Phosphorus oxychloride → 4-Chloro-2-(3-chlorophenyl)-6-(trifluoromethyl)pyrimidine
Reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([C:8]2[NH:13][C:12](=O)[CH:11]=[C:10]([C:15]([F:18])([F:17])[F:16])[N:9]=2)[CH:5]=[CH:6][CH:7]=1.O=P(Cl)(Cl)[Cl:21]>>[Cl:21][C:12]1[CH:11]=[C:10]([C:15]([F:18])([F:17])[F:16])[N:9]=[C:8]([C:4]2[CH:5]=[CH:6][CH:7]=[C:2]([Cl:1])[CH:3]=2)[N:13]=1Participants
3
Conditions
- Temperature
- 100 °C
Procedure
A 250-mL round bottom flask was charged with 2-(3-chlorophenyl)-6-(trifluoromethyl)pyrimidin-4(3H)-one (3.60 g, 13.1 mmol). POCl3 (14.4 mL, 157 mmol) was cautiously added at 0° C. The resulting mixture was stirred at 100° C. for 3.5 h. After cooling to room temperature, the mixture was concentrated under reduced pressure. The residue was dissolved in dichloromethane (50 mL) and treated with aqueous sodium, bicarbonate until the pH˜8. The aqueous layer was extracted with dichloromethane (4×25 mL). The combined organic extract was washed the saturated sodium chloride (20 mL), dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica chromatography using hexanes/dichloromethane (3:1) as eluent to afford the title compound (3.36 g, 87%) as a white solid. MW=293.07. 1H NMR (CDCl3, 500 MHz) δ 8.49 (t, J=1.5 Hz, 1H), 8.39 (dt, J=8.0, 1.5 Hz, 1H), 7.57 (s, 1H), 7.53 (ddd, J=8.0, 2.0, 1.0 Hz, 1H), 7.45 (t, J=8.0 Hz, 1H).