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Abstract:
3-(2-amino-3,5-dibromophnyl) - 4- amino 5- mercapto - 1,2,4 - triazole (6) when condensed with substituted aryl/aryloxy/ hetero aryl acids in presence of pocl3 gave 3 -(2-amino-3,5 dibromophenyl)-6-substituted (3,4-b) (1,3,4) triazolothiadiazoles (7a1 - a25).The compound 6 when condensed with dicarboxylic acids like oxalic acid, succinic acid and tartaric acid in presence of pocl3 yielded 6,6 bis- 3-(2-amino-3,5 - dibromo phenyl) - 1,2,4 triazolo (3,4-b) (1,3,4) thia diazoles (8,9 & 10). The structures of the newly synthesized compounds have been established on the basis of their spectral data. The broad spectrum of activity exhibited by triazoles and their N-bridged analogues prompted us to evaluate their antibacterial, antifungal, antitubercular and anticancer activity. Few compounds showed significant antitubercular and anticancer activity. Majority of the compounds exhibited excellent antibacterial and antifungal activity.
Key Words: Triazolothiadiazole, antimicrobial, antitubercular, anticancer.
Introduction
Heterocyclic compounds containing 1,2,4-triazole and thiadiazole nucleus possess a diversity of useful biological effects. Further it was also reported that substituted 1,2,4 triazoles and their Nbridged heterocycles have received considerable attention during past two decades as they are endowed with variety of biological activities and have a wide range of therapeutic properties1-4. Various 3- substituted 4-amino 5-mercapto -1,2,4-triazoles have been studied extensively for the past several years because of their broad spectrum of biological activity and variety of medicinal applications5-8. The amino and mercapto groups of these compounds serve as readily accessible ncleophilic centres for the preparation of N-bridged heterocycles. The 1,3,4-thiadiazoles which display diverse biological activities, possible due to the presence of toxophoric>N-C-S moiety. The 1,2,4 triazolo-(3,4 -b) - 1,3,4 thiadiozole derivatives obtained by fusing biolabile 1,2,4trizole and 1,3,4-thiodiazole rings together are reported to possess antibacterial, antifungal, antitubercular, anti-inflammatory, analgesic, antiviral plant growth regulatory properties. Further it has been reported that many biological active natural and synthetic products have interesting molecular symmetry. Recently some bistriazole derivatives endowed with excellent biological activity have also been reported9-10. Prompted by the above facts and as part of our programme aimed at developing new biologically active compounds, we designed the synthesis and biological evaluation of series of novel 3-(2-amino-3,5- dibromo phenyl)-6-substituted (3,4b) (1, 3, 4) - triazole thiadiozoles (7a1 - a25) and 6,6 -bis-3(2- amino-3,5-dibromo phenyl)-1,2,4-triazolo (3,4b) (1, 3, 4) thiadiazoles8-11. (8,9 & 10) Apart from their chemical interest these compounds could...