Synthesis and antimicrobial activity of some new 1,2-bis-[1,3-thiazolidin-3-yl]ethane derivatives

1,2- Bis -(2-(phenylimino)-4-oxo-1,3-thiazolidin-3-yl)ethane ( 4 ) was synthesized and its reaction with various aldehydes afforded the novel 5-arylidene derivatives 5a - e and 7 . Reaction of compound 4 with phenyl isothiocyanate in the presence of potassium hydroxide, followed by addition of two equivalents of α-halo ketones furnished the corresponding 1,2- bis -[5-(thiazolidin-2-ylidene)thiazolidin-3-yl]ethane derivatives 10 , 14a - c , and 17a , b . The structures of the newly synthesized compounds were established by elemental and spectral analyses. Compounds 5a - e , 7 , 10 , 14a - c and 17a were screened for their antimicrobial activity against eight microorganisms. All compounds showed high antibacterial and antifungal activities against all the test microorganisms except E. coli and C. albicans . The MIC of the active compounds was also evaluated, where; compounds 10 and 17a were more potent active (minimum inhibitory concentration 0.49 and 0.98 μg/mL, respectively) against S. racemosum than Amphotericin B (MIC 1.95 μg/mL).