反应详情

A solution of bromine (0.62 ml) in dioxane (25 ml) is added dropwise over a period of 2 hours to a mixture of 5-methoxy-3-methylindole (2.00 g) and imidazole (4.08 g) in dioxane (50 ml) while stirring at 10°. Upon complete addition cooling bath is removed and the suspension is stirred two days at room temperature. The mixture is concentrated in vacuo and the oil obtained is suspended in ether (100 ml) and extracted into 1N hydrochloric acid (2×50 ml). The acid extract is first washed with ether (1×50 ml), the pH is adjusted to pH 6 with 3N sodium hydroxide (38 ml), and the aqueous mixture is then extracted with ether (8×50 ml). This extract is dried over magnesium sulfate, filtered, and concentrated in vacuo to give an oil. This oil is purified by flash chromatography on silica gel (eluent: 95% methylene chloride, 5% methanol) to give 2-(1-imidazolyl)-5-methoxy-3-methylindole as a crystalline solid; NMR (CDCl3): δ10.4 (s, 1H), 7.67 (s, 1H), 3.88 (s, 3H), 2.22 (s, 3H).

1. additionUpon complete addition
2. temperaturecooling bath
3. customis removed
4. stirringthe suspension is stirred two days at room temperature
5. concentrationThe mixture is concentrated in vacuo
6. customthe oil obtained
7. extractionextracted into 1N hydrochloric acid (2×50 ml)
8. extractionThe acid extract
9. washis first washed with ether (1×50 ml)
10. extractionthe aqueous mixture is then extracted with ether (8×50 ml)
11. dry with materialThis extract is dried over magnesium sulfate
12. filtrationfiltered
13. concentrationconcentrated in vacuo
14. customto give an oil
15. customThis oil is purified by flash chromatography on silica gel (eluent: 95% methylene chloride, 5% methanol)