反应详情

温度

75 °C

Methyl 3-hydroxy-4-[(trimethylsilyl)ethynyl]benzoate (4.15 g, 16.7 mmol) is dissolved in MeOH (45 ml) and treated with DIA (2.34 ml, 16.7 mmol). Copper iodide (159 mg, 0.84 mmol) is added portion-wise and the reaction is heated at 75° C. for 3 h. DARCO (2 g) is added and the reaction is stirred at 95° C. for an additional 2 h, then overnight at RT. The reaction is filtered, concentrated to a brown oil and the crude material is chromatographed over 300 g slurry-packed silica gel, eluting with 10% EtOAc/hexane. The appropriate fractions are collected and concentrated to afford 2.05 g (70%) of methyl 1-benzofuran-6-carboxylate as an orange crystalline solid. 1H NMR (400 MHz, CDCl3) δ 3.97, 6.84, 7.65, 7.78, 7.98, 8.22 ppm.

1. additiontreated with DIA (2.34 ml, 16.7 mmol)
2. customovernight
3. customat RT
4. filtrationThe reaction is filtered
5. concentrationconcentrated to a brown oil
6. customthe crude material is chromatographed over 300 g slurry-packed silica gel
7. washeluting with 10% EtOAc/hexane
8. customThe appropriate fractions are collected
9. concentrationconcentrated