反应详情

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°.

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