Both hexachlorobenzene and hexabromobenzene were successfully hydrodehalogenated to the monohalogenated derivative and ultimately to benzene (which was subsequently reduced to cyclohexane) using a mixture of metallic Ca, ethanol, and Rh/C, by simple stirring in diethyl ether, at room or mild temperature (60 °C). Various experiments were performed in order to assess the role of the solvent and Rh/C catalyst, as well as for elucidating the reaction pathway.
Keywords: Ethanol; Hexabromobenzene; Hexachlorobenzene; Hydrodehalogenation; Metallic Ca; Rh/C.