反应详情

温度

140 °C

4.3 g (30 mmol) of 4-chloro-2-picoline-N-oxide are added to a mixture of 4.6 g (35 mmol) of 2,4-difluorophenol in 25 ml of N,N-dimethylacetamide and 4.9 g (35 mmol) of finely powdered potassium carbonate and the mixture is warmed to 140° C. for 3 hours with stirring. After cooling, the reaction mixture is poured into 250 ml of water, extracted three times using dichloromethane, and the organic phases are dried over MgSO4 and concentrated. The residue is taken up in dichloromethane and extracted by shaking with saturated aqueous NaCl solution. After drying and freeing from solvent, the extract is brought to crystallization using diisopropyl ether and washed with ethyl acetate. Colorless crystals, m.p. 112°-124° C.

1. temperatureAfter cooling
2. extractionextracted three times
3. dry with materialthe organic phases are dried over MgSO4
4. concentrationconcentrated
5. extractionextracted
6. stirringby shaking with saturated aqueous NaCl solution
7. customAfter drying
8. customthe extract is brought to crystallization
9. washwashed with ethyl acetate