Phosphorus pentachloride → 2-Chloro-5,6-dimethylpyridine-3-carbonitrile

Reaction equation

[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]=1

Participants

Reactant 2

HCID 24819Phosphorus pentachloride

HCID 178426619HCID 178426619, compound

Product 1

HCID 128911062-Chloro-5,6-dimethylpyridine-3-carbonitrileYield 53.6%

Procedure

An intimate mixture of 3-cyano-5,6-dimethyl-2-hydroxypyridine (42 g) and phosphorous pentachloride (81 g) was heated at 140°-160° for 2 hours. Phosphoryl chloride was removed by distillation under reduced pressure and ice-water (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-light petroleum (b.p. 60°-80°) to give 2-chloro-3-cyano-5,6-dimethylpyridine (25.3 g), m.p. 83°-7°.

Workup

temperaturewas heated at 140°-160° for 2 hours
customPhosphoryl chloride was removed by distillation under reduced pressure and ice-water (500 g)
additionwas added to the residue
extractionextracted with ether
customThe ether extracts were evaporated to an oil which
customwas crystallised from ether-light petroleum (b.p. 60°-80°)

Sources & evidence

ORD record: ord-bb959b720fe04a9e808bc563241e47e4
Source dataset: uspto-grants-1980_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04227000

Reaction notes

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