Test purchase, synthesis and characterization of 3-fluorophenmetrazine (3-FPM) and differentiation from its ortho- and para-substituted isomers

Abstract

The knowledge captured in patent and scientific research literature stimulates new ideas and fosters new drug development efforts. Manufacturers and entrepreneurs dedicated to the sale of ‘research chemicals’ and/or new psychoactive substances (NPS) also make use of the access of information to identify, prepare and launch a range of new substances. One of the most recent compounds to appear on the NPS market was the phenmetrazine analog 3-fluorophenmetrazine (3-FPM) that represented one of many phenylmorpholines designed to explore treatment options in areas such as obesity and drug dependence. The anorectic drug analogs phenmetrazine and phendimetrazine, used as prescription medicines before they were withdrawn, feature amphetamine-like properties associated with monoamine release and available data on 3-FPM suggest that the effects might show mechanistic overlaps. This study describes the synthesis and extensive analytical characterization of 3-FPM and its differentiation from synthesized ortho- and para- substituted isomers, 2-FPM and 4-FPM, respectively. This study was triggered by the purchase of five powdered samples advertised as 3-FPM by five different Internet vendors based in the United Kingdom. The analytical data obtained for the vendor samples were consistent with the synthesized 3-FPM standard and differentiation between all three isomers was possible. The presence of positional isomers and the absence of suitable reference material can cause difficulties in the day-to-day operation of forensic work and given the rate at which many of the newly emerging NPS appear on the market, a comprehensive approach is needed when attempting to decipher the identity of NPS arriving onto the drug market.