反应详情

To a stirred suspension of 14.8 g of 2,5-dichloropyridine in 50 ml of methanol was added 30 ml of a 25% solution of sodium methoxide in methanol and the mixture was heated to reflux under nitrogen. After 24 hours, another 30 ml of the sodium methoxide solution was added and reflux was continued for a total of 68 hours. The sodium chloride which precipitated was removed by filtration and the filtrate was concentrated at atmospheric pressure to about 1/4 the original volume and partitioned between ether and water. The aqueous layer was extracted with ether and the combined ether layers were washed with saturated sodium chloride solution, dried over potassium carbonate and concentrated at atmospheric pressure to a pale brown oil. This residue was distilled to give 5-chloro-2-methoxypyridine as a colorless liquid boiling at about 82°-84° C. at 20 torr.

1. temperaturethe mixture was heated
2. temperatureto reflux under nitrogen
3. temperaturereflux
4. customwas continued for a total of 68 hours
5. customThe sodium chloride which precipitated
6. customwas removed by filtration
7. concentrationthe filtrate was concentrated at atmospheric pressure to about 1/4 the original volume
8. custompartitioned between ether and water
9. extractionThe aqueous layer was extracted with ether
10. washthe combined ether layers were washed with saturated sodium chloride solution
11. dry with materialdried over potassium carbonate
12. concentrationconcentrated at atmospheric pressure to a pale brown oil
13. distillationThis residue was distilled