反应详情

4-Bromo-2-chloro-6-fluoro-phenol (0.500 g, 2.21 mmol) is dissolved in dry THF, the reaction mixture is cooled to −78° C. (dry-ice/acetone bath) and 2.5M n-butylithium (1.06 ml, 2.66 mmol) is slowly added drop wise with stirring for 5 minutes. TMSCl (0.298 ml, 2.33 mmol) is added drop wise maintaining the temperature below −70° C. and the reaction mixture is stirred for 30 minutes. Boric acid triethyl ester is then added (0.385 ml, 2.26 mmol) followed by the second addition of n-butylitlium (1.06 ml, 2.66 mmol) maintaining the temperature below −65° C. The reaction mixture is stirred at −70° C. for 30 minutes then quenched with 5M HCl (5 ml) and allowed to warm to room temperature with stirring for 30 minutes. The reaction mixture is diluted with water and EtOAc and the organic portion is washed with 5M NaOH. The aqueous layer is acidified with 5M HCl and extracted with EtOAc, this organic portion is washed with brine, dried over MgSO4 and concentrated in vacuo to afford the title compound as an off white solid.

1. temperaturewise maintaining the temperature below −70° C.
2. stirringthe reaction mixture is stirred for 30 minutes
3. additionfollowed by the second addition of n-butylitlium (1.06 ml, 2.66 mmol)
4. temperaturemaintaining the temperature below −65° C
5. stirringThe reaction mixture is stirred at −70° C. for 30 minutes
6. customthen quenched with 5M HCl (5 ml)
7. stirringwith stirring for 30 minutes
8. additionThe reaction mixture is diluted with water and EtOAc
9. washthe organic portion is washed with 5M NaOH
10. extractionextracted with EtOAc
11. washthis organic portion is washed with brine
12. dry with materialdried over MgSO4
13. concentrationconcentrated in vacuo