反应详情

温度

70 °C

To a suspension of methyl 5-iodo-1H-indole-3-carboxylate (1.20 g, 3.09 mmol) in acetic acid (30 ml) was added a solution of bromine (0.15 ml, 2.9 mmol) in acetic acid (5 ml). Reaction was heated to reflux and stirred for 3 hours. The reaction was then cooled and poured onto ice water, then partitioned between water and dichloromethane. The aqueous layer was extracted with 10% MeOH/DCM (2×100 mL). The organics were combined, washed with brine, and dried over sodium sulfate, filtered and concentrated to give a dark red semi solid. The residue was taken up in methanol (30 ml). Concentrated sulfuric acid (0.5 ml) was added and mixture was heated to 70° C. for 2 days. The reaction was cooled then concentrated in vacuo and the residue partitioned between ethyl acetate and aqueous sodium bicarbonate solution. The layers were separated and organic washed with brine, dried over sodium sulfate, filtered and concentrated to give a reddish solid. The residue was dissolved in methanol/dichloromethane and adsorbed onto silica gel and purified by silica gel chromatography (50 g, 20-100% ethyl acetate/heptane). The major peak was isolated to afford a mixture of the title compound and methyl 5-iodo-1H-indole-3-carboxylate confirmed as a brown solid (260 mg) that was taken forward without further purification.

1. customReaction
2. temperaturewas heated
3. temperatureto reflux
4. temperatureThe reaction was then cooled
5. additionpoured onto ice water
6. custompartitioned between water and dichloromethane
7. extractionThe aqueous layer was extracted with 10% MeOH/DCM (2×100 mL)
8. washwashed with brine
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated
12. customto give a dark red semi solid
13. temperatureThe reaction was cooled
14. concentrationthen concentrated in vacuo
15. customthe residue partitioned between ethyl acetate and aqueous sodium bicarbonate solution
16. customThe layers were separated
17. washorganic washed with brine
18. dry with materialdried over sodium sulfate
19. filtrationfiltered
20. concentrationconcentrated
21. customto give a reddish solid
22. custompurified by silica gel chromatography (50 g, 20-100% ethyl acetate/heptane)
23. customThe major peak was isolated
24. customto afford