Two novel 1,5-benzodiazepin-2-one derivatives were prepared and characterized using different spectroscopic techniques and single crystal X-ray diffraction. The DFT-B3LYP study was also performed to investigate differences in the electric properties. The in vitro antibacterial activity of three 1,5-benzodiazepine heterocyclic compounds was investigated against Escherichia coli ATCC 4157, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Streptococcus faecalis ATCC 29212 bacterial strains. The results obtained showed the remarkable activity of compound 3 against S. faecalis and of compound 5 against E. coli, S. Aureus and S. faecalis with MICs of 5 mu g / mL compared to the standard reference. Molecular docking was performed to position compounds 3, 4 and 5 into the S. aureus and E. coli active site to rationalize the probable mode of action, binding affinity, and orientation of the molecules at the active site of receptor. (C) 2021 Elsevier B.V. All rights reserved.