4-Biphenylyl Sulfate-d5 Potassium Salt is the isotope labelled analog of 4-Biphenylyl Sulfate Potassium Salt . 4-Biphenylyl Sulfate Potassium Salt is a derivative of 4-Phenylphenol (P336135). 4-Phenylphenol is a reagent used in the synthesis of pyrrolo[1,2-c]imidazole dione derivatives as selective serotonin 5-HT1A receptor agonists with antinociceptive activity.