Реакция #2075721

Уравнение реакции

1-chloro-3-fluoro-2-(1-fluoroethyl)benzene

n-butyllithium

diisopropylamine

2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

→

title compound

Выход 94.0%

2-(4-Chloro-2-fluoro-3-(1-fluoroethyl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Выход 94.0%

Растворители

THF

hydrochloric acid

tetrahydrofuran THF

Условия реакции

Обработка

1. 1
   Температураwarmed to 0° C. for 20 m
2. 2
   Температураcooled back to −78° C. for 20 m
3. 3
   Другоеat −78° C.
4. 4
   workup.STIRRINGThe resulting dark brown solution was stirred at −78° C. for 2 h
5. 5
   Температураthe brown solution was slowly warmed to 23° C. over 20 h
6. 6
   Экстракцияextracted with dichloromethane three times
7. 7
   ДругоеThe combined organic layers were dried
8. 8
   Фильтрацияfiltered
9. 9
   Концентрированиеconcentrated by rotary evaporation

Методика

A 2.5 M solution of n-butyllithium (13 mL, 33 mmol) was added to a stirred solution of diisopropylamine (5.0 mL, 35 mmol) in tetrahydrofuran THF (50 mL) at −78° C. The resulting colorless solution was stirred at −78° C. for 20 m, warmed to 0° C. for 20 m, and then cooled back to −78° C. for 20 m. A solution of 1-chloro-3-fluoro-2-(1-fluoroethyl)benzene (4.8 g, 27 mmol, 1.0 equiv) in THF (20 mL) at −78° C. was transferred to the base solution via cannula. The resulting dark brown solution was stirred at −78° C. for 2 h. 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (8.3 mL, 41 mmol, 1.5 equiv) was added and the brown solution was slowly warmed to 23° C. over 20 h. The reaction mixture was diluted with 0.1M hydrochloric acid (300 mL) and extracted with dichloromethane three times. The combined organic layers were dried, filtered and concentrated by rotary evaporation to afford the title compound as a brown oil that solidified into a semi-solid upon standing (7.7 g, 94% yield). 1H NMR (300 MHz, CDCl3) δ 7.62 (m, 1H), 7.17 (m, 1H), 6.13 (dq, 1H, J=6, 46 Hz), 1.75 (ddd, 3H, J=1, 7, 23 Hz), 1.36 (s, 12 H).

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