The reactivity of halogen atoms occupying positions 3 and 5 in 2,4‐dihydroxypyridine: A new synthesis of 5‐chloro‐2,4‐dihydroxypyridine
- 1 January 1954
- journal article
- research article
- Published by Wiley in Recueil des Travaux Chimiques des Pays-Bas
- Vol. 73 (9) , 704-708
- https://doi.org/10.1002/recl.19540730902
Abstract
A survey is given of the rearrangements occurring during the heating of the monobromo and monochloro derivatives of 2,4‐dihydroxypyridine, substituted at positions 3 or 5, with hydrobromic and hydrochloric acid.In this connection the reactivity of 3,5‐dibromo‐ and 3,5‐dichloro‐2,4‐dihydroxypyridine has been investigated. It has been found that the halogen atoms at position 3 are replaced by hydrogen in both compounds when they are heated with an aqueous solution of hydrobromic acid to which sodium bisulphite, aniline or another halogen bonding substance is added. When, on the contrary, the dihalogeno derivatives are treated with hydrogen in the presence of a palladium catalyst, the halogen atoms occupying the 5 position are replaced by hydrogen.These results open up an easy route for the synthesis of 5‐chloro‐2,4‐dihydroxypyridine from 2,4‐dihydroxypyridine as a starting substance.Keywords
This publication has 5 references indexed in Scilit:
- Synthesis and reactivity of 5-chloro-2,4-dihydroxypyridineRecueil des Travaux Chimiques des Pays-Bas, 1953
- Influence of the solvent on the reactivity of halogeno‐ and alkoxy‐derivatives of nitropyridines towards ammoniaRecueil des Travaux Chimiques des Pays-Bas, 1953
- Migration of halogen atoms in halogenoderivatives of 2,4‐dihydroxypyridine (I)Recueil des Travaux Chimiques des Pays-Bas, 1951
- The chloropyridinesRecueil des Travaux Chimiques des Pays-Bas, 1950
- On bromopyridines: (59th communication on derivatives of pyridine and quinoline)Recueil des Travaux Chimiques des Pays-Bas, 1945