反应详情

温度

80 °C

To a solution of 3-bromo-6-chloro-pyridine-2-carboxylic acid ethyl ester (22, 8.0 g, 30.24 mmol) and 2-bromo-5-hydroxy-benzaldehyde (7.29 g, 36.29 mmol) in DMF (100 mL) was added cesium carbonate (22.6 g, 69.55 mmol). The resulting mixture was heated at 80° C. overnight. DMF was removed under reduced pressure, and the residue was diluted with EtOAc (200 mL), washed with water (2×50 mL) and brine (50 mL) solution. The combined organic layers were dried over Na2SO4, filtered, and concentrated to give crude product which was purified by column chromatography (Silica gel 20% EtOAc in hexane) to yield title compound 23 (4.0 g, 31%) as transparent oil. 1H NMR 400 MHz (DMSO-d6) δ: 10.18 (s, 1H), 8.27 (d, J=8.6 Hz, 1H), 7.87 (d, J=7.6 Hz, 1H), 7.65 (s, 1H), 7.51 (dd, J=8.7, 2.9 Hz, 1H), 7.26 (d, J=8.9 Hz, 1H), 4.29 (q, J=7.1 Hz, 2H), 1.25 (t, J=7.0 Hz, 3H); MS (ES) m/z: 430 (M+1)+.

1. customDMF was removed under reduced pressure
2. additionthe residue was diluted with EtOAc (200 mL)
3. washwashed with water (2×50 mL) and brine (50 mL) solution
4. dry with materialThe combined organic layers were dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customto give crude product which
8. customwas purified by column chromatography (Silica gel 20% EtOAc in hexane)