Phosphorus pentachloride → 2-Chloro-5,6-dimethylpyridine-3-carbonitrile
Reaktionsgleichung
[C:1]([C:3]1[C:4](O)=[N:5][C:6]([CH3:10])=[C:7]([CH3:9])[CH:8]=1)#[N:2].P(Cl)(Cl)(Cl)(Cl)[Cl:13]>>[Cl:13][C:4]1[C:3]([C:1]#[N:2])=[CH:8][C:7]([CH3:9])=[C:6]([CH3:10])[N:5]=1Komponenten
3
Versuchsvorschrift
An intimate mixture of 3-cyano-5,6-dimethyl-2-hydroxypyridine (42 g) and phosphorus pentachloride (81 g) was heated at 140°-160° for 2 hours. Phosphoryl chloride was removed by distillation under reduced pressure and icewater (500 g) was added to the residue. The mixture was adjusted to pH 7 with aqueous sodium hydroxide and extracted with ether. The ether extracts were evaporated to an oil which was crystallised from ether/petroleum ether (b.p. 60°-80°) to give 2-chloro-3-cyano-5,6-dimethylpyridine (25.3 g) m.p. 83°-87°.
Aufarbeitung
- temperaturewas heated at 140°-160° for 2 hours
- customPhosphoryl chloride was removed by distillation under reduced pressure and icewater (500 g)