Reaction #2075719

Reaction equation

HCl

n-Butyllithium

4-Bromo-1-chloro-2-(1-fluoroethyl)benzene

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

→

title compound

Yield 50.7%

2-[4-Chloro-3-(1-fluoro-ethyl)-phenyl]-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane

Yield 50.7%

Solvents

water

diethyl ether

diethyl ether

Conditions

Workup

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   Otherthe temperature below −70° C
3. 3
   Extractionthe product was then extracted with diethyl ether
4. 4
   OtherThe organic phase was dried
5. 5
   Concentrationconcentrated under vacuum

Procedure

4-Bromo-1-chloro-2-(1-fluoroethyl)benzene (2.55 g, 10.74 mmol) was dissolved in dry diethyl ether (50 mL) and cooled to −75° C. n-Butyllithium (4.72 mL, 11.81 mmol) was added dropwise keeping the temperature below −70° C. The reaction mixture was then stirred for 15 min, then 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.197 g, 11.81 mmol) was added and the reaction mixture was allowed to warm to room temperature. The reaction mixture was then diluted with water and diethyl ether. The aqueous phase was acidified with 12N HCl and the product was then extracted with diethyl ether. The organic phase was dried and concentrated under vacuum to yield the title compound (1.55 g, 5.45 mmol, 50.7% yield) as a white solid: 1H NMR (CDCl3): δ 7.94 (d, 1H), 7.65 (m, 1H), 7.36 (m, 1H), 5.96 (dq, 1H), 1.64 (dd, 3H), 1.34 (s, 12H).

Source