Response surface methodology based on the Box‐Behnken design for optimizing the synthesis of symmetrical anhydrides from acid chlorides using cerium (III) as a homogeneous catalyst

Abstract

Here we report the synthesis of symmetrical carboxylic acid anhydrides from acid chlorides using cerium (III) as a homogeneous catalyst. The optimal experimental conditions (temperature at 40 °C, catalyst loading at 30 mg, 1.5 equivalents of base, and solvent volume at 1 mL) for the preparation of benzoic anhydride 2 a were obtained using the Box‐Behnken design in combination with the response‐surface methodology. The analysis of variance showed that the presented quadratic model successfully performed the experimental data with coefficients of determination of R2=0.99. The predicted yield of synthesized anhydride 2 a obtained from the RSM under optimal conditions was 98.63 %. A confirmation test of the optimal conditions proved the viability of the model and gave a yield of 97.27 %. Under the optimal conditions, the resulting synthesized anhydrides 2 a–g were obtained with good isolated chemical yields of 60 %<yield<96 %.