Reacción #332457

Ecuación de reacción

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

n-butyllithium

diisopropylamine

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

→

title compound

Rendimiento 94.0%

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

Rendimiento 94.0%

Disolventes

hydrochloric acid

THF

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawarmed to 0° C. for 20 min
2. 2
   workup.STIRRINGThe resulting dark brown solution was stirred at −78° C. for 2 h
3. 3
   Temperaturathe brown solution was slowly warmed to 23° C. over 20 h
4. 4
   Extracciónextracted with dichloromethane thrice
5. 5
   OtroThe combined organic extracts were dried
6. 6
   Filtraciónfiltered
7. 7
   Concentraciónconcentrated by rotary evaporation

Procedimiento

A 2.5M solution of n-butyllithium (13 mL, 33 mmol) was added to a stirred solution of diisopropylamine (5.0 mL, 35 mmol) in THF (50 mL) at −78° C. The resulting colorless solution was stirred at −78° C. for 20 min, warmed to 0° C. for 20 min, and then cooled back to −78° C. for 20 min 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 thrice. The combined organic extracts 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).

Fuente