1,2,4-Trihydro-3-imino-7-keto-3H-1,2,4,5-tetrazepine dihydrochloride 3-Amino-2,5-dihydro-6H-1,2,4,5-tetrazepin-6-one dihydrochloride 54978-23-3 6H-1,2,4,5-Tetrazepin-6-one, 3-amino-2,5-dihydro-, dihydrochloride