Synthesis of New 1,2,4-Triazole Derivatives with Expected Biological Activities

To further study novel N-aceyl, N-thiourea and imidazole derivatives were synthesized. We used a multi-step reaction protocol that began with symmetrical 4-amino- 1,2,4-Triazole [I]. The new Schiff base [II] was derived by condensation of compound [I] with 4-aminoacetophenone in Ethanol and some drops from glacial acetic acid as a catalyst, whereas the Schiff base [III] was synthesized by reacting compound [II] with 4-hydroxyacetophenone in ethanol. N- acyl derivative [IV] was prepared by addition reaction of acetyl chloride to azomethine group of Schiff base [III]  in dry benzene. Then, N-thiourea derivative [V] was prepared from reaction of thiourea with N-aceyl derivative [IV] in alkaline solution. The third step involved cyclization reaction of derivative [V] with 2-hydroxy-1,2-diphenylethan-1-one in dimethyl formamide (DMF) to obtain new imidazole derivative [VI]. The synthesized compounds were characterized on the spectroscopic data and their physical properties. Also, we studied the anti-bacterial activity of the prepared compounds against three types of bacteria: Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa, some of which showed best antibacterial activity comparable with Ampicillin, as standard antibiotic. Furthermore, the cytotoxic effect of various concentrations of the prepared compounds [II] and [VI] was investigated against MCF-7 (human breast carcinoma cells), Hep G2 (human liver cancer cell line) and WRL-68 (human hepatic cell line), revealing a moderate activity at 400 μl/ml, which had no effect on the growth of normal WRL-68 cells, and confirmed the safety of using this type of molecules in medications.