Synthesis and biological activity of 1,2,4-triazole derivatives containingtriazolo-thiadiazole and triazolo-thiadiazolidine ring systems

Various 3-substituted-5-pyridyl-1,2,4-triazolo (3,4-b) (1,3,4) thiadiazoles (4a-l) and 4-pyridoyl-3-substituted-5-thiono-1,2,4-triazolo (3,4-b) (1,3,4 ) thiadiazolidines (5a-l) were synthesized by the reaction of 4-(N-pyridyl carboxamido)-5-mercapto-3-substituted-1,2,4-triazoles (3a-l) with concentra ted sulphuric acid and carbon disulphide respectively. These compounds were screened for their antimicrobial activities.