Mamane, V. et al. published their research in Journal of Organic Chemistry in 2016 | CAS: 13472-81-6

3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.SDS of cas: 13472-81-6

Chiral Hexahalogenated 4,4′-Bipyridines was written by Mamane, V.;Peluso, P.;Aubert, E.;Cossu, S.;Pale, P.. And the article was included in Journal of Organic Chemistry in 2016.SDS of cas: 13472-81-6 This article mentions the following:

The preparation of 27 isomers of chiral hexahalogeno-4,4′-bipyridines by means of two complementary methods is described. The first one is convergent and based on the LDA-induced 4,4′-dimerization of trihalopyridines, whereas the second method is divergent and achieved through regioselective halogenation reactions of 4,4′-bipyridine-2,2′-diones. Iodine in 2,2′-positions of the 4,4′-bipyridines was introduced by a copper-catalyzed Finkelstein reaction (Buchwald procedure) performed on 2,2′-dibromo derivatives Selected compounds of this new family of atropisomeric 4,4′-bipyridines were enantiosepd. by high performance liquid chromatog. on chiral stationary phases, and the absolute configurations of the separated enantiomers were assigned by using X-ray diffraction anal. The latter revealed that various halogen bond types are responsible for crystal cohesion. In the experiment, the researchers used many compounds, for example, 3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6SDS of cas: 13472-81-6).

3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.SDS of cas: 13472-81-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem