2,3-dimethoxy-5-methyl-1,4-benzoquinone ú¿ó±ú®preparation method

Abstract

The invention relates to a process for preparing 2,3-dimethoxy-5- methyl-1,4- benzophenone (I) by subjecting raw material 3,4,5-trimethoxytoluene (II) first with phosphorus oxytrichloride and N,N-dimethyl formamide to Vilsmeier reaction, obtaining 2,3,4-trimethoxyl-6- methyl- benzaldehyde (III) by introducing aldehydo onto phenyl ring, and oxidizing (III) into phenol (IV) with H2O2 at the presence of small amount organic acid catalysis at room temperate.

Description

technical field [0001] The invention belongs to the field of organic chemistry, and is a preparation method of 2,3-dimethoxy-5-methyl-1,4-benzoquinone (I) [0002] Background technique [0003] 2,3-dimethoxy-5-methyl-1,4-benzoquinone (I) is a synthetic coenzyme Q series compound (CoQ 1-10 ) is an important starting material. Japanese Patent (Japanese Patent Application No. 54-106440) describes the use of 60% H 2 o 2 A method of directly oxidizing 3,4,5-trimethoxytoluene (II) to prepare (I) at 0°C, but this method requires a large amount of strong acid: trifluoroacetic acid as a catalyst, which is not only expensive but also corrosive to industrial equipment Seriously, the yield is not high (68%). Japanese Patent (Japanese Patent Application No. 56-75450) also describes the use of (NH 4 ) 2 S 2 o 8 (II) is directly oxidized to prepare (I), but this method still needs to be catalyzed and extracted with a large amount of concentrated sulfuric acid, the operation ...

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Problems solved by technology

Japanese Patent (Japanese Patent Application No. 54-106440) describes the use of 60% H 2 o 2 A method of directly oxidizing 3,4,5-trimethoxytoluene (II) to prepare (I) at 0°C, but this method requires a large amount of strong acid: trifluoroacetic acid as a catalyst, which is not only expensive but also corrosive to industrial equipment Seriously, the yield is not high (68%)

Japanese Patent (Japanese Patent Application No. 56-75450) also describes the use of (NH 4 ) 2 S 2 o 8 The method of preparing (I) by direct oxidation of (II), but this method still needs to be catalyzed and extracted with a large amount of concentrated sulfuric acid, the operation is cumbersome and the yield is low (55%), and it is not suitable for large-scale industrial production

Chinese patent ( 1008053) improves the above-mentioned (NH 4 ) 2 S 2 o 8 Oxidation method, the yield has been improved, but it still needs to use a large amount of glacial acetic acid-concentrated sulfuric acid as a catalyst, and the corrosion of industrial equipment is still relatively large

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