Synthesis and antimicrobial activity of novel thienopyrimidine linked rhodanine derivatives

This work presents the preparation of a new series of N-(substituted phenyl)-2-(4-oxo-5-(4-(thieno[ 2,3-d]-pyrimidin-4-yloxy) benzylidene)-2-thioxothiazolidin-3-yl) acetamide derivatives (8a-8l). A condensation reaction of thienopyrimidin-2-thioxothiazolidin-4-one derivative (5) with various 2-chloro-N-phenylacetamides (7a-7l) was employed to afford the new thienopyrimidine tagged rhodanine derivatives under acetone solvent in the presence of potassium carbonate (K2CO3). All of the novel target molecules were characterized by IR, H-1 NMR, C-13 NMR, and LC-MS spectral analyses and were screened for their in vitro antimicrobial activity by using the broth dilution method. Compounds 8c, 8g, and 8h found to have antibacterial potency against E. coli, B. subtilis, B. cereus, and K. pneumonia with minimum inhibitory concentrations (MICs) of 3.25-6.25 mu g/mL compared with the standard Gentamicin. Compounds 8c and 8f demonstrated better antifungal potency (MIC = 3.25-6.25 mu g/mL) against A. flavus, A. niger, P. marneffei, and C. albicans when compared with Fluconazole.