p-Toluenesulfonic acid → HCID 56637317, compound

Participants

Reaction Steps

To a solution of 6-(5-carboxy-3-methyl-2-pentenyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone (93 mg) in methanol (3 ml) was added p-toluene sulfonic acid (10 mg). The mixture was stirred for 4 hours. The solvent was evaporated off under reduced pressure. The residue was dissolved in diethylether. The solution was washed with water and then dried. The solvent was evaporated off under reduced pressure. The residue was subjected to a column chromatography using silica-gel (3 g). From the fractions eluted with carbon tetrachloride-ethyl acetate (5:1) was obtained 2,3-dimethoxy-6-(5-methoxycarbonyl-3-methyl-2-pentenyl)-5-methyl-1,4-benzoquinone (84 mg). This product was treated in a conventional manner to produce 2,3-dimethoxy-6-(5-methoxycarbonyl-3-methyl-2-pentenyl)-5-methylhydroquinone, which was dissolved in pyridine (0.4 ml). The solution was cooled to about -10° C., to which was added chlorosulfonic acid (120 μl). The mixture was stirred for two days at room temperature. The reaction solution was made to pH 8- 9 with 1N potassium carbonate, then unreacted substances were removed by extraction with diethylether. The aqueous phase was subjected to evaporation to dryness under reduced pressure. The residue was subjected to column-chromatography using silica-gel (3 g). From the fractions eluted with methanol-chloroform (2:5) was obtained a mixture (24 mg) of potassium salts of 2,3-dimethoxy-6-(5-methoxycarbonyl)-3-methyl-2-pentenyl)-5-methylhydroquinone 1-sulfate and 4-sulfate.

Provenance & Evidence