反应详情

Sodium ethoxide (19.99 g, 293.72 mmol, 2 eq) was dissolved in anhydrous ethanol (210 ml) at 50° C. To the solution was added ethyl 2-cyanoacetate (15.67 ml, 146.86 mmol, 1 eq) then 1-propylurea (15 g, 146.86 mmol, 1 eq), and the mixture was stirred at reflux for 24 hours. The solvent was evaporated under reduced pressure, and the residue was dissolved in water (70 ml). The pH of the solution was adjusted to ˜7 by using concentrated HCl. The light yellow solid formed was collected by filtration, washed with water, and dried under vacuum to afford 23.82 g of the desired product (96% yield): The desired isomer was determined via 2D-NMR; 1H NMR (400 MHz, DMSO-d6) δ 10.3 (1H), 6.79 (2H), 4.52 (1H), 3.68-3.70 (2H), 1.50 (2H), 0.85 (3H); m/z (ES+) 170.18

1. temperatureat reflux for 24 hours
2. customThe solvent was evaporated under reduced pressure
3. dissolutionthe residue was dissolved in water (70 ml)
4. customThe light yellow solid formed
5. filtrationwas collected by filtration
6. washwashed with water
7. customdried under vacuum