Synthesis, in-Vitro Cytotoxicity and Antimicrobial Evaluations of Some Novel Thiazole Based Heterocycles

Condensation of rhodanine (1) with pyrazol-3(2H)-one derivatives (2a-f) gave 5-substituted-2-thioxo-1,3-thiazolidin-4-one derivatives (3a-f). Reaction of compound (1) with 2-arylmethylidene-malononitrile (4a-d) yielded the unexpected derivatives (5a-d). The latter compounds were subjected to cyclization reactions with malononitrile under different basic conditions, hydroxylamine hydrochloride and/or thiourea to furnish the fused thiazole derivatives (6a-d) and (8-10a-d). Coupling of (1) with diazotized aromatic amines (11a-c) in pyridine afforded the arylhydrazones (12a-c). Fusion of latter compounds with malononitrile afforded the thiazolopyridazine derivatives (13a-c). The structures of the newly synthesized compounds were elucidated via spectral data and elemental analyses. The in-vitro cytotoxic activity of compounds (3a-f) against the cell line MCF-7 was evaluated. Also, the synthesized products were investigated for their antibacterial and antifungal activities against six standard organisms including the G⁺ bacteria, Staphylococcus aureus and Bacillus subtilis, G^- bacteria, Escherichia coli and Proteus vulgaris in addition to fungi, Candida albicans and Aspergillus flavus.