反应详情

温度

100 °C

A 250-mL round bottom flask was charged with 2-(3-chlorophenyl)-6-ethylpyrimidin-4(3H)-one (9.3 g, 39.8 mmol, 1 eq.). POCl3 (50 mL, 536 mmol, 13.4 eq.) was cautiously added at 0° C. The resulting mixture was stirred at 100° C. for 5 hr. After cooling to room temperature, the mixture was added slowly dropwise to cold aq. NaHCO3. NaOH was added to keep the pH˜0.7 during quenching. The mixture was extracted with ethyl acetate. The organic extract was dried over sodium sulfate, filtered and concentrated under reduced pressure. Purification by silica gel chromatography using dichloromethane/ethyl acetate as eluent afforded 4-chloro-2-(3-chlorophenyl)-6-ethylpyrimidine (9.3 g, 99% yield) as a white solid. 1H NMR (CD3OD, 500 MHz) δ 8.32 (s, 1H), 8.28 (d, J=7.5 Hz, 1H), 7.50-7.46 (m, 1H), 7.45-7.40 (m, 1H), 7.27 (s, 1H), 2.83 (q, J=7.5 Hz, 2H), 1.34 (t, J=7.5 Hz, 3H).

1. temperatureAfter cooling to room temperature
2. customduring quenching
3. extractionThe mixture was extracted with ethyl acetate
4. extractionThe organic extract
5. dry with materialwas dried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customPurification by silica gel chromatography