An improved synthesis of 3,6‐diamino‐1,2,4,5‐tetrazine. I

Treatment of 1,3‐diaminoguanidine monohydrochloride ( 1 ) with 2,4‐pentanedione ( 2 ) in alcohols under carefully controlled conditions gave 3,6‐diamino‐1,2‐dihydro‐1,2,4,5‐tetrazine monohydrochloride ( 3 ) in 45‐50% yields along with 3,5‐dimethyl‐1 H ‐pyrazole ( 4 ) and its hydrochloride 5 . Oxidation of 3 with sodium perborate produced 3,6‐diamino‐1,2,4,5‐tetrazine ( 6 ) in quantitative yield.