反応 #657251

反応方程式

ammonium chloride

n-butyllithium

19

5,7-Dibromo-2,3-dihydrobenzofuran

N,N-dimethylformamide

→

crystals

収率 27.1%

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

収率 27.1%

溶媒

THF

反応条件

後処理

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

実験手順

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.

出典