|
Chloropyridine
Chloropyridines are a group of aryl chlorides consisting of a pyridine ring with chlorine atoms as substituents. This may refer to: * 2-Chloropyridine *3-Chloropyridine * 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: : 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 gives pyridylmercaptoacetic acid, a step in the production of cephalosporin The cephalosporins (sg. ) are a class of β-lactam antibiotics originally derived from the fungus ''Acremonium'', which was previously known as ''Cephalosporium''. Together with cephamycins, they constitute a subgroup of β-l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrithione
Pyrithione is the common name of an organosulfur compound with molecular formula , chosen as an abbreviation of pyridinethione, and found in the Persian shallot. It exists as a pair of tautomers, the major form being the thione 1-hydroxy-2(1''H'')-pyridinethione and the minor form being the thiol 2-mercaptopyridine ''N''-oxide; it crystallises in the thione form. It is usually prepared from either 2-bromopyridine, 2-chloropyridine, or 2-chloropyridine ''N''-oxide, and is commercially available as both the neutral compound and its sodium salt. It is used to prepare zinc pyrithione, which is used primarily to treat dandruff and seborrhoeic dermatitis in medicated shampoos, though is also an anti-fouling agent in paints. Preparation The preparation of pyrithione was first reported in 1950 by Shaw and was prepared by reaction of 2-chloropyridine ''N''-oxide with sodium hydrosulfide followed by acidification, or more recently with sodium sulfide. 2-chloropyridine ''N''-oxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,6-Dichloropyridine
2,6-Dichloropyridine is a chloropyridine with the formula C5H3Cl2N. A white solid, it is one of six isomers of dichloropyridine. It serves as a precursor to the antibiotic enoxacin, as well as the drug and anpirtoline and the antifungal liranaftate. Synthesis 2,6-Dichoropyridine is produced by reaction of pyridine with chlorine. 2-Chloropyridine is an intermediate. Toxicity The is 115 mg/kg (oral, mice). References Chloropyridines {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
