反应详情

To a solution of methyl 4-methylthiophene-2-carboxylate (2.7 g, 6.4 mmol) in dichloromethane (20 mL) is added 48% aq. HBr (12 mL), H2SO4 (6 mL), ZnBr2 (5.4 g), and HCHO (2.2 mL, 37%) at 0-5° C. The mixture is stirred at room temperature for 16 hours. The solution is diluted with water, extracted with dichloromethane, washed with NaHCO3 solution, saturated brine solution, water, dried over sodium sulfate, and concentrated to give the title compound as an off white solid (3.5 g, 81%).

1. extractionextracted with dichloromethane
2. washwashed with NaHCO3 solution, saturated brine solution, water
3. dry with materialdried over sodium sulfate
4. concentrationconcentrated