Synthesis, characterisation and quantification of the new psychoactive substance 1-(1,3-benzodioxol-5-yl)-2-(propylamino)butan-1-one (bk-PBDB, putylone)

Abstract

Synthetic cathinones are a continually evolving family of illicit drugs, with novel analogues frequently being detected. This paper reports the detection of 1-(1,3-benzodioxol-5-yl)-2-(propylamino)butan-1-one, bk-PBDB (putylone), within solid dosage forms (tablets) seized by law enforcement for the first time in the United Kingdom. The identity of the compound was confirmed via the synthesis of a pure bk-PBDB reference standard and direct spectral comparison by 1H NMR and GC-EI-MS analysis. A full analytical profiling of bk-PBDB by nuclear magnetic resonance (NMR), attenuated total reflection Fourier-transform infrared (FTIR) spectroscopy and gas chromatography-electron ionisation-mass spectrometry (GC-EI-MS) is reported and shows good concordance between the seized sample and the reference standard. A validated GC-EI-MS method for the routine quantification of the cathinone in bulk forensic samples (LOD: 0.09 μg/mL, LOQ: 0.26 μg/mL) was also developed and using this method, the seized tablets were determined to contain a mixture of bk-PBDB (130.6–135.5 mg/tablet) and caffeine (40.2–43.4 mg/tablet) respectively.