Sulfuric Acid → 3,5,6-Trimethyl-2-[phenyl-(3-pyridyl)methyl]-1,4-benzoquinone

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Reaction Steps

To a solution of 1.0 g (5.4 mmol) of phenyl-(3-pyridyl)methanol and 823 mg (5.4 mmol) of 2,3,5-trimethylhydroquinone in 15 ml of dichloromethane, 0.5 ml (9.4 mmol) of concentrated sulfuric acid was added, and refluxed by heating for 2 hours. The reaction mixture was made weakly alkaline with a saturated aqueous solution of sodium hydrogen carbonate, from which the organic phase was separated while the aqueous phase was extracted with chloroform and the extract was combined with the organic phase. The organic phase was washed with water, dried, and oxidized with air, from which the solvent was evaporated off. The residue was purified with silica gel column chromatography (isopropyl ether-ethyl acetate (1:1)), to give 1.25 g (72.7%) of 3,5,6-trimethyl-2-[phenyl-(3-pyridyl)methyl]-1,4-benzoquinone. The physical data are shown in Table 1.

Provenance & Evidence