14346-13-5

17420-30-3

14346-13-5

Step 1: 3 kg of 2-cyano-4-nitroaniline, 15 liters of ethanol, 80 g of 3% Pt/C catalyst and 300 ml of ammonia (chemically pure) were added to a 20 liter autoclave. After replacing the air in the kettle with nitrogen, hydrogen was introduced, the temperature was raised to 50°C, and the pressure was maintained at 1.6 MPa until the reaction no longer absorbed hydrogen. After the reaction was completed, the reaction mixture was filtered and the filtrate was collected. Step 2: The filtrate obtained from Step 1 was allowed to crystallize at -10°C for 18 hours to form a solid-liquid mixture. Step 3: Solid-liquid separation of the solid-liquid mixture of Step 2 was carried out under nitrogen protection to obtain solids and filtrate. The solid was dried in a vacuum drying oven and further dried by vacuum distillation at 130°C~136°C to obtain white 2,5-diaminobenzonitrile. Step 4: The filtrate collected in Step 3 was concentrated under vacuum to 1/5 of the original volume at 45° C. The operation of Steps 2 and 3 was repeated to reduce the concentrated filtrate, and the resulting 2,5-diaminobenzonitrile was finally combined with the product of Step 3 to obtain a total of 2.4 kg of 2,5-diaminobenzonitrile. The 2,5-diaminobenzonitrile prepared in this embodiment had a mass purity of not less than 99.5% and a yield of 98.0%.