A regiospecific reaction of pyridazines with vicarious nucleophilic substitution via their dicyanomethylide derivatives was written by Itoh, Takashi;Matsuya, Yuji;Nagata, Kazuhiro;Okada, Mamiko;Ohsawa, Akio. And the article was included in Journal of the Chemical Society, Chemical Communications in 1995.Application In Synthesis of 3-Methoxypyridazine This article mentions the following:
The phenyl(or p-tolyl)sulfonylmethyl group is introduced with complete regiospecificity to the C-4 position of 3-substituted pyridazines using vicarious nucleophilic substitution of pyridazinium dicyanomethylides. In the experiment, the researchers used many compounds, for example, 3-Methoxypyridazine (cas: 19064-65-4Application In Synthesis of 3-Methoxypyridazine).
3-Methoxypyridazine (cas: 19064-65-4) belongs to pyridazine derivatives. Pyridazines are rare in nature, possibly reflecting the scarcity of naturally occurring hydrazines, common building blocks for the synthesis of these heterocycles. The unsubstituted pyridazines are more resistant to eletrophilic substitution due to the nature of withdrawal of electron density from the ring by two heteroatoms, while the related electron deficiency of the ring makes pyridazine more easily attacked by nucleophiles.Application In Synthesis of 3-Methoxypyridazine
Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem