반응 #43602

반응 방정식

1,2-dibromoethane

3-bromo-4,5-dihydroxybenzaldehyde

cesium carbonate

→

desired compound

수율 75.0%

8-Bromo-2,3-dihydro-1,4-benzodioxin-6-carbaldehyde

수율 75.0%

용매

dimethylformamide

반응 조건

후처리

1. 1
   온도After heating at 80° for 4 h
2. 2
   기타the dimethylformamide was removed under reduced pressure
3. 3
   기타The residue was partitioned between water and ethyl acetate
4. 4
   세척the organic layer was washed with brine
5. 5
   기타dried
6. 6
   기타The crude product was purified by flash column chromatography (silica gel, 4:1 hexane:ethyl acetate)

실험 절차

To a solution of 3-bromo-4,5-dihydroxybenzaldehyde (11.5 g, 0.52 mol) in dimethylformamide (220 ml) was added cesium carbonate (50.7 g, 1.56 mol). The mixture was stirred at ambient temperature for 30 min, then 1,2-dibromoethane (12.76 g, 0.68 mol) were added. After heating at 80° for 4 h, the dimethylformamide was removed under reduced pressure. The residue was partitioned between water and ethyl acetate, and the organic layer was washed with brine and dried. The crude product was purified by flash column chromatography (silica gel, 4:1 hexane:ethyl acetate) to give the desired compound as an off-white solid (9.57 g, 75%).

출처