Phosphorus oxychloride → 2-Methoxy-4,6-dimethyl-5-nitropyrimidine

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Reaction Conditions

Reaction Steps

4,6-Dimethyl-5-nitropyrimidin-2-ol (18.4 g, 108 mmol) wad added portionwise to a stirred phosphoryl chloride at 0° C., and the mixture was stirred at 100° C. for 80 min. The mixture was concentrated in vacuo, and methanol (180 mL) was added to the residue carefully at 0° C. Sodium methoxide (28% solution in methanol, 68.8 g, 357 mmol) was added dropwise to a stirred mixture at 0° C., and the mixture was stirred at 0° C. for 10 min. The mixture was diluted with aqueous saturated ammonium chloride and concentrated in vacuo. The residue was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel eluting with a 5-20% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give the title compound as a yellow wax (13.0 g, 71.0 mmol, 66%).

Provenance & Evidence