Chasing the Elusive Benzofuran Impurity of the THR Antagonist NH-3: Synthesis, Isotope Labeling, and Biological Activity

Latika Singh, Brandon Pressly, Brenda J. Mengeling, James C. Fettinger, John Furlow, Pamela J Lein, Heike Wulff, Vikrant Singh

Research output: Contribution to journalArticle

9 Scopus citations


We have synthesized and established the structure of a long-suspected, but hitherto unknown, benzofuran side product (EBI) formed during the synthesis of NH-3. Understanding the mechanism of its formation has enabled isotope (D) labeling. We further developed a highly efficient method for separating EBI from NH-3. Interestingly, EBI was found to be a very potent thyroid hormone receptor (THR) agonist, while NH-3 is an antagonist. In this process, we have also achieved a significantly improved synthesis of NH-3.

Original languageEnglish (US)
Pages (from-to)1870-1876
Number of pages7
JournalJournal of Organic Chemistry
Issue number5
StatePublished - Mar 4 2016


ASJC Scopus subject areas

  • Organic Chemistry

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