反应详情

To a solution of 3,5-dimethoxybenzaldehyde (1.35 g, 8.12 mmol) and ethyl cyanoacetate (0.92 ml, 8.1 mmol) in ethanol (10 mL) was added piperidine (0.4 mL, 4 mmol). The mixture was stirred at room temperature for approximately 2 h. A precipitate formed, which was collected by filtration and dried to yield approximately 2.12 g of a white solid, which was used directly in the next step. To a solution of 4-hydroxyindole (250 mg, 1.91 mmol) in THF (10 mL) was added sodium hydride (153 mg, 3.80 mmol, 60%) and the mixture was stirred at room temperature for approximately 10 min. To the mixture was added a solution of 3-(3,5-dimethoxyphenyl)-2-cyano-acrylic acid ethyl ester (500 mg, 1.91 mmol, prepared as described above) in THF (2 mL). The mixture was heated at approximately 60° C. overnight. The solvent was evaporated and the residue was purified by flash column chromatography (silica gel, EtOAc:hexane, 1:2), yielding 7 mg (1.1%) of the title compound. 1H NMR (CDCl3): 8.64 (brs, 1H), 7.35-7.24 (m, 2H), 7.19-7.16 (m, 1H), 7.04 (s, 1H), 6.65-6.59 (m, 3H), 3.85 (s, 6H).

1. temperatureThe mixture was heated at approximately 60° C. overnight
2. customThe solvent was evaporated
3. customthe residue was purified by flash column chromatography (silica gel, EtOAc:hexane, 1:2)