Synthesis of New Thiazole, Bithiazolidinone and Pyrano[2,3-d ]thiazole Derivatives as Potential Antimicrobial Agents

In an attempt to find a new class of antimicrobial agents, a series of thiazole derivatives containing furan moiety 3, 7, 8a,b, 10a-c and 12 were prepared via the reaction of 2-cyano-N-(furan-2-ylmethyl)acetamide (1) with phenyl isothiocyanate and α-halocarbonyl compounds. Also, many bithiazolidinone and pyranothiazole derivatives were synthesized through interaction of thiazolidinone 7 with appropriate electrophilic reagents. These compounds were screened for their antibacterial and antifungal activity. Among the synthesized compounds, thiazole derivatives 23a and 23b were equipotent to gentamycin against K. pneumonia (MIC 0.49 μg/mL), and showed in vitro antifungal activity equipotent to amphotericin B versus A. fumigatus (MIC 0.98 μg/mL), A. clavatus (MIC 0.98 μg/mL) and G. candidium (MIC 0.49 μg/mL). Also, bithiazolidinones 14 and 15 were equipotent to amphotericin B in inhibiting the growth of A. clavatus (MIC 0.98 μg/mL) and G. candidium (MIC 0.49 μg/mL). Structures of the newly synthesized compounds were established by elemental analysis and spectral data.