反应详情

The product of Example 352A (292 mg, 0.744 mmol) and sodium carbonate (394 mg, 3.722 mmol) in anhydrous ethanol (12 mL) was heated to reflux under a nitrogen atmosphere for 6.5 hours. The reaction was cooled to room temperature, filtered, and the filtrate concentrated under reduced pressure. The residue was purified by column chromatography on silica gel eluting with 3% methanol/dichloromethane to give the title compound as a white solid (237 mg, 85%). MS (ESI−) m/z 373 (M−H)−. 1H NMR (300 MHz, DMSO-d6) δ 1.21 (t, J=6.99 Hz, 3 H) 3.67 (s, 2 H) 4.16 (q, J=6.99 Hz, 2 H) 5.20 (s, 2 H) 7.39 (m, 8 H) 12.21 (s, 1 H).

1. temperatureto reflux under a nitrogen atmosphere for 6.5 hours
2. filtrationfiltered
3. concentrationthe filtrate concentrated under reduced pressure
4. customThe residue was purified by column chromatography on silica gel eluting with 3% methanol/dichloromethane