反应详情

To a stirring solution of 2-bromo 5-methylsulfanyl pyridine (3.05 g 14.9 mmol), triethylamine (2.10 mL, 14.9 mmol) and (1-ethoxyvinyl)tributyl tin (10.1 mL, 29.8 mmol) in anhydrous 1,4-dioxane (100 mL), was added dichlorobis(triphenylphosphine) palladium (II) (5 mol %, 0.524 g) and the reaction heated to reflux under nitrogen for 18 hours. After cooling, dichlorobis(triphenylphosphine) palladium (II) was added and the reaction heated under nitrogen for a further 18 hours. The reaction was allowed to cool and-the reaction mixture partitioned between saturated aqueous potassium fluoride solution (250 mL) and diethyl ether (250 mL). The ether layer was separated and 2N hydrochloric acid (250 mL) added. The acid layer was separated and sodium carbonate added portionwise until the solution reached pH 8. The solution was extracted with dichloromethane (3×200 mL). The organic extracts were combined and the solvent removed. The residue was partitioned between cyclohexane (60 ml) and acetonitrile (60 mL). The acetonitrile layer was separated and the solvent removed to yield a brown solid. The crude product was purified by flash column chromatography (cyclohexane:ethyl acetate, 95:5) to afford the title compound as a white solid:

1. temperaturethe reaction heated
2. temperatureto reflux under nitrogen for 18 hours
3. temperatureAfter cooling
4. temperaturethe reaction heated under nitrogen for a further 18 hours
5. temperatureto cool
6. custom-the reaction mixture partitioned between saturated aqueous potassium fluoride solution (250 mL) and diethyl ether (250 mL)
7. customThe ether layer was separated
8. addition2N hydrochloric acid (250 mL) added
9. customThe acid layer was separated
10. additionsodium carbonate added portionwise until the solution
11. extractionThe solution was extracted with dichloromethane (3×200 mL)
12. customthe solvent removed
13. customThe residue was partitioned between cyclohexane (60 ml) and acetonitrile (60 mL)
14. customThe acetonitrile layer was separated
15. customthe solvent removed
16. customto yield a brown solid
17. customThe crude product was purified by flash column chromatography (cyclohexane:ethyl acetate, 95:5)