The ethanolic solution of sodium ethoxide was cooled to 0 °C under argon protection. Under continuous stirring, diethyl 2-formylsuccinate was slowly added. after 5 minutes, the corresponding formamidine acetate was added drop by drop while maintaining the condition of 0°C. Subsequently, the reaction mixture was warmed up to room temperature and stirred continuously for 3 days. After completion of the reaction, 5% aqueous hydrogen chloride solution was added and stirring was continued for 30 minutes. After addition of appropriate amount of water, ethanol was removed by distillation under reduced pressure at 30 °C. Finally, the precipitate was collected by filtration to afford the target product ethyl 4-hydroxy-5-pyrimidineacetate (Compound 1, where X = H, Me, Ph, SMe; Y = H, R1 = Et).
