Preparation method of benzidine_Kain Industrial Additive

Background and overview[1] Toluidine can be used as a pharmaceutical synthesis intermediate. Preparation[1] The specific steps for the preparation of benzidine are as follows: In a 500ml four-neck flask equipped with a thermometer, reflux condenser and stirrer, add 350g 30 mass% fuming sulfuric acid (1.31molSO3), and keep the internal temperature at 30°C to 40 ℃.…