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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 4Å 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 4Å 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.

The ability of commercial immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) to catalyze the acetylation of essential clove oil with acetic anhydride in a solvent-free system was studied, and the antimicrobial activity of the ester formed was evaluated as well. Experimental design based on two variables (eugenol to acetic anhydride molar ratio and temperature) was employed to evaluate the experimental conditions of eugenyl acetate ester production. The maximum conversion yield (92.86 %) was obtained using Lipozyme TL IM (5 wt%, based on the total amount of substrates), with eugenol to acetic anhydride molar ratio of 1:5 at 70 °C. The chemical structure of the eugenyl acetate ester obtained at the optimized condition, and purified, was confirmed by the proton nuclear magnetic resonance ((1)H-NMR) analysis. The antimicrobial activity of eugenyl acetate ester was proven effective on Gram-positive and Gram-negative bacteria, with means of 16.62 and 17.55 mm of inhibition halo.

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