The pyridine ring system comes about in the structures of many natural products, pharmaceutical and agrochemical compounds, and other commercial substances. An extensive varieties of synthetic methods have been developed, both for construction of the pyridine ring and for its substitution. The chemistry and applications of pyridine compounds have recently received much attention due to their usefulness as synthetic intermediates and their biological importance.

Some of the pyridine compounds are usable for mammals including human beings in preventing and treating various diseases caused by helicobacter. The compounds are also useful in preventing the reoccurrence of ulcer, controlling vomiting and preventing and treating non-ulcer dyspepsia and tumors such as gastric cancer. These compounds also have inhibitory effects on gastric hydrochloric acid secretion, anti-ulcer effects, protective effects on gastrointestinal cells, anti-diarrhea effects, etc. Hence these are useful as preventives and remedies for digestive diseases such as gastric ulcer, duodenal ulcer, gastritis, diarrhea and colon inflammation.

Pyridine N-oxides

The chemistry and applications of N-oxides have recently received much attention due to their usefulness as synthetic intermediates and their biological importance. Heterocyclic N-oxides are also useful as protecting groups, auxiliary agents, oxidants, ligands in metal complexes2 and catalysts.

The N-O moiety of pyridine N-oxides possesses a unique functionality of acting effectively as a push electron donor and as a pull electron acceptor group. This strong push-pull property has an essential chemical consequence; it accounts for the equally easy synthesis of 4-substituted derivatives of pyridine N-oxides with donor as well as acceptor groups.

Substituted Halopyridines

Substituted pyridines are important substructures in a multitude of products of the chemical and pharmaceutical industry. Particularly halopyridines are the attractive intermediates for many active ingredients from the class that can readily be converted further. It is likewise readily possible to remove halogen atoms by hydrogenolytic means, particularly in the 2 and 4 posit ion, such that the corresponding parent compounds are usually available very efficiently from the halo pyridines.