反应详情

A mixture of 45.0 g (0.21 mol) of 2-bromoselenophene, 52.0 g (0.26 mol) of 4-ethoxy-2,3-difluorophenylboronic acid, 20.0 g (17.3 mmol) of tetrakis(triphenylphosphine)palladium(0) and 600 ml of 2 N sodium carbonate soln. in 1100 ml of toluene/ethanol (1:1) is heated under reflux for 20 h. After cooling, the organic phase is separated off, and the aqueous phase is extracted with toluene. The combined organic phases are washed with sat. sodium hydrogencarbonate soln., 1 N hydrochloric acid and sat. sodium chloride soln. The solution is dried using sodium sulfate and concentrated to dryness. The residue is purified by column chromatography (SiO2, n-heptane:toluene=3:2). Further purification is carried out by recrystallisation from ethanol; 2-(4-ethoxy-2,3-difluorophenyl)selenophene is obtained as a beige solid.

1. temperatureunder reflux for 20 h
2. temperatureAfter cooling
3. customthe organic phase is separated off
4. extractionthe aqueous phase is extracted with toluene
5. washThe combined organic phases are washed with sat. sodium hydrogencarbonate soln
6. customThe solution is dried
7. concentrationconcentrated to dryness
8. customThe residue is purified by column chromatography (SiO2, n-heptane:toluene=3:2)
9. customFurther purification
10. customis carried out by recrystallisation from ethanol