Butler, Richard N. published the artcileStereoisomerization in heterocyclic hydrazones derived from 2-acylpyridines and their oxidative cyclization with mercury(II) acetate and lead tetraacetate to fused 1,2,4-triazoles and 1,2,3-triazolium systems, Recommanded Product: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, the publication is Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) (1984), 2109-16, database is CAplus.
Fourteen hydrazones I (R = H, Me, Ph; R1 = 2-pyridyl, 4-O2NC6H4, Ph, 4-BrC6H4, 4-MeOC6H4, 4-MeC6H4), prepared by coupling 2-formyl-, -benzoyl-, or -acetylpyridine with H2NNHR1 (R1 as before), were isolated predominantly as E isomers, when the acyl substituent R was small (H = Me). When R = Ph, significant yield of Z isomers containing an intramol. H bond were also obtained. The structure of E-I (R = R1 = Ph) was determined by x-ray crystallog. Oxidation reactions of I were not configuration dependent contrary to the report of R. Kuhn and W. Munzig (1952). A common metallo intermediate II, was obtained by oxidation of E– and Z–I (R = H, R1 = 2-pyridyl) with Hg(OAc)2. In Pb(OAc)4 oxidation of the hydrazones, the product controlling factor was the nature of the methine substituent R. For the ketone derivatives I (R â?H), oxidation to fused 1,2,3-triazolium systems occurred via a 5-exo–tet cyclization with E- and Z-hydrazones, whereas for aldehyde systems, I (R = H), the oxidation involved dehydration to a nitrilimine and gave products by solvent addition or a 5-endo–dig cyclization to fused 1,2,4-triazolo systems. Thus, Pb(OAc)4 oxidation of E– or Z–I (R = Ph, R1 = 4-O2NC6H4) gave 80% triazolopyridinium III, whereas similar oxidation of E– or Z–I (R = H, R1 = 2-pyridyl) gave 73-86% triazolopyridine IV.
Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C11H10N4, Recommanded Product: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem