Continuous-flow synthesis of the liquid crystal intermediate 1-(4-ethoxy-2,3-difluorobenzyl)-4-propylcyclohexan-1-ol in a microfluidic system: Experimental and numerical studies

Abstract

• A tube-in-tube membrane-dispersion microreactor is designed for continuous synthesis. • The EDPO yield is increased by 10%, and the reaction time is shortened by 72.8%. • Coupling of DFT calculation and CFD simulation is proposed for predicting yield. A tube-in-tube membrane-dispersion microreactor is designed for the continuous synthesis of a liquid crystal intermediate without clogging. Under the optimal conditions, the intermediate exhibited a high yield of 78.1% at the residence time of 16.3 min. Compared with the conventional stirred-tank reactor, the reaction time is shortened by 72.8% and the yield is increased by 10% when the proposed microreactor is used. Moreover, the bath temperature can be increased from −60 °C to −40 °C, thereby significantly saving energy. Furthermore, a coupling method of density functional theory (DFT) calculation and computational fluid dynamics (CFD) simulation is proposed to analyze the flow field and predict the yields, which are found to be in good agreement with the experimental values. This study provides a practical approach for the efficient, high-yield, and continuous synthesis of liquid crystal intermediates and offers an in-depth understanding of these reactions and the establishment of process predictive models.