反応 #1894551

反応方程式

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

1,2-difluoro-3-methylbenzene

n-butyllithium

diisopropylamine

→

title compound

収率 50.5%

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

収率 50.5%

溶媒

THF

THF

ether

THF

反応条件

後処理

1. 1
   温度cooled to −78° C
2. 2
   workup.STIRRINGstirred at −78° C. for 2 h
3. 3
   温度the brown solution was slowly warmed to 23° C. over 16 hours
4. 4
   抽出extracted with water and with 0.1N sodium hydroxide
5. 5
   抽出then extracted with dichloromethane
6. 6
   その他The organic phase was dried
7. 7
   濃縮concentrated

実験手順

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).

出典