反应详情

A 1-L round bottomed flask was charged with 3-chlorobenzimidamide (23.9 g, 154 mmol, 1 eq.), ethyl 3-oxopentanoate (27.8 g, 193 mmol, 1.25 eq.), and ethanol (500 mL). To the mixture was added sodium methoxide (10.0 g, 185 mmol, 1.20 eq.). The resulting mixture was stirred under reflux for 20 hr. After cooling to room temperature, the mixture was evaporated under reduced pressure to 50 mL. The residual slurry was cautiously treated with 2N HCl (219 mL). Solid was collected by filtration and washed with water followed by ether to afford 2-(3-chlorophenyl)-6-ethylpyrimidin-4(3H)-one (9.3 g, 39% yield), which was carried forward into the next step without further purification. 1H NMR (CD3OD, 500 MHz) δ 8.07 (s, 1H), 7.96 (d, J=8.0 Hz, 1H), 7.62-7.58 (m, 1H), 7.52 (t, J=8.0, Hz, 1H), 6.27 (s, 1H), 2.66 (q, J=7.5 Hz, 2H), 1.29 (t, J=7.5 Hz, 3H).

1. temperatureunder reflux for 20 hr
2. customthe mixture was evaporated under reduced pressure to 50 mL
3. additionThe residual slurry was cautiously treated with 2N HCl (219 mL)
4. filtrationSolid was collected by filtration
5. washwashed with water