Obtained by bromination and chlorination of o-chlorophenol: dissolve o-chlorophenol in carbon tetrachloride, add bromine dropwise with stirring at below 30°C, continue stirring and react for 2h after addition, then remove hydrobromic acid at room temperature, recover carbon tetrachloride and distill under reduced pressure, collect the fraction of 110-120°C (2kPChemicalbooka), and obtain 4-bromo-2-chlorophenol. Dissolve 4-bromo-2-chlorophenol in acetic acid and pass chlorine gas under ice-cold conditions until no more crystals are precipitated. Heat and reflux until all crystals are dissolved, decolorized, filtered, cool and crystallized, filter, and wash with petroleum ether to obtain the finished product 4-Bromo-2,6-dichlorophenol.
