Reacción #736391

Ecuación de reacción

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

phosphorus oxychloride

→

4-chloro-3-methoxy-2-methylpyridine

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturarefluxed for 10 hours
2. 2
   Concentraciónconcentrated
3. 3
   workup.ADDITIONTo the resultant residue was added toluene
4. 4
   Otrothe residual phosphorus oxychloride was evaporated under reduced pressure
5. 5
   workup.ADDITIONTo the resultant oily substance were added chloroform and water
6. 6
   Otrothe chloroform layer was separated
7. 7
   Extracciónextracted with chloroform
8. 8
   OtroThe chloroform solutions thus obtained
9. 9
   Lavadowashed with water
10. 10
    Otrodried
11. 11
    Otroevaporated
12. 12
    OtroThe residue was purified by column chromatography on silica gel

Procedimiento

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.

Fuente