| 摘要 |
PURPOSE:To obtain the titled substance which is a synthetic intermediate for various substances useful as medicines in high yield at a low cost, by oxidizing 3-methyl-8-propenylflavone, etc. in the presence of a phase transfer catalyst in a solvent consisting essentially of acetone without using pyridine. CONSTITUTION:3-Methyl-8-propenylflavone or 3-methyl-8-(2-methylpropenyl)flavone as a raw material is oxidized in the presence of a phase transfer catalyst in a solvent consisting essentially of acetone, e.g. a mixture of one kind of solvent such as acetone or methyl ethyl ketone, etc. with one kind of solvent such as water, aqueous alkali (KHCO3, etc.) or benzene, etc. at -5-+20 deg.C, preferably -5-10 deg.C to afford the aimed compound. Tetrabutylammonium hydrogensulfide, etc. may be used as the phase transfer catalyst, and the amount thereof to be used is 0.1-0.2 equivalent based on the above-mentioned raw material compound. Potassium permanganate, etc. may be used as the oxidizing agent.
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