Microwave-Assisted Acetylation of Alcohols Using Acidic Ethyl Acetate in Five Minutes

Introduction: Microwave-assisted organic synthesis is increasingly sought as a strategy to accelerate organic synthesis while minimizing waste. This study aimed to develop a rapid, scal-able, and environmentally friendly protocol for acetylating both primary and secondary alcohols using ethyl acetate as both a solvent and an acetylating agent. Methods: Reactions were performed in a microwave reactor (300 W, 120 °C, 5 min) with p-tol-uenesulfonic acid (p-TSA, 0.1 – 0.2 equiv.) as a catalyst. Twenty-six representative alcohols (twenty-one primary and five secondary) were examined under optimized conditions. The conver-sions were quantified and confirmed using ¹H NMR spectroscopy, and ethanol generated in situ was identified as the sole by-product. Results: Acetylation of primary alcohols yielded conversions of 67–94%, while secondary alcohols showed 78–91% conversion. The reaction time was 5 minutes. Discussion: This protocol surpasses existing methods in both speed and atom economy, with ethyl acetate serving a dual role that obviates the use of halogenated solvents and acetic anhydride. How-ever, tertiary alcohols exhibited no to minimal conversion under these acetylation conditions. Conclusion: Microwave-accelerated, p-TSA-catalyzed acetylation using ethyl acetate affords high yields within five minutes and generates minimal waste. The method presents a practical and sus-tainable alternative for the synthesis of acetate esters in both academic and industrial settings.