Haider, Norbert published the artcilePyridazines. XXXV. Preparation of some novel pyrimido[4,5-c]pyridazine derivatives from 3-(alkylamino)- and 3-(arylamino)-4-pyridazinecarboxamides, COA of Formula: C5H4N4, the publication is Journal of Heterocyclic Chemistry (1988), 25(1), 119-24, database is CAplus.
Pyrimido[4,5-c]pyridazinediones I (R = Ph, PhCH2; R1R2 = O), pyrimido[4,5-c]pyridazinones II (R = Ph, PhCH2; R3 = H, Me, Et), and dihydropyrimido[4,5-c]pyridazinones I (R = Ph, PhCH2, Me2CH; R1 = H, R2 = Ph, 3-pyridyl) were prepared from 3-chloro-4-pyridazinecarbonitrile III (R4 = Cl) via amino carbonitriles III (R4 = NHR) and amino carboxamides. In addition, III (R4 = NH2) was prepared from III (R4 = Cl), via the tetrazolo[1,5-b]pyridazine IV as the key intermediate.
Journal of Heterocyclic Chemistry published new progress about 119581-52-1. 119581-52-1 belongs to pyridazine, auxiliary class Pyridazine,Nitrile,Amine, name is 3-Aminopyridazine-4-carbonitrile, and the molecular formula is C5H4N4, COA of Formula: C5H4N4.
Referemce:
https://en.wikipedia.org/wiki/Pyridazine,
Pyridazine | C4H4N2 – PubChem