Synthesis and biological evaluation of dihydroindeno and indeno [1,2-e] [1,2,4]triazolo [3,4-b] [1,3,4]thiadiazines as antimicrobial agents

Two series of compounds namely, dihydroindeno and indeno [1,2-e] [1,2,4]triazolo [3,4-b] [1,3,4]thiadizines (9a–l & 11a-l) were synthesized by cyclocondensation between α-bromoindanones (7a–b) or/and α,α-dibromoindanones (8a–b) and various 3-alkyl/aryl-4-amino-5-mercapto-1,2,4-s-triazoles (3a–f) in methanol with an aim to explore their effect on in vitro growth of microorganism causing microbial infection. In vitro antibacterial activity was performed against four strains namely, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and antifungal activity against three fungal strains namely, Aspergillus niger, Aspergillus flavus, Penicillium species. Of all the compounds screened for activity some of the compounds were associated with considerably higher antibacterial and antifungal activity than commercial antibiotics.

Graphical abstractVarious new triazolothiadiazines derivatives were designed and synthesized for antimicrobial evaluations. Some of these compounds were found to be associated with promising biological activity than standard drug.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Twenty four new compounds triazolo [3,4-b] [1,3,4]thiadiazines were synthesized. ► In vitro antibacterial and antifungal activity was investigated. ► Some of these compounds showed significant biological activity than standard drug.