反应详情

In methanol (5.4 l) was dissolved 10-(2-hydroxy-3,4-dimethoxy-6-methylphenyl)decan-1-ol (271 g), to which was added an aqueous solution of disodium nitrosodisulfonate (6.7 l, content 0.359 mol./l) synthesized by means of electrolytic oxidation. The mixture was stirred for two hours while keeping the temperatures at 50°±2° C. After confirmation of disappearance of the starting material by thin-layer chromatography, water (8.6 l) was added to the reaction mixture, followed by extraction twice with toluene (5.5 and 2.7 l). The toluene layers were combined and washed with water. The toluene layer was concentrated under reduced pressure to obtain a crude product, 6-(10-hydroxydecyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone (288 g, content 94.8%, yield 96.9%). This crude product (20 g) was recrystallized from a mixture of toluene (60 ml) and n-hexane (180 ml). The crystals were dissolved in toluene (60 ml), and the solution was allowed to pass through a precoated layer of activated alumina (30 g). The filtrate was concentrated under reduced pressure, and the concentrate was recrystallized again from a mixture of toluene (55 ml) and n-hexane (165 ml). The crystals were further recrystallized from 50% ethanol (108 ml), followed by drying to obtain 6-(10-hydroxydecyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone (16.2 g) as orange-yellow crystals, m.p. 54.0° C.

1. customsynthesized by means of electrolytic oxidation
2. customat 50°±2° C
3. extractionfollowed by extraction twice with toluene (5.5 and 2.7 l)
4. washwashed with water
5. concentrationThe toluene layer was concentrated under reduced pressure