Hydrochloric Acid → Ethyl (2,3,5,6-tetrachloro-1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl)acetate

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Reaction Steps

Under nitrogen atmosphere, 6 mL of THF was added to 1.22 g (2 mmol, 0.6 equivalent) of (BrZnCH2COOEt.THF)2. Under argon atmosphere, a solution of 0.82 g (3.33 mmol) of 2,3,5,6-tetrachloro-1,4-benzoquinone in 26 mL of THF was added dropwise while stirring at 0˜5° C. The mixture was stirred at 20˜25° C. for 1 hour. 10 mL of 1N hydrochloric acid was added dropwise at 20° C. or lower, followed by dilution with 50 mL of ethyl acetate. Then, the layers were separated. The organic layer was washed successively with 5 mL (×2) of 1N hydrochloric acid, 5 mL of water, 10 mL (×2) of an aqueous saturated sodium bicarbonate solution, and 5 mL (×2) of an aqueous saturated sodium chloride solution. After washing, the organic layer was dried with anhydrous magnesium sulfate. Concentration under reduced pressure afforded 1.04 g of the desired product (yield 94%).

Provenance & Evidence