Investigation into the regioisomeric composition of some fused tetrazoles

Document Type: Original Paper


Departmentof Chemistry, School of Sciences, Islamic Azad University, Ahvaz Branch, Ahvaz


Treatment of 7-chloro-1-phenylpyrimido[4,5-e][1,3,4]thiadiazines with hydrazine in boiling ethanol gave corresponding7-hydrazinyl derivatives. Diazotization of the latter compounds acheived a mixture of 5H-tetrazolo[1',5':1,2]pyrimido[4,5-e][1,3,4]thiadiazine and 9H-tetrazolo[5',1':2,3]pyrimido[4,5-e][1,3,4]thiadiazines. Ratio of these two group of products determined by 1HNMR studies and no significant preference was observed for their formation. Efforts for separation of the products were unsuccessful and its reason is discussed.