<p>The orange flavour, <i>n</i>-octyl acetate, was synthesized in the presence of ultrasound (US) over an H₅PW₁₀V₂O₄₀ /FAC catalyst. The effect of parameters such as temperature (A), alcohol to acid ratio (B), duty cycle (C) and ultrasound power (D) on the conversion was optimised using response surface methodology. Various experiments were designed as per the central composite design method using the design of expert software. The relation between operating variables and conversion was established by a quadratic mathematical model equation. The relation of independent variables and their effect on conversion was explained by executing the statistical analysis and analysis of variance. The optimum solution of the maximum conversion of 78.2% in 180 minutes was obtained in the presence of US horn at parameters viz temperature (373 K), mole ratio (<i>n</i>-octyl alcohol to acetic acid) (2), duty cycle (80%) and ultrasound power (100 W). The intensification by US horn was compared to conventional processes.</p> Graphical abstract <p>The <i>n</i>-octyl acetate was synthesized over an H₅PW₁₀V₂O₄₀/FAC catalyst in the presence of ultrasound irradiation. It has many applications in cosmetics, hair products, and skin locations. The synthesis of <i>n</i>-octyl acetate in the ultrasound process was compared with the conventional synthesis. There was a considerable reduction in reaction time in ultrasound-assisted synthesis.</p>