Synthesis of 3,6–Disubstituted Tetrahydro– S –triazolo[3,4–b][1,3,5]thiadiazines

Ten novel 3,6-disubstituted tetrahydro-S-triazolo[3,4-b][1,3,5]thiadiazines 2 have been synthesized by the double Mannich reaction of 3-aryl-5-mercapto-1,2,4-triazole with various aromatic amines and formaldehyde in the presence of ethanol-HCl solution. The structure of these compounds was determined by elemental analysis, IR, NMR and MS. Their antibacterial activities against E. coli, B. bob and S. aureus have been tested.