Mass spectrometric properties of N-(2-methoxybenzyl)-2-(2,4,6-trimethoxyphenyl)ethanamine (2,4,6-TMPEA-NBOMe), a new representative of designer drugs of NBOMe series and derivatives thereof

Emergence of new psychoactive substances, hallucinogenic phenethylamines in particular, in illicit market is a serious threat to human health in global scale. We have detected and identified N-(2-methoxybenzyl)-2-(2,4,6-trimethoxyphenyl)ethanamine (2,4,6-TMPEA-NBOMe), a new compound in NBOMe series. Identification was achieved by means of gas chromatography/mass spectrometry (GC/MS), including high-resolution mass spectrometry with tandem experiments (GC/HRMS and GC/HRMS² ), ultra-high performance liquid chromatography/high-resolution mass spectrometry with tandem experiments (UHPLC/HRMS and UHPLC/HRMS² ), and ¹ H and ¹³ C nuclear magnetic resonance spectroscopy. The peculiarities of fragmentation of the compound under electron ionization (EI) and collision-induced dissociation were studied. Despite of the empirical rule denying migration of the hydrogen atom in McLafferty rearrangement to the benzene ring with substituents in the both ortho-positions, it easily occurs for 2,4,6-TMPEA-NBOMe in EI conditions. We have noticed that electron-donating substituents, e.g. methoxy groups in the both ortho-positions and para-positions favor the rearrangement. For specially synthesized N-methyl and N-acyl derivatives McLafferty rearrangement is not observed. N-Acyl derivatives demonstrate McLafferty rearrangement, but the charge retains at the alternative fragment involving N-acyl carbonyl group. We have also showed that the hydrogen atoms in 2,4,6-trimethoxybenzene ring may be easily substituted for deuterium or for strong electrophiles like trifluoroacetyl. Analytical characteristics of 2,4,6-TMPEA-NBOMe and of some derivatives thereof which enable their determination in various criminal seizures are given. Copyright © 2016 John Wiley & Sons, Ltd.