The syntheses and characterization 3β-(4-fluorobenzoyloxy)tropane (fluorotropacocaine) and its 3α isomer.

3β-(4-Fluorobenzoyloxy)tropane (3β-FBT, fluorotropacocaine) was first reported by Finnish authorities to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) via the Early Warning System (EWS) in 2008 and our own laboratory tentatively identified it in 2010 in several products purchased from head shops. Very little is known about this cocaine-like drug and, as no reference standards were available, we have synthesized and characterized both 3β-FBT and its 3α isomer for use as reference standards. The two compounds are separable by gas chromatography (GC) but their electron-impact (EI) mass spectra were found to be almost identical. ¹⁹F NMR spectroscopy was also found to be a useful technique for distinguishing the two isomers.