Reacción #48107

Ecuación de reacción

hydrochloric acid

triisopropyl borate

1-bromo-4-cyclopropyl-benzene

→

product

4-Cyclopropyl-phenylboronic acid

Disolventes

hexane

THF

toluene

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONis added
2. 2
   TemperaturaThe solution is warmed to −20° C.
3. 3
   TemperaturaThe reaction mixture is further warmed to room temperature
4. 4
   Otrothe organic phase is separated
5. 5
   ExtracciónThe aqueous phase is extracted with ethyl acetate
6. 6
   Secadothe combined organic phases are dried (sodium sulphate)
7. 7
   OtroThe solvent is evaporated
8. 8
   Lavadothe residue is washed with a mixture of ether and cyclohexane

Procedimiento

2.5 M nButyllithium in hexane (14.5 mL) is added dropwise to 1-bromo-4-cyclopropyl-benzene (5.92 g) in THF (14 mL) and toluene (50 mL) chilled to −70° C. The resultant solution is stirred at −70° C. for 30 min before triisopropyl borate (8.5 mL) is added. The solution is warmed to −20° C. and then treated with 4 M aqueous hydrochloric acid (15.5 mL). The reaction mixture is further warmed to room temperature and then the organic phase is separated. The aqueous phase is extracted with ethyl acetate and the combined organic phases are dried (sodium sulphate). The solvent is evaporated and the residue is washed with a mixture of ether and cyclohexane to give the product as a colorless solid.

Fuente