| abstract |
A preparation method of caprolactam relates to a method for preparing caprolactam from cyclohexanone oxime in a Lewis acidic eutectic solvent system, and is characterized in that a Lewis acidic eutectic solvent is adopted as a reaction medium, the molar ratio of the cyclohexanone oxime to the Lewis acidic eutectic solvent is 50: 1-1: 50, the reaction is carried out for 1-10 hours at the reaction temperature of 60-180 ℃, the caprolactam is prepared, and the Lewis acidic eutectic solvent is recycled. The invention is characterized in that: the used eutectic solvent has the double functions of reaction medium and catalyst, the cyclohexanone oxime can be automatically rearranged in the system without additional catalyst, the yield of the obtained caprolactam is more than 99.1 percent, and the purity can reach 99.5 percent. The Lewis acid eutectic solvent can be repeatedly used and is easy to separate products. The preparation process is simple and convenient, the reaction condition is mild, and the used eutectic solvent raw material is cheap and easy to obtain and has low corrosivity. |