Synthesis and Investigation of the Antibacterial Activity of New Tris-Thiourea Derivatives

An efficient procedure for the preparation of symmetrical tris-thiourea derivatives (5a – 5h) by means of one-pot condensation reaction between available benzoyl chlorides (1a –1h) with potassium thiocyanate (2) and melamine (4) under reflux conditions is presented. All the synthesized tris-thioureas were evaluated for their biological activities against a group of Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli) bacteria. The synthesized compounds showed no activity against P. aeruginosa. All compounds exhibited excellent antibacterial activity against indicated bacterial strains. The new products were characterized using FT-IR, 1H and 13C NMR spectra, and elemental analysis.