Transformations of acetophenone and its derivatives in supercritical fluid isopropanol/CO2 in a continuous flow reactor in the presence of alumina

Acetophenone and its derivatives undergo various transformations in binary supercritical solvent isopropanol/CO2 in a flow reactor in the presence of granulated Al2O3. Depending on the reaction temperature, respective secondary alcohols, or isopropyl ethers, or substituted styrenes are formed at contact times of ∼4 min. Selectivity for the reaction products attains 96% at high conversion of initial compounds. It was shown that the nature of a substituent in ketone aromatic ring exerts primary effect both on the conversion of initial compounds and on stability of intermediates under reaction conditions, and thus affects the end product distribution.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Acetophenone and its derivatives can be transformed into alcohols or styrenes. ► The reactions proceed in a continuous flow reactor in a complex supercritical fluid. ► The products are formed with high selectivity at contact time about 4 min. ► Inexpensive alumina is used as a catalyst and isopropanol as a reducer.