1,2-Dichloroethane → 3-[(1-Benzyl-5-hydroxy-2-oxo-3-phenyl-8-thiazol-2-yl-1,2-dihydro-[1,7]naphthyridine-6-carbonyl)-amino]-propionic acid methyl ester

Participants

Reaction Steps

A mixture of 1-benzyl-5-hydroxy-2-oxo-3-phenyl-8-thiazol-2-yl-1,2-dihydro-[1,7]naphthyridine-6-carboxylic acid methyl ester (64 mg, 0.14 mmol), 2 M NaOH (3 mL), MeOH (3 mL) and THF (3 mL) was stirred at r.t. overnight. The mixture was concentrated to approximately one-third of its original volume, and then acidified to pH about 3 with 1 M HCl. The resulting suspension was extracted with EtOAc. The organic layer was dried over MgSO4 and concentrated. To the residue were then added HOBt (30 mg, 0.22 mmol), CH2Cl2 (3 mL), and EDC (47 mg, 0.25 mmol), and the resulting mixture was stirred for 10 min. β-Alanine methyl ester HCl salt (31 mg, 0.22 mmol) and Hunig's base (0.1 mL, 0.49 mmol) were added, and the mixture was stirred for 16 h. The mixture was concentrated in vacuo, and the residue was purified by silica gel chromatography (5-40% EtOAc/hexanes+1% AcOH) to give 28 mg of the title compound. MS: (+) m/z 541.31 (M+1).

Provenance & Evidence