Identification of specific markers for amphetamines synthesized from glycidic acid pre-precursors and retrospective...

The pre-precursor market and the clandestine production of amphetamine-type stimulants (ATS) has become more diverse in recent years. Besides α-phenylacetoacetonitrile (APAAN) and α-phenylacetoacetamide (APAA), glycidic acid derivatives and methyl α-phenylacetoacetate (MAPA) are gaining importance. This conclusion is based on seizure data of police and customs. However, analytical data are needed to confirm and quantify the actual prevalence of new pre-precursors by elucidating the percentage of seized ATS that have been produced from them. A recent study showed that APAAN use is currently declining, which supports the view that new pre-precursors are being used. In this study, several conversion procedures using different batches of glycidic acid derivatives and a complete Leuckart reaction to produce amphetamine were carried out. The resulting organic phases were analyzed using gas chromatography - mass spectrometry to identify possible marker compounds. Three marker compounds were discovered and characterized using mass spectra and nuclear magnetic resonance spectroscopy. They were identified as phenyl-1-propanone, N-(1-phenylpropyl)formamide and 1-phenylpropan-1-amine. Their prevalence was investigated by searching the markers in an amphetamine impurity profiling database to determine to what extent they occurred in amphetamine samples from recent years. Data from the central German amphetamine profiling database of more than 250 cases were used for this purpose. The yearly occurrence of the three glycidate marker compounds was determined going back as far as 2009, revealing an increasing trend from 2016 on. This article presents experimental proof that APAAN is currently being replaced by other pre-precursors, such as glycidic acid derivatives.