Heterocyclic systems containing bridgehead nitrogen atom:: Synthesis and biological activity evaluation of s-triazolo[3,4-b] [1,3,4]thiadiazoles,s-triazolo[3,4-b][1,3,4]-thiadiazines and s-triazolo [3′,4′:2,3][1,3,4]thiadiazino[5,6-b]quinoxaline

The condensation of 3-p-(t-butylphenyl)-4-amino-5-mercapto-s-triazole 1, independently, with chloroacetic acid, alpha -haloketones, benzoin, 2,3-dichloroquinoxaline, aromatic carboxylic acids, carbon disulphide and aromatic carboxaldehydes furnishes in one step the cyclic products, 3-p-(t-butylphenyl)-7H-s-triazolo[3,4-b][1,3,4]thiadiazin-6(5H)-one 2, 6-aryl-3-p-(t-butylphenyl)-7H-s-triazolo[3,4-b][1,3,4]thiadiazine 4, 3-p-(t-butylphenyl)-6,7-diphenyl-5H-s-triazolo[3,4,b][1,3,4]thiadiazine 4, 3-p-(t-butylphenyl)-5H-s-triazolo[3',4':2,3,4]thiadiazino[5,6-b] quinoxaline 5, 3-p-(t-butylphenyl)-6-aryl-s-triazolo[3,4-b] [1,3,4]thiadiazoles 6, 3-p-(t-butylphenyl)-s-triazolo[3,4-b][1,3,4]thiadiazole-6(5H)-thione 7 and 6-aryl-5,6-dihydro-3-p-(t-butylphenyl)-s-triazolo[3,4-b][1,3,4]thiadiazoles 8 respectively. The structures have been established on the basis of elemental analysis and spectral data. The antibacterial and antifungal activity of some of the compounds have also been evaluated.