Reaktion #736391

Reaktionsgleichung

3-Methoxy-2-methyl-4(1H)-pyridone

phosphorus oxychloride

→

4-chloro-3-methoxy-2-methylpyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturrefluxed for 10 hours
2. 2
   Einengenconcentrated
3. 3
   workup.ADDITIONTo the resultant residue was added toluene
4. 4
   Sonstigethe residual phosphorus oxychloride was evaporated under reduced pressure
5. 5
   workup.ADDITIONTo the resultant oily substance were added chloroform and water
6. 6
   Sonstigethe chloroform layer was separated
7. 7
   Extraktionextracted with chloroform
8. 8
   SonstigeThe chloroform solutions thus obtained
9. 9
   Waschenwashed with water
10. 10
    Sonstigedried
11. 11
    Sonstigeevaporated
12. 12
    SonstigeThe residue was purified by column chromatography on silica gel

Vorschrift

3-Methoxy-2-methyl-4(1H)-pyridone (5.6 g) was suspended in phosphorus oxychloride (50 ml), refluxed for 10 hours, and concentrated. To the resultant residue was added toluene and the residual phosphorus oxychloride was evaporated under reduced pressure. To the resultant oily substance were added chloroform and water and the chloroform layer was separated. The aqueous layer was made alkaline with potassium carbonate and extracted with chloroform. The chloroform solutions thus obtained were combined, washed with water, dried, and evaporated. The residue was purified by column chromatography on silica gel, to give 4-chloro-3-methoxy-2-methylpyridine (4.8 g) as a light brown oil.

Quelle