Synthesis of 2‐Ethyl Anthraquinone From 2‐Ethyl Benzoyl Benzoic Acid by Using Beta Zeolite Catalyst and Kinetic Studies

Abstract The catalytic dehydration of 2‐ethyl benzoyl benzoic acid (E‐BBA) to 2‐ethyl anthraquinone (2‐EAQ) was systematically investigated using Beta zeolite as a heterogeneous catalyst in a solvent‐assisted system. The reaction conducted at 250 °C under atmospheric pressure using diethyl phthalate as solvent achieved a maximum conversion of 100% and an isolated yield of 82%. This study demonstrates a green and scalable alternative to conventional oleum‐based methods, significantly reducing acid waste and process hazards. Catalyst characterization (XRD, SEM‐EDX, BET, NH 3 ‐TPD) revealed excellent structural stability and retention of acidity, with reusability confirmed over three cycles without significant loss in activity, critical for industrial viability. The use of a high‐boiling, nonaqueous solvent provided operational simplicity while minimizing side reactions and thermal degradation. Furthermore, a detailed kinetic investigation employing the Langmuir–Hinshelwood–Hougen–Watson (LHHW) model provided insight into surface reaction mechanisms and adsorption behavior specific to this substrate, catalyst, and solvent system. The model accurately fit experimental data and yielded an activation energy of 64.28 kJ/mol. While the LHHW model is well established, its first application to this reaction system under solvent‐assisted conditions provides new quantitative insight in the role Beta zeolite in the 2‐EAQ synthesis. These findings highlight the potential of Beta zeolite as a reusable, efficient, and environmentally benign catalyst for industrial scale anthraquinone production.