Synthesis of some new heterocyclic derivatives from aromatic carbonyl compounds and assessment of their antimicrobial activity

This research work involves synthesis of 18 heterogeneous tetra, penta lateral cyclic compounds (1,3,4-thiadiazole; Thiazolidin-4-one; 1,2,4-Triazol; Carbothioamide; Thiazole-4-one; Azetidin-2-one; Oxazol) compounds. The thiazolidine-4-one was prepared by reaction of p-chlorobenzoic acid with thiosemicarbazide to yield the compound-1, which was treated with p-tolualdehyde to produce compound-2 followed by refluxing (2) with mercaptoacetic acid in dry benzene to yield thiazolidine-4-one compound (3). The reaction of p-nitro benzoic acid with ethanol in the presence of sulphonic acid yielded compound-4 and the reaction of (4) with thiosemicarbazide and 4% NaOH led to produce ring closure giving rise to 1,2,4-triazole (6). The thiosemicarbazone was prepared by the reaction of thiosemicarbazide with different aldehyde (7-9) compounds, A2-substituted-1,3-thiazolidine-4-one were synthesized by the reaction of thiosemicarbazone with chloroacetic acid in the presence of anhydrous sodium acetate yielded (10-12) compounds. The compound-15 was made by the reaction of p-amino benzoic acid with ethyl chloroacetate produced compound-13, then treated with urea to obtain the compound-14 followed by 4-phenyl phenacyl bromide to prepare compound-15. The 2-azetidinone derivative was synthesized by many steps started from cyclization of p-bromoacetophenon with urea in iodine to yield compound-16 which was reacted with p-bromobenzaldehyde to yield compound-17. Schiff base has been treated with chloroacetyl chloride in the presence of catalytic amount of tri-ethyl amine to produce compound-18. All the synthesized compounds were characterized spectroscopically by both FT-IR spectroscopy and by H1-NMR, and C13-NMR for others. Almost all showed matching features and the validity of the proposed structure. The following synthesized compounds (2,3,6,11,13,15,17,18) were also tested against two types of bacteria (Staphylococcus aureus and Escherichia coli and fungus Candida albicans where they showed potential antibacterial and antifungal activities, respectively.