PROCESS OF PRODUCING 2,3-DIMETHOXY-5-METHYL-1,4-BENZOQUINONE Russian patent published in 2017 - IPC C07C46/02 C07C50/28 B01J31/34 B01J31/36 

FIELD: chemistry.

SUBSTANCE: invention relates to the method of producing 2,3-dimethoxy-5-methyl-1,4-benzoquinone, a key intermediate in the synthesis of ubiquinones (coenzymes of the Q_n series), in particular of coenzyme Q₁₀, widely used in medical practice and cosmetology, as well as its synthetic analogue - idebenone - a drug for the treatment of Alzheimer's disease. The method consists in oxidizing 3,4,5-trimethoxytoluene with hydrogen peroxide in an organic solvent medium. Herewith the acid tetrabutylammonium salts of the vanadium-containing polyoxo-tungstate (C₄H₉)₄N)_5-nH_n[γ-PV₂W₁₀O₄₀], where the number of protons n in the cationic part of the polyox-tungstate varies from 1 to 2, as co-catalyst, HClO₄ with respect to the catalyst, 0.5-1 equivalents, as the organic solvent, preferably acetonitrile is used, the process is carried out at the temperature of, at least, 30°C, at the molar ratio of 3,4,5-trimethoxytoluene: the catalyst is not lower than 40 and the concentration of 3,4,5-trimethoxytoluene is not higher than 0.4M, an aqueous solution of hydrogen peroxide with a peroxide content of, at least, 30 wt %, the process is carried out at the molar ratio of hydrogen peroxide: 3,4,5-trimethoxyphenol not less than 2.

EFFECT: desired product in high yield without the formation of a large amount of by-products.

2 cl, 1 tbl, 23 ex