4091-48-9

Upstream product

• 4024-80-0 2,3,5,6-Tetrachlor-4,4-dibrom-cyclohexadien-(2,5)-on-⁽¹⁾ 
• 935-95-5 2,3,5,6-tetrachlorophenol 
• 5134-79-2 4-Diazo-2,3,5,6-tetrachlorocyclohexa-2,5-diene-1-one 

Downstream Products

• 99980-09-3 4-bromo-2,3,5,6,6-pentachloro-cyclohexa-2,4-dienone 
• 100130-96-9 benzenesulfonic acid-(4-bromo-2,3,5,6-tetrachloro-phenyl ester) 

Relevant academic research and scientific papers

Organochlorine compounds in pine needles: Methods and trends

During April 1989, needles from Scotch pine (Pinus sylvestris) trees were collected from a network of stations in West Germany, Denmark, Norway, and Sweden. Samples from selected stations were analyzed for hexachlorobenzene (HCB), pentachlorophenol (PCP), hexachlorocyclohexane isomers (α-HCH and γ- HCH [lindane]), DDT, and DDE. Accumulation of the investigated compounds was observed in up to four needle-year classes. γ-HCH decreased from south to north; the pattern for α-HCH was uniform; DDT/DDE also decreased from south to north. HCB was uniform throughout the sample area, and PCP was high in northern Sweden. Interpretation of trends was not altered by expressing concentrations on a fresh- or dry-weight basis or on a surface-area basis. The range of concentration variation for equivalent samples was 2 to 49% relative standard deviation; averages were 20 to 23%. There were no differences among trees facing the same open direction; among different directions, trees open to the south collected more DDT, but this was not the case with other substances. There were no differences between trees of different ages. Samples at 4 to 5 m had lower contaminant levels than from 1.5 m.

Identification of hydroxylated PCB metabolites and other phenolic halogenated pollutants in human blood plasma

A growing number of studies have reported phenolic halogenated compounds (PHCs) that are retained in the blood of humans and wildlife. These PHCs may be industrial chemicals; metabolites thereof, as in the case with polychlorobiphenylols (OH-PCBs); or of natural origin. The present study was aimed to identify hitherto unknown PHCs in human plasma with chemical structures that are consistent to PHCs known to possess endocrine-disrupting activity. For this purpose, samples of blood plasma from 10 randomly selected male blood donors from Sweden were pooled and analyzed by GC/ECD and GC/MS. Brominated, bromochlorinated, and chlorinated methyl derivatives of phenols and OH-PCBs were synthesized to be used as authentic reference standards. More than 100 PHCs were indicated in the plasma, and among those a total of 9 monocyclic brominated or chlorinated phenol-, guaiacol-, and/or catechol-type compounds were identified as their methylated derivatives. The two major compounds were 2,4,6-tribromophenol and pentachlorophenol. Thirty-eight OH-PCB congeners were structurally identified on two GC columns of different polarity. The origin of the OH-PCB metabolites in the context of their parent PCB congeners are suggested. Other PHCs identified in the male plasma were Triclosan (5-chloro-2-[2,4-dichlorophenoxy] phenol), a common bactericide; 4-hydroxy-heptachlorostyrene, a metabolite of octachlorostyrene; and 3,5-dibromo-2-(2,4-dibromophenoxy)phenol, a natural compound and a potential metabolite of polybrominated diphenyl ethers.