| 摘要 |
PURPOSE:To obtain a benzoquinone useful as a raw material for preparing tocopherol usable as perfume, drugs, etc. in high yield, by using a specific catalyst, reacting a phenol with hydrogen peroxide with suppressing a secondary reaction. CONSTITUTION:A phenol shown by the formula I (R<1>-R<4> are H, alkyl, or aryl) is reacted with H2O2 which may be seld on the market usually as an aqueous solution preferably in a solvent in the presence of a catalyst consisting of ruthenium and an alkaline earh metal supported on a carrier at 0-100 deg.C preferably at 20-60 deg.C, to give a benzoquinone shown by the formula II. An amount of Ru supported is 0.5-20wt% based on the carrier used, and an amount of the alkaline earth metal is 0.02-2 equivalent based on Ru. The catalyst is prepared by supporting Ru such as ruthenium chloride, etc. on the carrier such as active carbon, silica gel, etc., supporting the alkaline earth metal such as Ba(OH)2, Ca(OH)2, etc. on it. |
