and anti-convulsant [10] properties. Various methods are reported for the synthesis of thiazolidin-4-one. The method involving the condensation of 1,3-disubstitued thiourea and chloroacetyl chloride showed that the product obtained in this reaction is actually thiazolidin-4-one and not thiohydantoins [11]. The diversity associated with thiazolidin-4- ones prompted us to synthesize some derivatives for potent biological activities. 3-Phenyl-2- (phenylimino)thiazolidin-4-one was selected as an intermediate and condensed with different aldehydes to get 5-aryliden-3-phenyl-2-(phenylimino) thiazolidin-4-one. The compounds were characterized by spectroscopic techniques and X-rays crystallography. The compounds were tested for their anti-microbial and enzyme inhibition potential. Experimental Material and Methods The solvents, reagents and substrates used were obtained from different brands and of high purity grade and utilized without any purification. Silica gel 60 HF 254 pre-coated aluminum sheets (Merck) were used for thin layer chromatography (TLC). Gallen Kemp melting point apparatus used for melting point determination and are uncorrected. FTIR spectra that were recorded on Thermo Scientific Nicolet 6700 FTIR Spectrophotometer using ATR. 1 H and 13 C-NMR spectrum was recorded on Bruker Avance 300 MHz spectrometer; chemical shifts are reported in δ (ppm) and calibrated with reference to the residual signals of the solvents. X-ray diffractions are recorded on Bruker Kappa APEX II CCD Diffractometer. Synthesis of 3-phenyl-2-(phenylimino)thiazolidin-4- one (1) [12] 1,3-Diphenylthiourea (0.01mol), ethylbromoacetate (0.01mol) and sodium acetate (0.2mol) were heated under refluxed for 6 hs in methanol (30ml). The reaction mixture was poured into cold water, a white solid separated, which was filtered and washed with excess of water. Yield: 87%; m.p.: 286 – 288 o C; IR (ATR, cm -1 ): λ max 3048 (CH Ar), 1720 (C=O), 1371 (C – N), 1269 (C-S); 1 H-NMR (300 MHz, DMSO): δ 4.17 (2H, s, CH 2 ), 7.53 (2H, m, Ar), 7.43 (3H, t, Ar, J =8.4 Hz), 7.34 (2H, m, Ar), 7.1 (1H, t, Ar, J =7.5 Hz), 6.88 (2H, d, Ar, J =8.4 Hz); 13 C-NMR (75 MHz, DMSO):δ 32.93 (-CH 2 -), 121, 124, 128, 129, 135, * To whom all correspondence should be addressed.