Highly efficient catalyzed by imidazolium-based dual-sulfonic acid functionalized ionic liquids for liquid phase Beckmann rearrangement: experiments and COSMO-RS calculations

• DOI: 10.1016/j.gce.2023.01.002
• Publication Date: 2023-01-12T07:38:03Z
• Authors: Xin Guo; Zhiyuan Wang; Ye Yang; Jiahui Zhang; Yanduo Liu; Zhiyuan Mu; Siqi Jiang; Chunxiao Ren; Dan Lv; Yufeng Hu; Zhichang Liu
• Keywords: Beckmann rearrangement; Cyclohexanone oxime; Caprolactam

A production technique with the high yield and environmentally friendly process need be developed for ε-Caprolactam (CPL) in chemical industry. This technology is highly desired to design synthesize high−performance catalysts liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) CPL. In this work, 3-methyl-1-(propyl-4-sulfonyl) imidazolium methanesulfonate ([PHSO3MIM][MSA]) efficient excellent synthesized successfully. When optimum molar ratio ZnCl2 over [PHSO3MIM][MSA] was 0.02, it exhibits selectivity (94%) CPL at 90 °C 1 h. Interestingly, Fourier-transform infrared (FT-IR) investigations show that functional Brønsted−Lewis acidic types ionic liquids (ILs) are formed by uniformly distributed [PHSO3MIM][MSA]. addition, hydrogen bond (H-bond) between CHO ILs. After ten reaction cycles, no significant structure changes observed recovered [PHSO3MIM][MSA]·ZnCl2. The solubilities ILs predicted using COSMO-RS model, results a promising candidate into Finally, theoretical model H-bond interactions further confirmed support advance mechanism. feasible way provided reaction.