Synthesis of 1,2,4,5-tetrazines

Abstract

1-[S-Benzylarylthiocarbamoyl]-2-(phenylcarbamoyl) hydrazines, (IIa-e) have been obtained by the benzylation of 1-(arylthiocarbamoyl)-2-(phenylcarbamoyl) hydrazines (Ia-e), which in turn were obtained by condensation of arylisothiocyanates with 4-substituted phenylcarbamidohydrazine. The compounds, (Ia-e) and (IIa-e) on oxidative cyclization with molecular bromine resulted in the formation of corresponding 1-aryl-2-phenyl-3-oxo-6-thiono-1,2,4,5-tetrahydro-s-tetrazines (IVa-e) and 1-aryl-2-phenyl-3-oxo-6-benzylthio-1,2,4-trihydro-s-tetrazines (IIIa-e) respectively.