An improved synthesis of 3,6‐diamino‐1,2,4,5‐tetrazine. II. From triaminoguanidine and 2,4‐pentanedione

A new synthesis for the title compound that gives an 80% overall yield was developed. Treatment of triaminoguanidine monohydrochloride ( 1 ) with 2,4‐pentanedione ( 2 ) gave 3,6‐bis(3,5‐dimethylpyrazol‐1‐yl)‐1,2‐dihydro‐1,2,4,5‐tetrazine ( 3 ) in 80–85% yield. Oxidation of 3 with nitric oxide or nitrogen dioxide to 3,6‐bis(3,5‐dimethyylpyrazol‐1‐yl)‐1,2,4,5‐tetrazine ( 4 ) followed by ammonolysis of 4 gave 3,6‐diamino‐1,2,4,5‐tetrazine ( 5 ) in guantitatively yields.