Synthesis, Characterization and in vitro Antibacterial Activity of Novel 1,2,4-Triazine and 1,2-Diazepine Derivatives

In this work we describe a simple method to synthesis novel 3-[(pyridine-2-ylamino)methyl]-1,6-dihydro-1,2,4-triazine-5(2H)-one (3) and 1-(N-pyridine-2-ylglycyl)-1,2-diazepine-3,7-dione (4). Firstly, adding ethyl chloroacetate to a solution of KOH and 2-amionpyrdine and refluxed in absolute ethanol for 5 hours afforded the target ethyl-N-pyridin-2-ylglycinate (1), then refluxing of compound (1) with hydrazine hydrate in absolute ethanol for 6 hours yield 2-(pyridine-2-ylamino)acetohydrazide (2). Chloroacetamid and glutaric acid were refluxed with compound (2) in absolute ethanol for 20 and 21 hours to afford the compounds 3-[(pyridine-2-ylamino)methyl]-1,6-dihydro-1,2,4-triazine-5(2H)-one (3) and 1-(N-pyridine-2-ylglycyl)-1,2-diazepine-3,7-dione (4), respectively. Structures of the synthesized compounds were supported by means of FTIR, CHN elemental analysis, and NMR (1H, 13C) spectroscopic analysis. The synthesized compounds were evaluated for their in vitro antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus cereus, and Enterococcus faecalis. The inhibition zones were measured, expressed in mm, and the minimum inhibitory concentration (MIC) is reported in mu g/mL. The results show that compounds (3) and (4) have a significant antimicrobial activity with the highest MIC value against all tested bacteria.