反応 #2075721

反応方程式

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

n-butyllithium

diisopropylamine

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

→

title compound

収率 94.0%

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

収率 94.0%

溶媒

THF

hydrochloric acid

tetrahydrofuran THF

反応条件

後処理

1. 1
   温度warmed to 0° C. for 20 m
2. 2
   温度cooled back to −78° C. for 20 m
3. 3
   その他at −78° C.
4. 4
   workup.STIRRINGThe resulting dark brown solution was stirred at −78° C. for 2 h
5. 5
   温度the brown solution was slowly warmed to 23° C. over 20 h
6. 6
   抽出extracted with dichloromethane three times
7. 7
   その他The combined organic layers were dried
8. 8
   ろ過filtered
9. 9
   濃縮concentrated by rotary evaporation

実験手順

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).

出典