Preparation and NMR Spectroscopy of Selected Polychlorinated meta‐Terphenyls

Abstract The preparation of eight polychlorinated terphenyl (PCT) congeners by Suzuki coupling from readily available starting materials is described: the dichloride 3,3′′‐dichloro‐meta‐terphenyl (3), the tetrachlorides 2,2′′3,3′′‐tetrachloro‐meta‐terphenyl (5a), 2,2′′4,4′′‐tetrachloro‐meta‐terphenyl (5b), 2,2′′,5,5′′‐tetrachloro‐meta‐terphenyl (5c), and 3,3′′,4,4′′‐tetrachloro‐meta‐terphenyl (5d) and the pentachlorides 3,4,5′,3′′,4′′‐pentachloro‐meta‐terphenyl (8), 2,4,5′,3′′,4′′‐pentachloro‐meta‐terphenyl (9), and 2,4,5′,3′′,5′′‐pentachloro‐meta‐terphenyl (10), the latter being obtained by a combinatorial approach to these meta‐terphenyl derivatives. The structure elucidation of these model compounds rests largely on NMR spectroscopy which allows unambiguous assignment of the substitution pattern.