Réaction #1994290

Équation de réaction

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

1,2-difluoro-3-methylbenzene

n-butyllithium

diisopropylamine

→

title compound

Rendement 50.5%

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

Rendement 50.5%

Solvants

THF

THF

ether

THF

Conditions de réaction

Traitement

1. 1
   Températurecooled to −78° C
2. 2
   workup.STIRRINGstirred at −78° C. for 2 h
3. 3
   Températurethe brown solution was slowly warmed to 23° C. over 16 hours
4. 4
   Extractionextracted with water and with 0.1N sodium hydroxide
5. 5
   Extractionthen extracted with dichloromethane
6. 6
   AutreThe organic phase was dried
7. 7
   Concentrationconcentrated

Mode opératoire

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).

Source