反応 #302856

反応方程式

boron tribromide

compound 19

6-iodo-4′-methoxyflavone

→

compound 20

6-bromo-4′-hydroxyflavone

溶媒

dichloromethane

dichloromethane

反応条件

後処理

1. 1
   温度under cooling on ice
2. 2
   その他After completion of the reaction
3. 3
   その他purified water (80 ml)
4. 4
   workup.ADDITIONwas added to the reaction solution
5. 5
   抽出the dichloromethane layer was extracted
6. 6
   乾燥The extract was dried over anhydrous sodium sulfate
7. 7
   workup.DISTILLATIONthe solvent was then distilled away under reduced pressure

実験手順

A dichloromethane solution (4.9 ml) that contained boron tribromide was slowly added to a dichloromethane solution (85 ml) that contained compound 19 (185 mg, 0.489 mmol) while stirring under cooling on ice, and the reaction was then carried out for 30 hours. After completion of the reaction, purified water (80 ml) was added to the reaction solution, and the dichloromethane layer was extracted. The extract was dried over anhydrous sodium sulfate, and the solvent was then distilled away under reduced pressure. The residue was subjected to silica gel column chromatography using ethyl acetate/hexane (1/4) as an elution solvent, so as to obtain a product of interest, 6-bromo-4′-hydroxyflavone (compound 20). Yield: 79 mg (yield constant: 44.3%) 1H NMR (300 MHz, DMSO6) 610.37 (s, 1H), 8.27 (s, 1H), 8.28-8.30 (m, 1H), 7.98 (d, J=8.4 Hz, 2H), 7.61 (d, J=8.7 Hz, 1H), 6.93-6.95 (m, 3H). MS m/z 364 (M+).

出典