54258-41-2

4199-88-6

54258-41-2

4) Add 0.64 g (6.0 mmol) of 10% palladium-carbon catalyst, 4.85 g of 80% (mass fraction) hydrazine hydrate, and 20.0 mL of anhydrous ethanol to a 250 mL three-neck flask. A reflux condenser was installed and the two remaining ports were sealed with glass stoppers. The device was placed on a DF-101S heated thermostatic magnetic stirrer with the oil bath temperature set to 72 °C and stirring was initiated. Subsequently, 2.03 g (9 mmol) of 5-nitro-1,10-phenanthroline was added to the flask, followed by 40 mL of anhydrous ethanol to ensure complete dissolution (total ethanol volume of 60 mL). The dissolved 5-nitro-1,10-phenanthroline solution was quickly poured into a three-necked flask after the oil bath temperature reached 72 °C. After the reaction lasted for 10 hours, the heating was stopped and left for about 1 hour to ensure complete dissolution of 5-nitro-1,10-phenanthroline. The oil bath was again heated to 60°C. If any precipitate redissolved in the system, the three-necked flask was immediately removed, the solution was poured into a thermal filter, and the residue was washed with anhydrous ethanol about five times. The filtrate was collected and concentrated using a rotary evaporator to remove the solvent, yielding a yellow solid. The solid was dried in a vacuum oven at 60 °C for 12 hours. Finally, the product was recrystallized with anhydrous ethanol, filtered and dried under vacuum at 60 °C for 12 h to give 1.28 g of yellow-brown solid powder, 5-amino-1,10-phenanthroline (Phen-NH2), in 72.9% yield.