反应详情

温度

-40 °C

To a solution of 3-bromo-5-(prop-1-ynyl)pyridine (2.96 g, 15.10 mmol) and triisopropyl borate (4.21 ml, 18.12 mmol) in THF and toluene at −40° C. was added n-BuLi (2.5 M solution in hexanes, 7.25 mL, 18.12 mmol) drop wise over a period of 7 min, and the reaction mixture was stirred at −40° C. for 30 min and then warmed up to −20° C. over a period of 8 min. The reaction was quenched with HCl (15.10 ml, 2 M solution, 30.2 mmol), and a reddish solution was formed. The two layers were separated, and the organic layer was extracted with water (3×10 mL). To the combined organic layers were added NaOH (5M solution, 2.416 ml, 12.08 mmol) (to adjust pH to 7). During the addition, a very white cloudy solution was formed. THF (30 mL) was added, but the layers did not separate. Solid sodium chloride was added to make the solution saturated, and the two layers were formed. The layers were separated, and the aqueous layer was extracted with THF (3×20 mL), and the combined THF layers were dried over sodium sulfate and then filtered. The filtrate was evaporated in vacuo, and the residue was concentrated to give a white powder (553 mg). This material was used without further purification.

1. temperaturewarmed up to −20° C. over a period of 8 min
2. customa reddish solution was formed
3. customThe two layers were separated
4. extractionthe organic layer was extracted with water (3×10 mL)
5. additionDuring the addition
6. customa very white cloudy solution was formed
7. customthe layers did not separate
8. additionSolid sodium chloride was added
9. customthe two layers were formed
10. customThe layers were separated
11. extractionthe aqueous layer was extracted with THF (3×20 mL)
12. dry with materialthe combined THF layers were dried over sodium sulfate
13. filtrationfiltered
14. customThe filtrate was evaporated in vacuo
15. concentrationthe residue was concentrated