Unique bipiperidinyl impurities produced from the “One-Pot” synthesis of fentanyl

Abstract

The synthetic opioid fentanyl has consistently been on the illicit drug market within the United States for more than five years. One of the many challenges to law enforcement is determining the manner in which the fentanyl is being synthesized. Knowing the synthetic route being utilized in illicit production could allow law enforcement intelligence to track and control essential fentanyl precursors. Identifying the synthetic route during the analyses of illicit fentanyl requires knowledge of any and all possible synthetic impurities that may be formed. In 2005, researchers from India published a modified version of the Siegfried route that could reportedly be completed in one reaction vessel. The “one-pot” method was investigated, and three new synthetic impurities were subsequently identified and characterized. The formation of these synthetic impurities and their analytical characterization are discussed.