Trimethylhydroquinone → Ethyl-5-[1-(3,5,6-trimethyl-1,4-benzoquinon-2yl)ethyl]-2-thienylacetate

Participants

Reaction Conditions

Reaction Steps

Trimethylhydroquinone (1.5 g, 10 mmole) and 5-(1-hydroxyethyl)-2-thienylacetic acid (2.5 g, 8.5 mmole) were added to 50 ml of toluene, and D-camphorsulfonic acid (0.2 g) was added to the mixture, followed by heating at 50° C. for 6 hours with stirring. After cooling, the reaction solution was concentrated under reduced pressure, and the residue was dissolved in THF. An aqueous solution of ferric chloride was added to the solution, followed by stirring at room temperature for 10 minutes. The reaction solution was extracted with isopropyl ether, and the organic layer was washed with water, dried and evaporated under reduced pressure. The crude product was purified by silica gel column chromatography using IPE:hexane (1:1) to give ethyl-5-[1-(3,5,6-trimethyl-1,4-benzoquinon-2yl)ethyl]-2-thienylacetate (2.4 g, 72%). Hydrolysis of this compound with 6N hydrochloric acid in THF yielded 5-[1-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)ethyl]-2-thienylacetic acid (2.1 g, 90%). δ 6.69(2H,m), 4.61(1H,m), 3.73(2H,s), 1.98(9H,s), 1.61(3H,d, 7 Hz).

Provenance & Evidence