A mixture was prepared by mixing 0.52 g of magnesium, 7.5 g of 3,4-dimethoxy-2,5-bismethoxymethoxy-6-methylbromobenzen and 0.2 ml of ethyl bromide into 30 ml of tetrahydrofurananhydride. The mixture was refluxed by heating until magnesium in the mixture disappears. The reaction mixture was cooled, 4.4 g 2,6-di-tert-butyl-p-benzoquinone was added thereinto, stirred for 2 hours, 1.5 g of lithium aluminium hydroxide was added thereinto, and stirred overnight at room temperature. An excess of hydrides in the reaction mixture was decomposed with ethylacetate, wherein 20 ml of 10% hydrochloric acid was added. The reaction mixture was stirred for 4 hours at room temperature, refluxed by heating for futher 2hours, cooled and extracted with diethylether. The extract was washed with 10% water solution of sodium hydrogencarbonate and an aqueous solution saturated with NaCl in turn, dried with sodium sulfate and concentrated. The concentrate was injected into a silica gel column-chromatography. The fraction eluted with the solvent (n-hexane:ethyl acetate=20:1) was concentrated, dissolved into 30 ml of methanol and stirred in addition of water solution of ferric chloride for 1hour, and then methanol in the reaction mixture was removed. The reactant was extracted with diethylether, and the extract was washed with an aqueous solution saturated with NaCl, dried with sodium sulfate and concentrate. The concentrated was recrystallized from ethylacetate/n-hexane to yield 0.5 g of reddish orange prism 2-(3,5-di-tert-butyl-4-hydroxyphenyl-5,6-dimethoxy-3-methyl-p-benzoquinone having a mp of 147.0°-148.0° C.
