反应详情

Phosphorus oxychloride (20 ml, 0.21 mol) was added to 2.0 g (7.6 mmol) of 1-n-butyl-4-hydroxy-3-nitro-1,8-naphthyridin-2(1H)-one [J-Heterocyclic Chem., 22, 193 (1985)], and the mixture was heated to reflux for 30 minutes. After cooling to room temperature, the solvent was distilled off under reduced pressure and ice water was added to the resulting residue. The mixture was neutralized with 4N aqueous solution of sodium hydroxide, followed by extraction with chloroform. The organic layer was dried over anhydrous sodium sulfate, and then filtered. The solvent was distilled off under reduced pressure. The obtained residue was purified by silica gel column chromatography (developing solvent: chloroform/methanol=20/1) to give 1.2 g (yield 56%) of Compound d as colorless crystals.

1. temperaturethe mixture was heated
2. temperatureto reflux for 30 minutes
3. distillationthe solvent was distilled off under reduced pressure and ice water
4. additionwas added to the resulting residue
5. extractionfollowed by extraction with chloroform
6. dry with materialThe organic layer was dried over anhydrous sodium sulfate
7. filtrationfiltered
8. distillationThe solvent was distilled off under reduced pressure
9. customThe obtained residue was purified by silica gel column chromatography (developing solvent: chloroform/methanol=20/1)