反应详情

温度

100 °C

To a solution of 3-bromo-4,5-dihydroxy-benzaldehyde (20.78 g, 95 mmol) in 480 ml DMF was added K2CO3 (52.95 g, 383 mmol) followed by 1,2-dibromoethane (8.7 ml, 101 mmol). The mixture was warmed to 100° C. After 18 additional 1,2 dibromoethane (1.0 mL) was added. After 2 h the mixture was poured into water and extracted with ethyl acetate. The combined organics were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The crude solid was purified via flash chromatography (9:1 hexane/ethyl acetate) to give 8-bromo-2,3-dihydro-benzo[1,4]dioxine-6-carboxaldehyde (115.82 g, 99%) as a white solid.

1. extractionextracted with ethyl acetate
2. washThe combined organics were washed with brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe crude solid was purified via flash chromatography (9:1 hexane/ethyl acetate)