反応 #43602

反応方程式

1,2-dibromoethane

3-bromo-4,5-dihydroxybenzaldehyde

cesium carbonate

→

desired compound

収率 75.0%

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

収率 75.0%

溶媒

dimethylformamide

反応条件

後処理

1. 1
   温度After heating at 80° for 4 h
2. 2
   その他the dimethylformamide was removed under reduced pressure
3. 3
   その他The residue was partitioned between water and ethyl acetate
4. 4
   洗浄the organic layer was washed with brine
5. 5
   その他dried
6. 6
   その他The crude product was purified by flash column chromatography (silica gel, 4:1 hexane:ethyl acetate)

実験手順

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%).

出典