A Comparative Study on the Thermal and Microwave-assisted Direct Esterification of Phenyl-H-phosphinic Acid - Modeling the Rate Enhancing Effect of MWs

Background: The theoretical background of MW-assisted reactions is in the focus these days. Objective and Method: We wished to model the distribution of local overheatings (OHs) mathematically, and the rate enhancing effect of the OHs utilizing the Arrhenius equation. The model reaction was the esterification of phenyl-H-phosphinic acid with 15-fold butanol at 160 °C. Results: The results of the modelling and predictions matched the experimental data revealing the MWassited esterification to be 2.71 time faster than the thermal reaction. Conclusion: Our explanation for the beneficial effect of MW irradiation assuming local OHs may be modelled well, and is in accord with experimental data.