反应详情

温度

20 °C

A solution of 7-amino-4-oxo-3H-pyrido[4,3-d]pyrimidine (1.00 g, 6.17 mmol) in 60% HBF4 (25 mL) at 0° C. is treated with solid NaNO2 (0.85 g, 12.3 mmol, added in portions over 2 h), and is then stirred at 0° C. for a further 1 h and at 20° C. for 30 min. The resulting mixture is ice-cooled, neutralized with saturated aqueous Na2CO3, and extracted with EtOAc (4×100 mL) The extract is washed with water, then filtered through silica gel (EtOAc) to give 7-fluoro-4-oxo-3H-pyrido[4,3-d]pyrimidine (0.48 g, 47%) as a cream solid. 1H NMR (DMSO) δ 12.69 (1H, brs), 9.01 (1H, s), 8.31 (1H, s), 7.34 (1H, s)

1. temperaturecooled
2. extractionextracted with EtOAc (4×100 mL) The extract
3. washis washed with water
4. filtrationfiltered through silica gel (EtOAc)