Synthesis, Characterization and Preliminary Antimicrobial Evaluation with DFT Study of New Thiazole Derivatives

Abstract

Two compounds,[2-amino-4-(4-nitrophenyl)1,3-thiazole],(4) and [2-amino-4-(4-bromo phenyl)1,3-thiazole],(5), were synthesized by refluxing thiourea (1) with each of para-ntirophenacylbromide (2) and para-bromophanacyl bromides (3) respectively, in dry methanol. Then, by reaction of compound [5] with 3,5-dinitrobenzoyl chloride in dimethylformamide (DMF) yielded compound (6) .On the other hand, reaction of compound (4) with chloroacetyl chloride in dry benzene afforded compound (7), which is upon treatment with thiourea in dry methanol, afforded compound (8) . The characterization of the titled compounds were performed utilizing FTIR spectroscopy, 1HNMR, CHNS elemental analysis and by measurements of their physical properties. The synthesized compounds had been screened for their, in vitro preliminary antimicrobial activity against four Gram positive bacteria (Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis and Bacillus pumilus), and four Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis and Klebsiella pneumoniae)and three fungi species: (Saccharomyces cerevisiae, Candida Tropicalis and Candida albicans) using a minimum inhibitory concentration (MIC) of 100 µgml of a derivative in dimethylsulfoxide, by well diffusion method. Compound (6) showed moderate antibacterial activity against some tested Gram positive bacteria (Bacillus pumilus and Bacillus Subtilis) and a moderate antifungal activity towards Candida albicans. Computational study was performed to calculate some of the thermodynamic parameters of synthesized derivatives by using density functional theory (DFT).