The oxidation of s-triazolo[4,3-b]pyridazines with selenium dioxide was written by Iwao, Masatomo;Kuraishi, Tsukasa. And the article was included in Journal of Heterocyclic Chemistry in 1976.COA of Formula: C5H3ClN4O This article mentions the following:
The s-triazolo[4,3-b]pyridazines I (R = Me, MeO, Cl, H, R1 = H; R = Cl, R1 = AcNH) were oxidized to the s-triazolo[4,3-b]pyridazin-3-ones II with SeO2 in PhNO2 at 160-165° for 1-2 hr in 30-40% yields. In the experiment, the researchers used many compounds, for example, 6-Chloro-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one (cas: 33050-32-7COA of Formula: C5H3ClN4O).
6-Chloro-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one (cas: 33050-32-7) belongs to pyridazine derivatives. The pyridazine structure is a popular pharmacophore which is found within a number of herbicides such as credazine, pyridafol and pyridate. Pyridazine is bioavailable (especially in the CNS) and can reduce toxicity. Pyridazine is a component of several drug molecules, and the pyridazine pharmacophore has contributed to a variety of pharmacologically active compounds.COA of Formula: C5H3ClN4O
Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem