Synthesis of Eugenyl Acetate in Solvent-Free Acetylation: Process Optimization and Kinetic Evaluation

Abstract

In this work, the synthesis of eugenyl acetate was evaluated in the presence of heterogeneous catalysts aiming developing an economical and environmentally friendly process. The catalysts used were molecular sieve 4A and Amberlite XAD-16, and highest conversions were obtained in the investigated conditions by experimental design for both catalysts. In the kinetic study the effects of temperature, catalyst concentration and eugenol to acetic anhydride molar ratio in the conversion process were evaluated. The kinetics using molecular sieves 4A were performed until 6 h of reaction, reaching conversions above 90% in 2 h and the activation energy was 2.40 kcal.mol-1. With Amberlite XAD-16 up to 2 h reactions were conducted and in just 3 min high reaction conversions (97.8%) were achieved with lower activation energy (1.73 kcal mol-1) than the molecular sieve, demonstrating that both catalysts are effective for producing the eugenyl acetate. Heterogeneous catalysts allowed reaching high conversions using less amounts of substrates, in a solvent-free system, and also making possible regeneration and reuse.