反应详情

温度

70 °C

5-Bromo-4-fluoro-2-nitro-benzaldehyde (1.50 g, 6.05 mmol) and ethyl pyruvate (737.4 mg, 6.35 mmol) in ethanol (15 mL) was added via canula to zinc(II)chloride (4.12 g, 30.24 mmol), tin(II)chloride (5.73 g, 30.24 mmol), and activated 4 Å molecular sieve pellets (1.50 g) in ethanol (15 mL) under argon. The mixture was heated at 70° C. in an oil bath for four hours, then allowed to cool to room temperature, and carefully quenched with saturated sodium bicarbonate. Ethyl acetate was added and the mixture was filtered through Celite®. The filtrate was extracted with ethyl acetate and the organic layer was dried over anhydrous magnesium sulfate, then filtered and concentrated. The residue was purified by silica gel chromatography eluting with 1:6 ethyl acetate:hexanes to give 368.5 mg (20%) of ethyl 6-bromo-7-fluoro-2-quinolinecarboxylate as a solid. 1H NMR (400 MHz, d6-DMSO): δ 8.63 (d, J=8 Hz, 1H), 8.58 (d, J=9 Hz, 1H), 8.15 (s, 1H), 8.13 (s, 1H), 4.42 (q, J=7 Hz, 2H), 1.37 (t, J=7 Hz, 3H). ESI-LCMS m/z 297 (M+H)+.

1. temperatureto cool to room temperature
2. customcarefully quenched with saturated sodium bicarbonate
3. additionEthyl acetate was added
4. filtrationthe mixture was filtered through Celite®
5. extractionThe filtrate was extracted with ethyl acetate
6. dry with materialthe organic layer was dried over anhydrous magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by silica gel chromatography
10. washeluting with 1:6 ethyl acetate