Hydrochloric Acid → 7-(2,4-Dimethoxy-benzyl)-4-hydroxy-8-oxo-7,8-dihydro-[2,7]naphthyridine-3-carboxylic acid methyl ester

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Reaction Steps

1-(2,4-Dimethoxy-benzyl)-3-{[methoxycarbonylmethyl-(toluene-4-sulfonyl)-amino]-methyl}-2-oxo-1,2-dihydro-pyridine-4-carboxylic acid ethyl ester (4.2 g, 7.34 mmol) was dissolved in MeOH (160 mL). NaOMe solution (5 mL, 22 mmol, 25 wt % in MeOH) was added, and the mixture was stirred overnight. 1 M HCl was added to acidify the mixture, and the resulting suspension was extracted with CH2Cl2. The organic layer was dried over MgSO4 and concentrated. The residue was chromatographed (5-80% EtOAc/hexanes+2% AcOH) to give 2.45 g of the title compound as a yellow solid. MS: (+) m/z 371.28 (M+1).

Provenance & Evidence