A variety of reaction in which hydrazides undergoes and gives the different products which depend upon the nature of hydrazide. Substituted phenyl acetic acid was prepared from corresponding substituted benzaldehyde by azlactone synthesis or by other means. The substituted phenyl acetic acid was converted into their hydrazides by standard procedure reacted with benzoylchloride and the product was heated with phosphorous oxychloride, product was treated with hydrazine under a variety of conditions to furnish unknown 3-substituted benzyl-6-phenyl-1,2-dihydro-1,2,4,5-tetrazine. The structure of tetrazine thus prepared was confirmed by carrying out their synthesis in an alternative method. In alternative manner this consisted of converting the substituted phenyl acetic acid in its corresponding acid chloride reacting it with hydrazine of other benzoic acid followed by treatment with phosphorous oxy-chloride and then cyclizing the resulting product with hydrazine at the same tetrazine. 3-substituted benzyl-6-phenyl-1,2-dihydro1,2,4,5-tetrazine synthesized have been adequately characterized by elemental analysis, melting point and mixed melting point, IR and NMR data.