The preparation of Ethylene glycol diphenyl ether is as follows:A three-necked flask was charged with 15.7 g of bromobenzene (100 mmol) and 47 ml of DMF, and stirred. 12.7 g of sodium carbonate (120 mmol, 1.2 eq.), 1.9 g of cuprous iodide (10 mmol, 0.1 eq.), 1.87 g of 2,2'-bipyridine (12 mmol, 0.1 eq.) and 7.4 g of ethylene glycol (120 mmol, 1.2 equivalent), the reaction mixture was stirred at 100 ° C overnight. After recovering DMF under reduced pressure, 100 ml of water and 100 ml of toluene were added, and the aqueous phase was extracted three times with 300 ml of toluene, and the organic layers were combined. Washed sequentially with 5% sodium carbonate. The organic phase was dried over anhydrous sodium sulfate, filtered, and then filtered and evaporated,The crude product was recrystallized from isopropanol and dried in vacuo to give 19.5 g of product, yield 91%, purity over 99%.