反应详情

A solution of 200 mL of 25% wt sodium methoxide in methanol (0.84 mol) was diluted with an additional 200 mL of methanol. Acetamidine-HCl (40 g, 0.42 mol) was added to the sodium methoxide solution (white precipitate formed), followed by addition of dimethyl fluoromalonate (70 g, 0.46 mol). The contents were stirred at room temperature overnight, then concentrated in vacuo to dryness. The resulting residue was redissolved in hot water (300 mL). After cooling the aqueous solution to room temperature, concentrated HCl was added slowly until crystal formation (fine white prisms) took place at about pH 5. Concentrated HCl was added dropwise until pH 3, and then the contents were filtered. The isolated crystals were rinsed with 1M HCl and dried under vacuum to provide 5-fluoro-4,6-dihydroxy-2-methylpyrimidine (65.5 g, >100%). LCMS: (M+H)+: 145.

1. concentrationconcentrated in vacuo to dryness
2. dissolutionThe resulting residue was redissolved in hot water (300 mL)
3. temperatureAfter cooling the aqueous solution to room temperature
4. additionconcentrated HCl was added slowly until crystal formation (fine white prisms)
5. additionConcentrated HCl was added dropwise until pH 3
6. filtrationthe contents were filtered
7. washThe isolated crystals were rinsed with 1M HCl
8. customdried under vacuum