反应详情

A mixture of 1-benzyl-5-hydroxy-8-(1-methyl-1H-pyrazol-4-yl)-2-oxo-3-phenyl-1,2-dihydro-[1,7]naphthyridine-6-carboxylic acid methyl ester (52 mg, 0.11 mmol), β-alanine (596 mg, 6.7 mmol) and NaOMe solution (10 mL, 5.0 mmol, 0.5 M in MeOH) was refluxed for 16 h. After the mixture was cooled to r.t., the solvent was evaporated in vacuo. The residue was partitioned between EtOAc and water. 1 M HCl was added with vigorous stirring until pH was about 3-4. The aqueous layer was extracted with additional EtOAc, and the organic layers were combined, dried over MgSO4 and concentrated. The crude product was purified by silica gel chromatography (5-100% EtOAc/hexanes+1% AcOH). The product isolated was dissolved in saturated NaHCO3 and washed several times with ether. The aqueous layer was acidified to pH about 3-4, and the resulting precipitate was isolated by filtration to give 26 mg of the title compound. MS: (+) m/z 524.37 (M+1).

1. temperaturewas refluxed for 16 h
2. customthe solvent was evaporated in vacuo
3. customThe residue was partitioned between EtOAc and water
4. addition1 M HCl was added
5. extractionThe aqueous layer was extracted with additional EtOAc
6. dry with materialdried over MgSO4
7. concentrationconcentrated
8. customThe crude product was purified by silica gel chromatography (5-100% EtOAc/hexanes+1% AcOH)
9. customThe product isolated
10. washwashed several times with ether
11. customthe resulting precipitate was isolated by filtration