Synthesis
Diethyl ethoxymethylenemalonate (35.0 g, 162 mmol) and trifluoroacetic acid (18 g, 162 mmol) were used as raw materials, which were dissolved in ethanol (200 mL) and sodium ethoxide (11.0 g, 162 mmol) was added. The reaction mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction mixture was concentrated and water (48 mmol) was added. The resulting solid was collected by filtration, washed sequentially with ether (300 mL) and water (200 mL), and dried to give ethyl 4-hydroxy-2-trifluoromethylpyrimidine-5-carboxylate (21 g, 50% yield). The melting point of the product was >220 °C (decomposition); 1H NMR (DMSO-d6) δ 8.38,4.16 (q, 2H), 1.25 (q, 3H).
