反应详情

A stirred mixture of 3,5-dibromo-4-hydroxyacetophenone (3.0 g, 10.1 mmol), K2CO3 (2.8 g, 20.3 mmol), 1,3-dibromo- propane (4.0 g, 19.8 mmol) in acetonitrile (100 ml) was heated at reflux for 5 hours. The solvent was removed. The crude product was extracted into dichloromethane (150 ml) and the insoluble inorganics were filtered off. The solution was concentrated to dryness again. Purification was carried out by flash chromatography on silica gel (45 g, SiO2 ; eluted with 1:1 hexane:dichloromethane). The material thus obtained (2.8 g) was recrystallized twice from isopropyl ether to give analytically pure 1-[4-(3-bromopropoxy)-3,5-dibromophenyl]ethanone, m.p.=87°-88° C.

1. temperaturewas heated
2. temperatureat reflux for 5 hours
3. customThe solvent was removed
4. extractionThe crude product was extracted into dichloromethane (150 ml)
5. filtrationthe insoluble inorganics were filtered off
6. concentrationThe solution was concentrated to dryness again
7. customPurification
8. customThe material thus obtained (2.8 g)
9. customwas recrystallized twice from isopropyl ether