1,2,4-Trihydro-3-imino-6-methyl-7-keto-3H-1,2,4,5-tetrazepine hydrochloride 3-Amino-2,5-dihydro-7-methyl-6H-1,2,4,5-tetrazepin-6-one monohydrochloride 54978-24-4 6H-1,2,4,5-Tetrazepin-6-one, 3-amino-2,5-dihydro-7-methyl-, monohydrochloride