Potassium Carbonate → 1-[5-(Benzyloxy)-3-methyl-1-benzofuran-2-yl]-2-methylpropan-1-one

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Reaction Steps

To a solution (200 mL) of 1-[5-(benzyloxy)-2-hydroxyphenyl]ethanone (16.1 g) synthesized in Example A82(1) in N,N-dimethylformamide were added at room temperature potassium carbonate (27.6 g) and 1-bromo-3-methylbutan-2-one (14.3 g) synthesized in Example A75(1), and the mixture was stirred for 15 hr. The reaction mixture was filtered through celite, water (200 mL) was added and the mixture was extracted with diethyl ether (100 mL×2). The extract was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was dissolved in N,N-dimethylformamide (100 mL), and DBU (9.9 mL) was added at room temperature. The reaction mixture was stirred at 100° C. for 1 hr. The reaction mixture was allowed to cool to room temperature, 1N hydrochloric acid (150 mL) was added, and the mixture was extracted with diethyl ether (100 mL×2). The extract was washed with water, saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was recrystallized from ethanol-diisopropyl ether to give the title object compound (11.7 g, 57%) as pale-yellow crystals.

Provenance & Evidence