反应详情

温度

100 °C

Anhydrous pyridine hydrochloride is prepared by distillation to a temperature of 220° C. from a mixture of 42 g of pyridine and 50 ml of concentrated hydrochloric acid. Under a nitrogen atmosphere, the pyridine hydrochloride is allowed to cool to 100° C. and 5 g of 2-chloro-3-(2-methoxyphenoxy)pyridine is added and the mixture is refluxed 1 hour. The mixture is cooled and 200 ml of water is added. The mixture is extracted with 250 ml diethyl ether and the extracts are washed with 10 ml of concentrated ammonium hydroxide. The ether layer is dried and evaporated to yield the pyrido[2,3-B][1,4]benzodioxin, mp 95°-97° C., after sublimation at 0.1 mm pressure.

1. temperaturethe mixture is refluxed 1 hour
2. temperatureThe mixture is cooled
3. extractionThe mixture is extracted with 250 ml diethyl ether
4. washthe extracts are washed with 10 ml of concentrated ammonium hydroxide
5. dry with materialThe ether layer is dried
6. customevaporated