1,5-Dihydro-4H-imidazo(4,5-d)-1,2,3-triazin-4-one 2-Azahypoxanthine 4656-86-4 4H-Imidazo(4,5-d)-1,2,3-triazin-4-one, 1,5-dihydro- (9CI) 4H-Imidazo(4,5-d)-v-triazin-4-one, 3,7-dihydro- (8CI) EINECS 225-096-3 NSC 22419