Identification of seven psychedelic 2,5-dimethoxy-phenylethyl-amine-based designer drugs via benchtop 1 H nuclear magnetic resonance spectroscopy.

The dissemination of spectral information of new psychoactive substances (NPS) acquired on benchtop nuclear magnetic resonance (NMR) spectrometers is of high importance considering the emerging application of such portable and accessible instruments in forensic analyses. Seven members of the 2C-X series (2C-B, 2C-C, 2C-D, 2C-E, 2C-P, 2C-T2, and 2C-T7) of NPS were analyzed via 60 MHz 1 H benchtop NMR spectroscopy and their molecular structural relations are discussed with respect to the observed proton NMR spectra.

3,4-Methylenedioxymethamphetamine quantification via benchtop 1H qNMR spectroscopy: Method validation and its application to ecstasy tablets collected at music festivals.

We describe a method validation for the quantification of 3,4-methylenedioxymethamphetamine (MDMA) in tablets based on the United Nations Office on Drugs and Crime (UNODC) guideline for quantitative Nuclear Magnetic Resonance analysis (qNMR). qNMR experiments were carried out on a 60 MHz benchtop NMR spectrometer employing ethylene carbonate as an internal calibrant. A series of 'ecstasy' tablets seized at music events were quantified and the results discussed regarding their within-batch variation and yearly median dose. The method showed good specificity and selectivity, with linearity, precision, accuracy, and recovery well within the UNODC recommended criteria. The limit of detection and quantification are 0.33 mg/mL and 0.10 mg/mL respectively, proving the method works well on small amounts of MDMA. Overall, the lowest amount of MDMA free base detected in this study was 9.35 mg in a piperazine mix, while the highest dosed tablet contained 237.55 mg MDMA free base, with a 9.1% decrease in median amount compared to the pre-pandemic data (2019), but still higher than the data collected in a previous study (105 mg median amount of MDMA free base in 2018). The within-batch variation was insignificant for one of the seizures but showed greater variation for the other, which confirmed that the MDMA content of a single tablet may not reflect that of the whole batch. This dynamic upward change in tablet dosage highlights the importance of ongoing trend monitoring and specific prevention intervention to counteract the negative consequences associated with MDMA use. Benchtop NMR has been successfully employed in quality control, material science and more recently, drug analysis. The present study demonstrates its beneficial application in forensic science overcoming the limitations of currently available instruments and techniques employed in harm reduction and field testing.

Borane-Catalyzed Synthesis of Quinolines Bearing Tetrasubstituted Stereocenters by Hydride Abstraction-Induced Electrocyclization.

The borane-catalyzed synthesis of quinoline derivatives bearing tetrasubstituted stereocenters from vinyl anilines has been developed. Mechanistic studies and quantum-mechanical investigations support the hydride abstraction/electrocyclization/hydride addition mechanism. The products were obtained in up to 99 % yield with a diastereoselectivity of >99 % in favour for the 3a-5-cis isomer.

Frustrated Lewis Pair Catalyzed Dehydrogenative Oxidation of Indolines and Other Heterocycles.

An acceptorless dehydrogenation of heterocycles catalyzed by frustrated Lewis pairs (FLPs) was developed. Oxidation with concomitant liberation of molecular hydrogen proceeded in high to excellent yields for N-protected indolines as well as four other substrate classes. The mechanism of this unprecedented FLP-catalyzed reaction was investigated by mechanistic studies, characterization of reaction intermediates by NMR spectroscopy and X-ray crystal analysis, and by quantum-mechanical calculations. Hydrogen liberation from the ammonium hydridoborate intermediate is the rate-determining step of the oxidation. The addition of a weaker Lewis acid as a hydride shuttle increased the reaction rate by a factor of 2.28 through a second catalytic cycle.