反应详情

To a solution of 500 g of 3,4-dimethoxybenzaldehyde in 2.5 L of methanol was added dropwise 529 g of bromine at room temperature (under cooling, if necessary) over 1 hour, and the mixture was stirred at the same temperature for 3 hours. To the reaction solution was added dropwise 2.5 L of water, and the crystals were precipitated. To the crystal suspension was added 20% aqueous sodium hydroxide solution at room temperature to adjust it to pH about 9 to 10, and then cooled. The precipitated crystals were collected by filtration and washed with water, and then dried at 50° C. for 12 hours to give 718.78 g of 6-bromo-3,4-dimethoxybenzaldehyde (yield: 98%).

1. temperature(under cooling, if necessary) over 1 hour
2. customthe crystals were precipitated
3. additionTo the crystal suspension was added 20% aqueous sodium hydroxide solution at room temperature
4. temperaturecooled
5. filtrationThe precipitated crystals were collected by filtration
6. washwashed with water
7. customdried at 50° C. for 12 hours