Synthesis of dioxin-like monofluorinated PCBs: for the use as internal standards for PCB analysis

Monofluorinated polychlorinated biphenyls (fluoro-PCBs) have been prepared using the Suzuki-coupling, for use as analytical standards for PCB measurements. Seven of these fluoro-PCBs are analogues of the dioxin-like PCBs, listed by the WHO as the most toxic PCB congeners. Four highly chlorinated fluoro-PCBs have been prepared by Suzuki-coupling of 2,3,5,6-tetrachloro-bromoaniline with various substituted arylboronic acids. The resulting amino-fluoro-PCBs are chlorinated using the Sandmeyer reaction or deaminated to yield tetra-, penta- and hexa-chlorinated fluoro-PCBs. The fluoro-PCBs elute just before the corresponding PCBs in the GC chromatogram, which strongly indicates their potential as analytical standards.