Efficient synthesis of tricaproin: catalyst and reaction optimization

Abstract

This study presents a short communication on exploring, for the first time, a simple approach for the selective and highly effective synthesis of tricaproin by synergistically combining silicon tripolyphosphate and phosphoric acid in the catalytic esterification of glycerol with caproic acid. Results reveal that within the initial hour of the synthesis, the conversion in the presence of the proposed mixture achieved an efficiency of 62.99 %, whereas this figure for individual catalysts only modestly stopped at 27.50 and 11.74 %, respectively. Furthermore, the inherent shortcomings in the tricaprion synthesis, such as catalyst deactivation, resinification of the reaction solution, and generation of numerous by-products, were successfully addressed. The structure of the resultant tricaproin and the possible absence of undesired by-products were confirmed by NMR, mass spectrometry, FT-IR, and TLC. The optimal conditions for the synthesis were also investigated. The study not only contributes a practical and selective synthetic approach for tricaproin but also paves the way for exploring novel avenues to enhance the efficiency of the catalytic esterification.