Solventless synthesis of new 4,5-disubstituted 1,2,3-selenadiazole derivatives and their antimicrobial studies

Two novel, namely 5-Phenyl-4-methyl-1, 2, 3-selenadiazole (5h) and 4-Phenyl-5-propyl-1, 2, 3-selenadiazole (5i) along with several other aliphatic and aromatic series of 1,2,3-selenadiazoles were synthesized at room temperature in one step under solventless conditions from the corresponding semicarbazones. All compounds were thoroughly characterized by various spectroscopic tools. The synthesized new and reported 1,2,3-selenadiazoles were found active against bacterial as well as fungal stains when screened for their antimicrobial activity against various pathogenic bacteria and fungi using agar disc diffusion as well as agar well diffusion method. Almost all selenadiazoles showed better antibacterial properties in comparison to established antibiotics like tetracycline. 4-ethyl-5-methyl-1,2,3-selenadiazole showed higher antimicrobial activity amongst the tested selenadiazoles.