Ethyl Acetate → 4-{5-[5-fluoro-2-oxo-1,2-dihydro-indol-(3E)-ylidene]-2,2-dimethyl-2,5-dihydro-furan-3-yl}-benzaldehyde

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Reaction Conditions

Reaction Steps

To a mixture of 3-[4-bromo-5,5-dimethyl-5H-furan-(2E)-ylidene]-5-fluoro-1,3-dihydro-indol-2-one (6.5 g, 20 mmol), 4-formyl phenyl boronic acid (3.6 g, 24 mmol) in THF (250 mL), was added a solution of potassium carbonate (27.6 g, 200 mmol) in water (25 mL). The resulting mixture was deoxygenated with nitrogen, and palladium(0)tetrakis(triphenylphosphine) (1.15 g, 1.0 mmol, 5 mol %) then added. The reaction mixture was heated at 65° C. for 20 hours and then it was allowed to cool to room temperature. Ethyl acetate (800 mL) was added. The organic phase was washed with water (200 mL×2), dried over sodium sulfate and evaporated to give crude product. The purification first by column (SiO2) chromatography (5% CH3OH/CH2Cl2) and then by titration with ethyl acetate led to 4-{5-[5-fluoro-2-oxo-1,2-dihydro-indol-(3E)-ylidene]-2,2-dimethyl-2,5-dihydro-furan-3-yl}-benzaldehyde as a deep red solid (3.6 g, yield 51.5%).

Provenance & Evidence