Transformation of Vanillin in Sub- and Supercritical Propanol-2 Media

Abstract The product formation sequence and kinetic regularities of vanillin transformations in the propanol-2 medium are investigated at different temperatures and durations of the process in a static mode. The vanillin transformation products are determined by the gas chromatography–mass spectrometry method. At a high degree of vanillin conversion (up to 100%), a relatively small number of compounds are formed, the main ones of which are substituted phenols and their derivatives, such as vanillyl alcohol and its isopropyl ether, guaiacol, creosol (2-methoxy-4-methylphenol), and homocatechol (3,4-dihydroxytoluene). A scheme of reciprocal transformations of intermediate compounds is proposed.