Trifluoroacetic acid → 1-Benzyl-5-hydroxy-2-oxo-3-phenyl-1,2-dihydro-[1,7]naphthyridine-6-carboxylic acid (2-formylamino-ethyl)-amide

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Reaction Steps

{2-[(1-Benzyl-5-hydroxy-2-oxo-3-phenyl-1,2-dihydro-[1,7]naphthyridine-6-carbonyl)-amino]-ethyl}-carbamic acid tert-butyl ester (35 mg, 0.068 mmol) was dissolved in CH2Cl2 (2 mL). Trifluoroacetic acid (1 mL) was added, and the mixture was stirred for 2 h. Solvent and excess TFA was removed by evaporation, and to the residue were added THF (3 mL), triethylamine (0.050 mL, 0.34 mmol), and ethyl formate (3 mL). The resulting mixture was refluxed for 4 days. After cooling to r.t., solvent was evaporated. The residue was partitioned between EtOAc and 0.1 M HCl. 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 (0-5% MeOH/CH2Cl2) to give 11.4 mg of the title compound as a light yellow solid. MS: (+) m/z 443.37 (M+1)

Provenance & Evidence