Reaktion #4890

Reaktionsgleichung

5-bromo-2-hydroxy nicotinic acid

thionyl chloride

→

5-Bromo-2-chloro-3-pyridinecarboxylic acid

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was heated
2. 2
   Temperaturto reflux for 30 minutes
3. 3
   TemperaturAfter cooling
4. 4
   Sonstigethe excess thionyl chloride was removed by rotary evaporation
5. 5
   workup.ADDITIONthe residue poured into water (1 liter) with vigorous agitation
6. 6
   SonstigeThe precipitate was collected
7. 7
   Sonstigethe mother liquor condensed to 1/2 the volume
8. 8
   Sonstigeyielding additional precipitate
9. 9
   Sonstigecrystallized from toluene giving 6 g (37%) of material
10. 10
    SonstigeThe product was recrystallized from toluene, m.p. 174°-177° C.

Vorschrift

To 15 g (0.069 mole) of 5-bromo-2-hydroxy nicotinic acid was added 75 ml of thionyl chloride and 3 ml of dimethylformamide. The mixture was heated to reflux for 30 minutes. After cooling, the excess thionyl chloride was removed by rotary evaporation and the residue poured into water (1 liter) with vigorous agitation. The precipitate was collected and the mother liquor condensed to 1/2 the volume, yielding additional precipitate. The precipitates were combined and crystallized from toluene giving 6 g (37%) of material. The product was recrystallized from toluene, m.p. 174°-177° C.

Quelle