Reaction of aromatic N-oxides with dipolarophiles. III. Cycloadditions of substituted phenyl isocyanates to 3,5-dimethyl and 3,5-dibromopyridine N-oxides and x-ray crystal structures of the isomeric cycloadducts was written by Hisano, Takuzo;Ichikawa, Masataka;Matsuoka, Toshikazu;Hagiwara, Hisao;Muraoka, Keiji;Komori, Tetsuya;Harano, Kazunobu;Ida, Yoshiteru;Christensen, Arild T.. And the article was included in Chemical & Pharmaceutical Bulletin in 1979.COA of Formula: C7H9NO This article mentions the following:
Three β-substituted pyridine N-oxides were subjected to 1,3-dipolar cycloaddition with substituted Ph isocyanates. 3-Methyl- and 3,5-dimethyl-pyridine N-oxide afforded the 2,3-dihydropyridine derivatives, and the 3,5-dibromo compound afforded a 2,3-dihydro-2-oxo-oxazolo[4,5-b]pyridine by the elimination of HBr from the 2,3-dihydropyridine. The presence of an o-substituent or NO2 in the Ph isocyanate resulted in a reduced cycloaddition yield. The structures of the 2,3-dihydropyridine adducts were determined by X-ray crystallog. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8COA of Formula: C7H9NO).
3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) belongs to pyridine derivatives. Pyridines are an important class of heterocycles and occur in polysubstituted forms in many naturally occurring biologically active compounds, drug molecules and chiral ligands. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.COA of Formula: C7H9NO