Stable isotope characterisation of 3,4-methylenedioxyphenyl-2-propanone and 3,4-methylenedioxyamphetamine prepared from piperonal

Abstract

Rationale: Stable isotopic ratios can provide information for illicit drug profiling. The research presented here investigated the variations in stable isotopic ratios of hydrogen (δ² H), carbon (δ¹³ C), nitrogen (δ¹⁵ N) and oxygen (δ¹⁸ O) during the synthesis of MDP2P (3,4-methylenedioxyphenyl-2-propanone) and MDA (3,4-methylenedioxyamphetamine) prepared via the 'nitrostyrene' route.

Methods: Samples of MDA and MDP2P were synthesised from two isotopically characterised starting materials, piperonal and nitroethane. The isotopic compositions of the nitrostyrene intermediate (3,4-methylenedioxyphenyl-2-nitropropene, MDP2NP) and products MDP2P and MDA were also measured by isotope ratio mass spectrometry.

Results: A significantly negative change occurred to δ² H values during the production of MDP2NP, MDP2P and MDA, indicating a mechanism that favours inclusion or retention of ¹ H over ² H. This suggests that the δ² H compositions of MDA/MDP2P prepared from piperonal will not provide information on the synthetic history. Minimal changes were observed in δ¹³ C composition during the synthesis of MDP2NP, MDP2P and MDA, and minimal δ¹⁵ N compositional changes occurred in MDP2NP and MDA. Progressing from piperonal to MDP2NP, a minimal change occurred to δ¹⁸ O composition. A variable change to δ¹⁸ O was observed from MDP2NP with one sample becoming more positive in δ¹⁸ O composition and two samples becoming more negative. Progressing from MDP2NP to MDA, a significant negative change occurred to δ¹⁸ O composition.

Conclusions: The changes to stable isotopic ratios observed during the preparation of MDA and MDP2P from piperonal may prove useful when attempting to compare batch-to-batch variations between seizures and provide information with tactical intelligence applications.