Реакция #302856

Уравнение реакции

boron tribromide

compound 19

6-iodo-4′-methoxyflavone

→

compound 20

6-bromo-4′-hydroxyflavone

Растворители

dichloromethane

dichloromethane

Условия реакции

Обработка

1. 1
   Температураunder cooling on ice
2. 2
   ДругоеAfter completion of the reaction
3. 3
   Другоеpurified water (80 ml)
4. 4
   workup.ADDITIONwas added to the reaction solution
5. 5
   Экстракцияthe dichloromethane layer was extracted
6. 6
   СушкаThe extract was dried over anhydrous sodium sulfate
7. 7
   workup.DISTILLATIONthe solvent was then distilled away under reduced pressure

Методика

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+).

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