Preparation method for pentafluorophenol

The invention relates to a preparation method for pentafluorophenol. By taking hexafluorobenzene as an initial raw material, pentafluorophenol is prepared through etherification reaction and cracking reaction or by taking hexafluorobenzene as the initial raw material, pentafluorophenol is prepared by virtue of a one-step method. The preparation method provided by the invention does not need high temperature and pressurization, is less in energy consumption, and does not use expensive hydroiodic acid, so that the cost of the raw materials is low. Moreover, wastewater generated by etherification reaction is less, so that the preparation method is environmental-friendly; Cracking is carried out in a solvent, the material stirring effect is good, the reaction temperature is easy to control, and industrialization is easy to implement.