572-83-8

7321-27-9

In the preferred embodiment, 275.0 g of diethylene glycol dimethyl ether was added to a 500 mL three-necked flask, 68.0 g (0.51 mol) of aluminum chloride solids were slowly added, the temperature was controlled at 60°C, and the addition process took about 20 min, and the system became grey or milky white and cloudy. Cool to 30 °C and set aside. To another 1 L three-necked flask was added 49.2 g (0.17 mol) of 2-bromoanthracene-9,10-dione, 200.0 g of diethylene glycol dimethyl ether, and 27.5 g (0.51 mol) of potassium with stirring. Subsequently, borohydride was added and the system was changed to a yellow-green turbid solution, which was heated to 105 °C and maintained for 30 min. During heating, the system was changed from a yellow-green turbid solution to a pink turbid solution and finally to a brown turbid solution. After the reaction was completed, the above aluminum chloride solution was slowly added to the system, and the internal temperature was controlled to be between 90 and 110 °C. In the exothermic reaction of the first 1/3 stage of the drop, the second 2/3 stage of the heat-absorbing reaction, drop during the process of gas bubbles, the system from the brown turbid liquid to bright yellow turbid liquid, and ultimately become a yellow turbid liquid. The dosing process took about 20 min, and the system was quickly cooled down to 40°C in a water bath after the dosing was completed. The system was poured into a mixture of concentrated hydrochloric acid, water and ethanol (100 g/400 g/300 g), accompanied by the generation of large amounts of gas. The temperature was controlled to be below 60°C during the hydrolysis. After completion of hydrolysis, it was cooled to 25 °C, filtered, and the filter cake was washed with 100.0 g of water and 100.0 g of anhydrous ethanol to obtain a yellow filter cake, which is the crude product. Mix the crude product with anhydrous ethanol in the ratio of 1:10, heat to 50~60°C, stirring for 1.0 h, cool to 25~30°C, keep warm for 0.5 h, extract and filter, wash the filter cake with a small amount of anhydrous ethanol to get a white solid, which is the pure product. After drying (50 °C, 200 Pa, 5 h), 35.8 g of white powdery solid was obtained with 82.02% yield.