ABSTRACT
This chapter discusses the most important reactions known to occur with chlorobiphenyls. Mono-, di-, and trichlorobiphenyls can be oxidized to the corresponding chlorobenzoic acids with chromic anhydride and acetic acid. Replacement of chlorine in chlorobiphenyls by hydrogen via chemical reaction has been described for decachlorobiphenyl using lithium aluminum hydride, butyl lithium and water, or the Grignard reagent and water. All chlorobiphenyls undergo complete chlorination to decachlorobiphenyl when treated with antimony pentachloride antimony pentachloride-iodine or reagent BMC or trichlorosulfur tetrachloroaluminate. Nitration of chlorobiphenyls is one of the few reactions which gives well defined derivatives in good yield even of highly chlorinated members of the series. Nucleophilic displacement in chlorobiphenyls has mainly been studied with decachlorobiphenyl. Nucleophilic displacement of chlorine by alkoxy groups employing sodium alkoxides or alkali and alcohol at high temperatures and pressures is a patented process for the preparation of alkoxy and dialkoxypoly-chlorobiphenyls.
