Synthesis and characterization of 5-methoxy-2- methyl-N,N-dialkylated tryptamines Simon D. Brandt, a * Ruchanok Tearavarich, b Nicola Dempster, a Nicholas V. Cozzi c and Paul F. Daley d The absence of reference material is a commonly experienced difficulty among medical and forensic professionals tasked with identifying new psychoactive substances that are encountered for the first time. The identification of newly emerging substances lies at the heart of forensic and clinical analysis, and a proactive public health policy calls for a thorough analysis of the properties of new psychoactive substances before they appear in the emergency clinic, where they may be noticed because of adverse reac- tions or toxicity. For example, a wide range of N,N-dialkyltryptamines show psychoactive properties in humans and these trypta- mines are sometimes encountered as intoxicants. However, most of the existing reference data on new psychoactive tryptamines have been obtained retrospectively, after reports of acute toxicities. To address the need for reference standards for new trypta- mines, thirteen 5-methoxy-2-methyl-N,N-dialkyltryptamines were prepared. Analytical characterization was based on 1 H and 13 C nuclear magnetic resonance (NMR), gas chromatography-electron ionization ion-trap mass spectrometry (GC-EI-IT-MS) and chem- ical ionization-ion-trap tandem mass spectrometry (CI-IT-MS/MS), respectively. Differentiation among isomers was feasible by NMR and MS. In addition to the expected iminium ion base peak, indole-related key ions were detected under EI-IT-MS conditions at m/z 174, 159, 131, 130, and 103. CI-IT-MS/MS analysis of the 5-methoxy-2-methyl derivatives revealed the presence of m/z 188 in addition to [M+H] + and the iminium species. This study served as an extension from previous work on isomeric 5-ethoxylated counterparts and confirmed the ability to differentiate between the two groups. The data provided here add to the existing body of literature and aim to serve both forensic and clinical communities. Copyright © 2012 John Wiley & Sons, Ltd. Keywords: tryptamines; microwave; psychoactive; receptor probes; nuclear magnetic resonance; mass spectrometry Introduction 5 - Methoxy - 2 - methyl - N,N - dimethyltryptamine (5 - MeO-2-Me-DMT, MMDT) 1 and its 2-ethyl homologue (EMDT) (Figure 1) have been shown to be h5-HT 6 -selective agents with K i values of 16 and 60 nM ([ 3 H]LSD as radioligand), respectively. [1] In recent years, the 5-HT 6 receptor subtype has been the target of intensive research activities in the attempt to find effective strategies for the treatment of central nervous system (CNS) related diseases. [2–4] Functional studies using the cAMP assay revealed that both 1 and EMDT behaved as ago- nists whereas 5 - methoxy-2-phenyl-N, N-dimethyltryptamine (PMDT) (K i = 20 nM) exhibited antagonist character. [1] In addition, the pyrroli- dine derivative of EMDT (EMDT-A) displayed stereoselective binding (8R K i = 1.8 and 8S K i = 220 nM). [5] On the other hand, the closely related 5-methoxy-N, N-dimethyltryptamine (5-MeO-DMT, Fig. 1) (K i = 13 nM [6] ) shows powerful psychoactive/hallucinogenic effects in humans [7,8] which exemplifies the need to under- stand the delicate interactions involved between medicinal and psychoactive drugs and their molecular targets. Indeed, many N,N-dialkylated tryptamines, such as N, N-dimethyltryptamine (DMT, Figure 1) show psychoactive properties in humans and while several N,N-dimethyl derivatives are abundantly available in nature, most of the currently known derivatives are of synthetic origin that display a pharmacologically rich profile of receptor interactions. [7,9–13] While it can be appreciated that structural modifications of biologically active templates form the basis of any form of drug discovery, it has also become obvious that many psycho- active derivatives have appeared on the recreational drug market, for example, in the form of so-called research chemi- cals. [14] A wide range of compound classes have emerged in recent years which extended beyond the tryptamine nu- cleus [15] and increasing availability raises concerns about un- controlled patterns of consumption in a recreational and non-clinical context. Developing effective and efficient responses to new psychoactive substances is a major chal- lenge to public health. This is particularly apparent in an in- creasingly globalized market where the Internet is playing an important role in supply. [14,16] The identification and characterization of newly emerging substances lies at the heart of forensic and clinical analysis and a proactive public health policy calls for a thorough analysis of the properties of new psychoactive substances before they * Correspondence to: Simon Brandt, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK. E-mail: s.brandt@ljmu.ac.uk a School of Pharmacy and Biomolecular Sciences, Liverpool John Moores Univer- sity, Liverpool, UK b Department of Chemistry, Faculty of Engineering, Rajamangala University of Technology Isan, Khon Kaen Campus, Khon Kaen 40000, Thailand c Neuropharmacology Laboratory, Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA d Alexander Shulgin Research Institute, 1483 Shulgin Road, Lafayette, Lafayette, CA 94549, USA Drug Test. Analysis 2012, 4, 24–32 Copyright © 2012 John Wiley & Sons, Ltd. Research article Drug Testing and Analysis Received: 4 October 2011 Revised: 29 October 2011 Accepted: 12 November 2011 Published online in Wiley Online Library (wileyonlinelibrary.com) DOI 10.1002/dta.398 24