Der Pharma Chemica
Journal for Medicinal Chemistry, Pharmaceutical Chemistry, Pharmaceutical Sciences and Computational Chemistry


Synthesis and Antibacterial Activity of N-substituted-1-benzyl-1H-1,2,3- triazole-carbohydrazide derivatives

Author(s): P. Sreedhar, G. Srinivas and R. Madhusudan Raju

The synthesis of 1-benzyl-1H-1,2,3-triazole-4-carbohydrazides 6a-j data was prepared in four steps from commercially available benzyl bromide 1. Reaction of benzylbromide 1 with sodium azide gave 1- (azidomethyl)benzene 2, which upon condensation with ethyl(triphenylphosphine phosphoranyldene)pyruvate 3 in xylene in sealed tube gave ethyl 1-benzyl-1H-1,2,3-triazole-4-carboxylate 4. Hydrazinolysis of ethylester 4 followed by the condensation with various aromatic / heteroaromatic aldehydes a-j in ethanol at reflux produced 1-benzyl- 1H-1,2,3-triazole-N-substituted hydrazone derivatives 6a-j in quantitative yields. The structural assignment of the synthesized hydrazone derivatives 6a-j was determined by the spectroscopic techniques like 1H NMR, IR and mass spectral. Compounds 6a-j were screened in vitro at a concentration of 250 μg/mL for antibacterial activity against two Gram-positive (Staphylococcus aureus and Staphylococcus pyogenes) and two Gram-negative strains (Escherichia coli and Pseudomonas aeruginosa) with reference to the standard antibacterial drug ciprofloxacin (250 μg/disc). Compounds 6c (Quinaxaline ring), 6d (Imidazole ring), 6e (Pyridine ring) and 6f (Quinoline ring) exhibited significant antibacterial activity.