1,4-Dibromo-2,5-dimethoxybenzene

150-78-7

2674-34-2

Example 2: Preparation of 2,5-dibromo-1,4-dimethoxybenzene (2); In a 1 liter round-bottomed flask, a solution of chloroform (50 mL) of bromine (35.2 g, 220 mmol) was added slowly and dropwise to a solution of chloroform (400 mL) of 1,4-dimethoxybenzene (13.8 g, 100 mmol). The reaction mixture was stirred at room temperature for 3 hours before 100 mL of saturated Na2CO3 solution was added to quench the reaction. The organic layer was separated, washed sequentially with water and saturated brine, and dried over anhydrous sodium sulfate. The solvent was removed by concentration under reduced pressure and the resulting residue was recrystallized from ethanol to give pure 2,5-dibromo-1,4-dimethoxybenzene (25.8 g, 85% yield). The product was characterized by 1H NMR (CDCl3): δ 7.128 (s, 2H), 3.873 (s, 6H).