The traditional production of long‐chain organic esters like isobutyl isobutyrate (BIBE) suffers from severe problems due to the homogenous catalyst in process and complex system thermodynamics. In this work, an innovative bifunctional deep eutectic solvent (DES) is introduced, playing as both reaction catalyst and extraction solvent, to intensify the esterification process. The DES was formed by imidazole (Im) and p‐toluenesulfonic acid (PTSA), which was for the first time found acid–base tunable, represented by weak basic DES [3Im:PTSA] and strong acidic DES [Im:2PTSA]. The formation mechanisms of [3Im:PTSA] and [Im:2PTSA] were illustrated by Fourier‐transform infrared spectroscopy (FTIR) and COnductor‐like Screening MOdel for Real Solvent (COSMO‐RS) combined with the Im‐PTSA phase diagram. The dual functions of the acidic [Im:2PTSA] in reactive extraction were evaluated by σ‐potential analysis and esterification experiments. The high conversion, easy product separation, and good solvent reusability confirm the excellent catalytic and solvent effect of [Im:2PTSA]. © 2018 American Institute of Chemical Engineers AIChE J, 65: 675–683, 2019

中文翻译：

---

双功能咪唑-PTSA深共熔溶剂，用于反应萃取中长链酯IBIBE的合成

长链有机酯（如异丁酸异丁酯（BIBE））的传统生产由于工艺中均相催化剂和复杂的系统热力学而面临严重问题。在这项工作中，引入了一种创新的双功能深共熔溶剂（DES），既起着反应催化剂的作用，又起着萃取溶剂的作用，以增强酯化过程。DES由咪唑（Im）和p甲苯磺酸（PTSA），首次发现酸碱可调，以弱碱性DES [3Im：PTSA]和强酸性DES [Im：2PTSA]为代表。[3Im：PTSA]和[Im：2PTSA]的形成机理通过傅立叶变换红外光谱（FTIR）和类似真实导体的导体类似物筛选模型（COSMO-RS）结合Im-PTSA相图进行了说明。通过σ电位分析和酯化实验评估了酸性[Im：2PTSA]在反应萃取中的双重功能。高转化率，易于产品分离和良好的溶剂可重复使用性证实了[Im：2PTSA]的出色的催化和溶剂作用。©2018美国化学工程师学会AIChE J，65：675–683，2019