The interaction between 5-hydrazinyl-substituted 1,2,4-triazines and 2,5-norbornadiene at elevated temperature and pressure (in autoclave) have been studied. The 2-aminopyridines, 5-amino-1,2,4-triazines and 6-unsubstituted pyridines are the products of this reaction. The formation of last two products depends on the substituent at C3 position of the triazine.