Synthesis of pentachlorophenol

Patent Granted PCP can be produced by the chlorination of phenol in the presence of catalyst (anhydrous aluminium or ferric chloride) and a temperature of up to approximately 191 °C. This process does not result in complete chlorination and commercial PCP is only 84-90% pure. The main contaminants include other polychlorinated phenols, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans. Some of these species are even more toxic than the PCP itself.