反应详情

To a stirred mixture of 2.0 g (6.5 mmol) of 4,5-dichloro-2-(3,4-dichlorophenyl)-pyrrole-3-carbonitrile and 0.88 g (7.8 mmol) of potassium tert-butoxide heated at reflux in 50 mL of dioxane is added 0.98 g (7.8 mmol) of bromoethanol. The mixture is stirred at reflux for 12 hours, cooled, diluted with 50 mL of water, and extracted several times with chloroform. The combined chloroform extracts are dried over magnesium sulfate and concentrated in vacuo to leave a solid which, on warming and dissolving in ethyl acetate, deposits on cooling mostly starting pyrrole. Concentration of the mother liquor and recrystallization of the residual solid from 20% ethyl acetate in hexane gives 0.31 g of a white solid, mp 143°-145° C.; IR 5077A.

1. temperatureheated
2. temperatureat reflux for 12 hours
3. temperaturecooled
4. extractionextracted several times with chloroform
5. dry with materialThe combined chloroform extracts are dried over magnesium sulfate
6. concentrationconcentrated in vacuo
7. customto leave a solid which
8. temperatureon warming
9. customConcentration of the mother liquor and recrystallization of the residual solid from 20% ethyl acetate in hexane