Functionality of 4-amino-5-hydrazinyl-4H-1,2,4-triazole-3-thiol in synthesis of new fused triazolotriazines and triazolotriazepines of potential gram negative antibacterial activity

4-Amino-5-hydrazinyl-4H-1,2,4-triazole-3-thiol reacted with dimethyl acetylene-dicarboxylate, ethyl propiolate, (E)-1,2-dibenzoylethylene, 2-(1,3-dioxo-1H-inden-2(3H)-ylidene) malononitrile, 2,3-dichloro-1,4-naphthoquinone, 2,3,5,6-tetrachloro-1,4-benzoquinone and 3,4,5,6-tetrachloro-1,2-benzoquinone to give various novel heterocylic compounds. Seven chemically synthesised compounds were screened for their in vitro antimicrobial activity against different strains of microorganisms. Most of the tested compounds exhibited an excellent antibacterial activity against Gram negative bacteria including Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa compared to the activity of ciprofloxacin.