Phosphorus oxychloride → 4-Chloro-2-methoxy-6-methylpyrimidine
Reaktionsgleichung
[CH3:1][O:2][C:3]1[NH:8][C:7](=O)[CH:6]=[C:5]([CH3:10])[N:4]=1.O=P(Cl)(Cl)[Cl:13]>>[Cl:13][C:7]1[CH:6]=[C:5]([CH3:10])[N:4]=[C:3]([O:2][CH3:1])[N:8]=1Komponenten
3
Versuchsvorschrift
2-Methoxy-6-methylpyrimidin-4(3H)-one (12 g, 85.71 mmol, 1 eq) was heated for 30-40 min at 100° C. in POCl3 (85 ml). The reaction mixture was then concentrated and diluted with ice-water (100 ml). The aqueous phase was rendered alkaline (pH˜9) with NaHCO3 and extracted with ethyl acetate (2×200 ml). The combined organic phases were washed with saturated sodium chloride solution (100 ml), dried over sodium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel, 2% ethyl acetate/hexane). The desired product was in the form of a light-yellow solid. Yield: 2.3% (300 mg, 1.8987 mmol) after 2 stages