반응 #62880

반응 방정식

4-fluorobenzaldehyde

aluminium trichloride

Bromine

→

3-bromo-4-fluorobenzaldehyde

수율 56.3%

용매

dichloromethane

dichloromethane

반응 조건

후처리

1. 1
   온도a cooled
2. 2
   온도the mixture heated at the reflux temperature of 16 hours
3. 3
   온도After cooling
4. 4
   workup.ADDITIONthe reaction mixture was carefully poured onto ice
5. 5
   추출extracted with dichloromethane
6. 6
   세척The combined organic layers were washed with saturated sodium metabisulphite solution, water and brine
7. 7
   건조dried over anhydrous magnesium sulphate
8. 8
   기타Evaporation of the solvent under reduced pressure
9. 9
   기타gave a dark red oil, which
10. 10
    workup.DISTILLATIONwas purified by distillation under reduced pressure

실험 절차

A solution of 4-fluorobenzaldehyde (49.6 g) in dry dichloromethane (20 cm3) was added to a cooled (0° C.) suspension of powdered aluminium trichloride (90.4 g) in dry dichloromethane (100 cm3). Bromine (70.4 g) was added, and the mixture heated at the reflux temperature of 16 hours. After cooling, the reaction mixture was carefully poured onto ice and extracted with dichloromethane. The combined organic layers were washed with saturated sodium metabisulphite solution, water and brine, then dried over anhydrous magnesium sulphate. Evaporation of the solvent under reduced pressure gave a dark red oil, which was purified by distillation under reduced pressure, using a 4" Vigreux column to give 3-bromo-4-fluorobenzaldehyde (45.7 g) as an oil, boiling point 85°-108° C. at 8 mmHg.

출처