9,9-Bis(4-aminophenyl)fluorene

486-25-9

62-53-3

15499-84-0

General procedure for the synthesis of 9,9-bis(4-aminophenyl)fluorene from 9-fluorenone and aniline: 72 g of 9-fluorenone, 155.4 g of aniline hydrochloride, 10 g of sodium bisulfite and 72 g of 9-fluorenone were added to a reaction unit equipped with a water separator. Under stirring, 145 g of aniline and 100 g of toluene were heated to 125-130 °C and reacted at that temperature for 3 hours while the water generated was removed through the water separator. Subsequently, the temperature was slowly increased to 145-150 °C and maintained for 3 hours. Upon completion of the reaction, it was cooled to 95°C. At this temperature, a 10% sodium hydroxide solution was added dropwise until the pH of the reaction mixture was about 7. The neutralization reaction was carried out for 3 hours. Thermal stratification was carried out at 95°C to separate the aqueous layer and the upper oil layer was collected and transferred to a flask. The temperature of the mixture was gradually reduced to 20-30°C with stirring and stirred at this temperature for 1 hour to promote crystallization. After filtration, the mixture was dried to give about 185.6 g of crude product. 185.6 g of 9,9-bis(4-aminophenyl)fluorene and 300 g of xylene were added to the reactor and pulped at 30 °C and filtered to give 170 g of product in wet weight, which dried to 141 g. 141 g of 9,9-bis(4-aminophenyl)fluorene, 2800 g of deionized water, 49.3 g of 33% hydrochloric acid, and 28 g of activated charcoal were added to the flask and heated up to 65-70 °C , decolorized for 2 hours. The filtrate was hot-filtered at 70 °C and the filtrate was transferred to another flask, the pH was adjusted to 9-10 with 10% ammonia and stirred at 60-65 °C for 3 hours to ensure complete neutralization. After completion of neutralization, it was cooled to 20-30 °C, filtered and dried to give 130 g of product in 93.4% yield. The product was a pure white solid with a purity of 99.7%.