Ethanol → ethyl 7-fluoro-3-(1-methyl-1H-imidazol-2-yl)-4-oxo-2-phenyl-1,2,3,4-tetrahydroquinoline-5-carboxylate

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Reaction Conditions

Reaction Steps

A mixture of (E)-4-(benzylideneamino)-6-fluoroisobenzofuran-1(3H)-one (2 g, 7.8 mmol) and 1-methyl-1H-imidazole-2-carbaldehyde (0.949 g, 8.63 mmol) in ethyl propionate (50 mL) was cooled to 0° C. Then a solution of sodium ethoxide in ethanol [sodium (722 mg, 31.37 mmol) in ethanol (30 mL)] was added drop-wise. After the addition, the mixture was stirred at room temperature for 2 hr. The mixture was quenched with water (10 mL) and solvent was removed in vacuum. The residue was dissolved in water, and then extracted with ethyl acetate (100 mL×4). The combined organic layers were washed with brine, dried over anhydrous sodium sulfate, and concentrated to give crude product. The crude product was purified by chromatography (silica gel, petroleum ether/ethyl acetate=10:1 to 1:10) to give the ethyl 7-fluoro-3-(1-methyl-1H-imidazol-2-yl)-4-oxo-2-phenyl-1,2,3,4-tetrahydroquinoline-5-carboxylate (141 mg). 1H-NMR (400 MHz, DMSO-d6) δ (ppm): 1.18-1.22 (t, 3H), 3.31 (s, 3H), 4.17-4.21 (q, 2H), 4.621-4.65 (d, 2H), 5.17-5.20 (d, 1H), 6.48-6.51 (dd, 1H), 6.70-6.73 (m, 2H), 6.86 (s, 1H), 7.24-7.30 (m, 3 H), 7.42-7.44 (t, 2H), 7.76 (s, 1H); LC-MS (ESI) m/z: 394 (M+1)+.

Provenance & Evidence