Boron tribromide → 6-BROMO-4'-HYDROXYFLAVONE
Reaction equation
B(Br)(Br)[Br:2].I[C:6]1[CH:7]=[C:8]2[C:13](=[CH:14][CH:15]=1)[O:12][C:11]([C:16]1[CH:21]=[CH:20][C:19]([O:22]C)=[CH:18][CH:17]=1)=[CH:10][C:9]2=[O:24]>ClCCl>[Br:2][C:6]1[CH:7]=[C:8]2[C:13](=[CH:14][CH:15]=1)[O:12][C:11]([C:16]1[CH:21]=[CH:20][C:19]([OH:22])=[CH:18][CH:17]=1)=[CH:10][C:9]2=[O:24]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
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+).
Workup
- temperatureunder cooling on ice
- customAfter completion of the reaction
- custompurified water (80 ml)
- additionwas added to the reaction solution
- extractionthe dichloromethane layer was extracted
- dry with materialThe extract was dried over anhydrous sodium sulfate
- distillationthe solvent was then distilled away under reduced pressure
Sources & evidence
- ORD record
- ord-003cbe4ae842490aabef50107c94554a
- Source dataset
- uspto-grants-2012_06
- Patent number
- US08192717B2
Reaction notes
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