反応 #2442579

反応方程式

NH4Cl

Chlorotrimethylsilane

7-bromobenzofuran

diisopropylamine

n-BuLi

→

7-bromo-2-(trimethylsilyl)benzofuran

収率 98.0%

溶媒

THF

HCl

THF

反応条件

後処理

1. 1
   温度cooled to −70° C
2. 2
   workup.STIRRINGThe mixture was stirred at −70° C. for 1.5 h
3. 3
   抽出extracted with ether (2×80 mL)
4. 4
   洗浄The combined ether extracts were washed with sat'd aq NaHCO3 (50 mL)
5. 5
   乾燥dried over MgSO4
6. 6
   濃縮concentrated

実験手順

A stirred solution of diisopropylamine (0.65 mL, 4.7 mmol) in THF (15 L) was cooled to 5° C. and n-BuLi (2.5 M in hexanes, 1.9 mL, 4.7 mmol) was added dropwise over 5 min. The mixture was stirred at 5° C. for 15 min and cooled to −70° C. Chlorotrimethylsilane (0.59 mL, 4.7 mmol) was added followed by a solution of 7-bromobenzofuran (0.46 g, 2.35 mmol) in THF (5 mL). The mixture was stirred at −70° C. for 1.5 h and poured into sat'd aq NH4Cl (80 mL). The mixture was diluted with 5% aq HCl (20 mL) and extracted with ether (2×80 mL). The combined ether extracts were washed with sat'd aq NaHCO3 (50 mL), dried over MgSO4 and concentrated to leave crude 7-bromo-2-(trimethylsilyl)benzofuran (0.62 g, 98%) as a yellow oil.

出典