Reaction of 5-hydrazinyl-substituted 1,2,4-triazines and 2,5-norbornadiene at elevated pressure and temperature (in autoclave) has been studied; the reaction yields 2-aminopyridines, 5-amino-1,2,4,-triazines, and 6-unsubstituted pyridines (formation of one of two latter products is dependent on the nature of substituent in the C3 position of triazine).