Weighed 1.04g of trans-1,2-cyclohexanediamine sulfate product and 2.31g of chloroacetic acid, dissolved in 2.5mL of distilled water. Under the condition of room temperature, add NaOH aqueous solution (5.0mL, 30%) dropwise while stirring, after the dropwise addition, slowly raise the temperature to 70 , keep warm for 2h, then slowly lower the temperature to 50 , control the reaction solution pH=12, keep warm and react for 1h. stop the reaction, cool and let it stand, filter it, dropwise add hydrochloric acid solution (6 mol/L) to the filtrate until the pH=1, stop dropping and continue stirring. 20min, filtration, washing, the resulting product was dried at 105 to obtain trans-1,2-cyclohexanediaminetetraacetic acid crude finished product.
