Urea → HCID 10217675, compound

Participants

Reaction Steps

3-(3,5-Dimethoxyphenyl)-2-{4-[4-(2-ethoxycarbonylvinyl)-phenoxy]-phenyl}-acrylic acid (4, 2.37 g, 5.0 mmol) was dissolved in a mixture of ethanol-dioxane (2:1, 150 mL), and palladium charcoal (10%, 500 mg) was added. The mixture was stirred under hydrogen for 15 hr. Catalyst was then removed by filtration, and solvent was evaporated under reduced pressure to yield 3-(3,5-dimethoxy-phenyl)-2-{4-[4-(2-ethoxycarbonylethyl)-phenoxy]-phenyl}-propionic acid (18) quantitatively. Urea (0.21 g, 3.58 mmol) was dissolved in sodium ethoxide (2.7 M, 2.2 mL, 5.92 mmol) at 80° C. under argon, and to this a solution of 18 (1.13 g, 2.37 mmol) in anhydrous ethanol (15 mL) was added and heated at this temperature for 13 hr. Ethanol was evaporated under reduced pressure, water (20 mL) was added, acidified to pH 1 by 5% aqueous HCl and extracted with ethyl acetate (50 mL). The organic layer was washed with water (2×25 mL), brine (2×20 mL), dried over anhydrous magnesium sulfate and evaporated. The crude product was purified by silica gel chromatography and eluted with hexane-ethyl acetate (3:7) containing acetic acid (1%), followed by recrystallization from ethanol. Yield: 256 mg, 22.8%.

Provenance & Evidence