反应详情

Methyl-4-bromo-3-hydroxy-2-thiophenecarboxylate (20 g, 84.36 mmol) was dissolved in 400 mL of acetone. Potassium carbonate (58 g, 420.3 mmol) was added followed by iodomethane (45 mL, 424 mmol). The resulting mixture was heated at reflux for 4.5 h. After cooling, the mixture was filtered through a thin Celite pad, rinsing with methylene chloride. The filtrate was concentrated in vacuo to give 22.5 g to of methyl-4-bromo-3-methoxy-2-thiophenecarboxylate (crude, 100%, MH+=251.0) as a dark green solid.

1. temperatureThe resulting mixture was heated
2. temperatureat reflux for 4.5 h
3. temperatureAfter cooling
4. filtrationthe mixture was filtered through a thin Celite pad
5. washrinsing with methylene chloride
6. concentrationThe filtrate was concentrated in vacuo