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.

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► 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.