Reacción #302856

Ecuación de reacción

boron tribromide

compound 19

6-iodo-4′-methoxyflavone

→

compound 20

6-bromo-4′-hydroxyflavone

Disolventes

dichloromethane

dichloromethane

Condiciones de reacción

Tratamiento posterior

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

Procedimiento

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+).

Fuente