Journal of Supercritical Fluids, Vol.140, 233-237, 2018
Highly selective reduction of nitroarenes by sc-isopropanol in the presence of zirconia in a flow reactor
Reduction of nitroarenes using supercritical isopropanol as a source of hydrogen was studied in a flow reactor in the presence of zirconia at temperatures of 515 - 630 K and with residence time about 10 min. Zirconia was shown for the first time to be an effective and selective catalyst for transfer hydrogenation of nitroarenes. The use of complex supercritical fluid IPrOH/CO2 provided 100% selectivity for aniline at 95% conversion of nitrobenzene. In the absence of CO2, the selectivity was reduced due to formation of alkoxylation and N-alkylation by-products. The system can also be used for highly selective reduction of bromonitrobenzene avoiding undesired hydrodehalogenation.