Reacción #1994290

Ecuación de reacción

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

1,2-difluoro-3-methylbenzene

n-butyllithium

diisopropylamine

→

title compound

Rendimiento 50.5%

2-(2,3-Difluoro-4-methylphenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane

Rendimiento 50.5%

Disolventes

THF

THF

ether

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturacooled to −78° C
2. 2
   workup.STIRRINGstirred at −78° C. for 2 h
3. 3
   Temperaturathe brown solution was slowly warmed to 23° C. over 16 hours
4. 4
   Extracciónextracted with water and with 0.1N sodium hydroxide
5. 5
   Extracciónthen extracted with dichloromethane
6. 6
   OtroThe organic phase was dried
7. 7
   Concentraciónconcentrated

Procedimiento

A 2.5 M solution of n-butyllithium (3.4 mL, 8.5 mmol) was added to a stirred solution of diisopropylamine (1.2 mL, 8.5 mmol) in THF (25 mL) at −20° C. The resulting solution was stirred at −20° C. for 10 minutes, then cooled to −78° C. A solution of 1,2-difluoro-3-methylbenzene (1.0 g, 7.8 mmol) in THF was added dropwise and stirred at −78° C. for 2 h. 2-Isopropoxy-4,4,5,5-tetramethyl[1,3,2]dioxaborolane (1.6 g, 8.6 mmol) in THF was then added and the brown solution was slowly warmed to 23° C. over 16 hours. The reaction mixture was then added to ether and extracted with water and with 0.1N sodium hydroxide. The combined aqueous extracts were acidified with concentrated HCl then extracted with dichloromethane. The organic phase was dried and concentrated to give the title compound (1.0 g, 50% yield): 1H NMR (CDCl3): δ 7.32 (m, 1H), 6.92 (m, 1H), 2.31 (s, 3H), 1.32 (s, 12H).

Fuente