SYNTHESIS OF 1,2,4,5-TETRAZINES

1-[S-Benzylarylthiocarbamoyl]-2-(phenylcarbamyol) hydrazines, (Ila-e) have been obtained by the benzylation of 1-(arylthiocarbamoyl)-2-(phen ylcarbamoyl) hydrazines (la-e), which in turn were obtained by condens ation of arylisothiocyanates with 4-substituted phenylcarbamidohydrazi ne. The compounds, (la-e) and (la-e) on oxidative cyclization with mol ecular bromine resulted in the formation of corresponding 1-aryl-2-phe nyl-3-oxo-6-thiono-1 ,2,4,5-tetrahydro-s-tetrazines (IVa-e) and nyl-3- oxo-6-benzylthio-1,2,4-trihydro-s-tetrazines (IIla-e) respectively.