反应详情

A 25-mL single-neck round-bottomed flask equipped with a magnetic stirrer and reflux condenser was charged with 4 (160 mg, 0.73 mmol), 11 (304 mg, 0.66 mmol), cesium carbonate (475 mg, 1.46 mmol) and 1,4-dioxane (10 mL). After bubbling nitrogen through the resulting solution for 30 minutes, Xantphos (32 mg, 0.056 mmol) and tris(dibenzylideneacetone)dipalladium(0) (30 mg, 0.033 mmol) were added and the reaction mixture was heated at reflux for 16 h. After this time the reaction was cooled to room temperature and concentrated under reduced pressure. The resulting residue was absorbed onto silica gel and purified by flash chromatography to give a residue, which was further purified by preparative reverse phase HPLC to afford a 30% yield (143 mg) of 12 as a yellow solid: mp 155-156° C.; 1H NMR (500 MHz, DMSO-d6) δ 9.82 (s, 1H), 9.43 (s, 1H), 8.08 (d, 2H, J=7.5 Hz), 7.68 (s, 1H), 7.32 (d, 2H, J=7.5 Hz), 7.27-7.32 (m, 3H), 7.24 (s, 1H), 4.88 (bs, 1H), 3.42-3.75 (m, 4H), 3.59 (s, 3H), 2.95 (s, 3H), 2.76 (m, 2H), 2.61 (m, 5H), 2.28 (s, 3H), 1.78 (m, 4H); MS (ESI+) m/z 597 (M+H).

1. customA 25-mL single-neck round-bottomed flask equipped with a magnetic stirrer
2. temperaturereflux condenser
3. customAfter bubbling nitrogen through the resulting solution for 30 minutes
4. temperaturethe reaction mixture was heated
5. temperatureat reflux for 16 h
6. concentrationconcentrated under reduced pressure
7. customThe resulting residue was absorbed onto silica gel
8. custompurified by flash chromatography
9. customto give a residue, which
10. customwas further purified by preparative reverse phase HPLC