Sodium Carbonate → ethyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethyl thiophen-3-yl]-2-oxoacetate

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Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere, sodium carbonate (78 mg, 0.7 mmol), palladium tetrakis(triphenylphosphine) (81 mg, 0.07 mmol) and 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)chroman (182 mg, 0.7 mmol) were added to a solution of ethyl (4-bromo-2,5-dimethyl-thiophen-3-yl)-oxo-acetate (17c) (200 mg, 0.69 mmol) in a mixture of water (3.5 mL) and N,N-dimethylformamide (11 mL). The mixture was heated at 110° C. for 1 hour. The mixture was then cooled at room temperature, concentrated in vacuo and water (30 mL) was added. The aqueous layer was extracted with ethyl acetate (2×30 mL). The organic layer was washed with brine (30 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate 80/20) to afford the desired product (17d) as a white solid (90 mg, 0.26 mmol, 38%).

Provenance & Evidence