Synthesis and antibacterial activity of some 5-guanylhydrazone/thiocyanato-6-arylimidazo[2,1-b]-1,3,4-thiadiazole-2-sulfonamide derivatives

6-Arylimidazo[2,1-b]-1,3,4-thiadiazole-2-sulfonamides 3 on Vilsmeier-Haak r eaction produced 5-formyl-6-arylimidazo[2, 1-b]1,3,3-thiadiazole-2-[N-(dime thylaminomethino)]sulfonamides 4, while 3 on treatment with potassium thioc yanate in the presence of bromine in acetic acid produced 5-thiocyanato-2-s ulfonamides 6. Interaction of 4 with aminoguanidine hydrochloride in ethano l produced the corresponding 5-guanylhydrazone derivatives 5. Compounds 5 a nd 6 showed a high degree of antibacterial activity against both Escherichi a coli and Staphylococcus aureus comparable to that of sulfamethoxazole and Norfloxacin. However, they were found to show moderate activity against Sa lmonella typhi, Pseudomonas aeruginosa and Pneumococci. (C) 2000 Editions s cientifiques et medicales Elsevier SAS.