Ethyl 4-hydroxy-5-pyrimidinecarboxylate was prepared as follows:
Add 1.6g (70mmol) of sodium metal to 50mL of anhydrous ethanol, wait for the reaction to be complete, ice-water bath cooled to 0??C, add 7.3g (70mmol) formamidine acetate, followed by the slow dropwise addition of 15.1g (70mmol) diethyl ethoxymethylidene malonate , the reaction was continued at 0 ??C for 3 h. 1.6 g (70 mmol) of sodium metal dissolved in 50 mL of anhydrous ethanol was cooled to 0 ??C and added dropwise to the above reaction solution. After the reaction at room temperature overnight, the majority of the ethanol was removed to give a yellow solid. It was added to 100mL of water, heated until dissolved, and when cooled, 100mL of ether was added, stirred thoroughly, and the ether was separated to remove the raw material that had not reacted completely. Continue to heat to dissolve, use concentrated hydrochloric acid to adjust the pH of the solution to 2 ~ 3, after cooling, precipitated light yellow solid, filtered, vacuum dried, and finally obtained 9.4g of light yellow solid, the yield was 80%.
