Reaktion #56032

Reaktionsgleichung

5-cyano-2-hydroxy-6-methyl-3-pyridine-carboxylic acid, ethyl ester

phosphorous oxychloride

→

2-Chloro-5-cyano-6-methyl-3-pyridine-carboxylic acid, ethyl ester

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe excess of phosphorous oxychloride is removed in vacuo
2. 2
   workup.ADDITIONthe residue poured in 1 kg of ice
3. 3
   Sonstige2-chloro-5-cyano-6-methyl-3-pyridine-carboxylic acid, ethyl ester crystallizes
4. 4
   Filtrationis filtered off

Vorschrift

200 g of 5-cyano-2-hydroxy-6-methyl-3-pyridine-carboxylic acid, ethyl ester (1 mol) are refluxed with stirring in 750 ml of phosphorous oxychloride for 5 hours. The excess of phosphorous oxychloride is removed in vacuo and the residue poured in 1 kg of ice. 2-chloro-5-cyano-6-methyl-3-pyridine-carboxylic acid, ethyl ester crystallizes and is filtered off. Yield 170 g (76%); m.p. 43°-45° C. (petrol ether).

Quelle