Synthesis and Toxicity of Halogenated Bisphenol Monosubstituted‐Ethers: Establishing a Library for Potential Environmental Transformation Products of Emerging Contaminant

Abstract As an important branch of halogenated bisphenol compounds, the halogenated bisphenol monosubstituted‐ether compounds have received a lot of attention in environmental health science because of their toxicity and variability. In this study, a synthetic method for bisphenol monosubstituted‐ether byproduct libraries was developed. By using the versatile and efficient method, tetrachlorobisphenol A, tetrabromobisphenol A, and tetrabromobisphenol S monosubstituted alkyl‐ether compounds were accessed in 39–82 % yield. Subsequently, the cytotoxicity of 27 compounds were screened using three different cell lines (HepG2, mouse primary astrocytes and Chang liver cells). Compound 2,6‐dibromo‐4‐[3,5‐dibromo‐4‐(2‐hydroxyethoxy)benzene‐1‐sulfonyl]phenol was more toxic than other compounds in various cells, and the sensitivity of this compound to the normal hepatocytes and cancer cells was inconsistent. The compounds 2,6‐dichloro‐4‐(2‐{3,5‐dichloro‐4‐[(prop‐2‐en‐1‐yl)oxy]phenyl}propan‐2‐yl)phenol and 2,6‐dibromo‐4‐(2‐{3,5‐dibromo‐4‐[(prop‐2‐en‐1‐yl)oxy]phenyl}propan‐2‐yl)phenol were the most toxic to HepG2 cells, and most of the other compounds inhibited cell proliferation. Moreover, typical compounds were also reproductive and developmental toxic to zebrafish embryos at different concentrations. The synthetic byproduct libraries could be used as pure standard compounds and applied in research on environmental behavior and the transformation of halogenated flame retardants.