Chloropyridines are a group of aryl chlorides consisting of a

pyridine Pyridine is a basic heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom. It is a highly flammable, weakly alkaline, water-miscible liquid with a ...

ring with

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

atoms as substituents. This may refer to: * 2-Chloropyridine *

3-Chloropyridine 3-Chloropyridine is an organohalide with the formula C5H4ClN. It is a colorless liquid that is mainly used as a building block in organic synthesis. The compound is a substrate for many coupling processes including the Heck reaction, Suzuki reac ...

* 4-Chloropyridine * 2,6-Dichloropyridine

Production

Direct halogenation of pyridine with chlorine gas above 270 °C gives a mixture of 2-chloropyridine and 2,6-dichloropyridine. 2- and 4-chloropyridine are prepared from the corresponding pyridinols using

phosphoryl chloride Phosphoryl chloride (commonly called phosphorus oxychloride) is a colourless liquid with the formula . It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from phos ...

: :

Uses

Chloropyridines are important intermediates to pharmaceuticals and agrochemicals. A major use of 2-chloropyridine is the production of production of the fungicide pyrithione. Reaction of 4-chloropyridine with

thioglycolic acid Thioglycolic acid (TGA) is the organic compound HSCH2CO2H. TGA is often called mercaptoacetic acid (MAA). It contains both a thiol ( mercaptan) and carboxylic acid functional groups. It is a colorless liquid with a strongly unpleasant odor. TGA i ...

gives pyridylmercaptoacetic acid, a step in the production of cephalosporin antibiotics.

References

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Production

Uses

See also

References