Triethylamine → 7-{4-[4-(2,3-Dichloro-phenyl)-piperazin-1-yl]-butoxy}-6-fluoro-3,4-dihydro-1H-[1,8]naphthyridin-2-one

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Reaction Steps

To a suspension of 1-(2,3-dichloro-phenyl)-piperazine hydrochloride (0.80 g, 3.0 mmol) in 1,2-dichloroethane (10 mL) was added triethylamine (0.61 mL, 6.0 mmol). The mixture was stirred for 30 min at room temperature and 4-(3-fluoro-7-oxo-5,6,7,8-tetrahydro-[1,8]naphthyridin-2-yloxy)-butyraldehyde (0.76 g, 3.0 mmol) was added as a suspension in 1,2-dichloroethane (5 mL). The mixture was stirred for 30 min and NaBH(OAc)3 (0.89 g, 4.2 mmol) was added as a solid. The reaction was stirred at room temperature for 4 h. The mixture was poured into EtOAc/dichloroethane and washed with saturated NaHCO3 and brine. The organic layer was washed with aqueous citric acid (pH 4.5) and brine, dried over Na2SO4 and concentrated to a slurry. Et2O was added and the solid was collected by filtration. Purification by liquid chromatography (Biotage 40S, gradient of CH2Cl2 to 10% MeOH/CHCl3) gave the title compound as a white solid (738 mg, 1.58 mmol, 53%). MS: APCI: M+1: 467.3 (Exact Mass: 466.13).

Provenance & Evidence