反应 #657251

反应方程式

ammonium chloride

n-butyllithium

19

5,7-Dibromo-2,3-dihydrobenzofuran

N,N-dimethylformamide

→

crystals

收率 27.1%

5-Bromo-2,3-dihydrobenzofuran-7-carbaldehyde

收率 27.1%

溶剂

THF

反应条件

后处理

1. 1
   其他was degassed at −78° C.
2. 2
   其他The solvent was removed
3. 3
   洗涤washed with water (3×50 mL)
4. 4
   干燥then dried with anhydrous sodium sulfate
5. 5
   其他Solvent removal

实验过程

A sample of 19 (6.0 g, 26.5 mmol) in freshly distilled dry THF was degassed at −78° C. and n-butyllithium (25 mL of 1.05 M, 26 mmol) was added dropwise by syringe. Then N,N-dimethylformamide (2.9 mL, 26 mmol) was added dropwise via syringe. The reaction mixture was allowed to come to room temperature overnight. Saturated ammonium chloride (10 mL) was added to and the mixture was stirred for 30 minutes. The solvent was removed and the residue was taken up in dichloromethane (50 mL), and washed with water (3×50 mL) then dried with anhydrous sodium sulfate. Solvent removal yielded yellow crystals (1.6 g) which were washed with ether and recrystallized from a minimum of hot methanol to give white crystals of 20 (1.32 g, 22%) mp=99-100° C.

来源