Synthesis and pharmacological evaluation of ring-methylated derivatives of 3,4-(methylenedioxy)amphetamine (MDA)

Copper Catalyzed Regioselective and Stereospecific Aziridine Opening with Pyridyl Grignard Nucleophiles

Copper catalyzed regioselective and stereospecific coupling between aziridines and in situ generated pyridine Grignard reagents is reported. This method provides β-pyridylethylamines with diverse structures and functionalities from aziridines and iodopyridines. β-Pyridylethylamines are potential scaffolds for the synthesis of biologically active compounds often found in pharmaceuticals. The synthesis of challenging chiral dihydroazaindoles was also achieved through mild one-pot reaction conditions via aziridine opening followed by nucleophilic cyclization.

Merging Photoredox/Nickel Catalysis for Cross-Electrophile Coupling of Aziridines with Pyridin-1-ium Salts via Dearomatization

Merging photoredox/nickel catalysis enabling the cross-electrophile coupling of aziridines with pyridin-1-ium salts involving dearomatization for the synthesis of β-(1,4-dihydropyridin-4-yl)-ethylamines, especially including bioactive motif-based analogues, is described. This method allows incorporation of a 1,4-dihydropyridin-4-yl group and formation a N-H amino group to construct highly valuable β-(1,4-dihydropyridin-4-yl)-ethylamine frameworks in a single step through the C2-N bond regioselective cleavage and dearomatization alkylation cascades with precise regioselectivity and excellent functional group tolerance, and represents an appealing cross-electrophile coupling strategy to accomplish transformations between two electrophiles, including aziridines and pyridin-1-ium salts, by avoiding prefunctionalization.

Synthesis of β-Phenethylamines via Ni/Photoredox Cross-Electrophile Coupling of Aliphatic Aziridines and Aryl Iodides

A photoassisted Ni-catalyzed reductive cross-coupling between tosyl-protected alkyl aziridines and commercially available (hetero)aryl iodides is reported. This mild and modular method proceeds in the absence of stoichiometric heterogeneous reductants and uses an inexpensive organic photocatalyst to access medicinally valuable β-phenethylamine derivatives. Unprecedented reactivity was achieved with the activation of cyclic aziridines. Mechanistic studies suggest that the regioselectivity and reactivity observed under these conditions are a result of nucleophilic iodide ring opening of the aziridine to generate an iodoamine as the active electrophile. This strategy also enables cross-coupling with Boc-protected aziridines.

Aromatic Bromination Abolishes the Psychomotor Features and Pro-social Responses of MDMA ("Ecstasy") in Rats and Preserves Affinity for the Serotonin Transporter (SERT)

The entactogen MDMA (3,4-methylenedioxy-methamphetamine, “Ecstasy”) exerts its psychotropic effects acting primarily as a substrate of the serotonin transporter (SERT) to induce a non-exocytotic release of serotonin. Nevertheless, the roles of specific positions of the aromatic ring of MDMA associated with the modulation of typical entactogenic effects, using analogs derived from the MDMA template, are still not fully understood. Among many possibilities, aromatic halogenation of the phenylalkylamine moiety may favor distribution to the brain due to increased lipophilicity, and sometimes renders psychotropic substances of high affinity for their molecular targets and high potency in humans. In the present work, a new MDMA analog brominated at C(2) of the aromatic ring (2-Br-4,5-MDMA) has been synthesized and pharmacologically characterized in vitro and in vivo. First, binding competition experiments against the SERT-blocker citalopram were carried out in human platelets and compared with MDMA. Besides, its effects on platelet aggregation were performed in platelet enriched human plasma using collagen as aggregation inductor. Second, as platelets are considered an appropriate peripheral model for estimating central serotonin availability, the functional effects of 2-Br-4,5-MDMA and MDMA on ATP release during human platelet aggregation were evaluated. The results obtained showed that 2-Br-4,5-MDMA exhibits higher affinity for SERT than MDMA and fully abolishes both platelet aggregation and ATP release, resembling the pharmacological profile of citalopram. Subsequent in vivo evaluation in rats at three dose levels showed that 2-Br-4,5-MDMA lacks all key MDMA-like behavioral responses in rats, including hyperlocomotion, enhanced active avoidance conditioning responses and increased social interaction. Taken together, the results obtained are consistent with the notion that 2-Br-4,5-MDMA should not be expected to be an MDMA-like substrate of SERT, indicating that aromatic bromination at C(2) modulates the pharmacodynamic properties of the substrate MDMA, yielding a citalopram-like compound.

Dark Classics in Chemical Neuroscience: 3,4-Methylenedioxymethamphetamine

Better known as "ecstasy", 3,4-methylenedioxymethamphetamine (MDMA) is a small molecule that has played a prominent role in defining the ethos of today's teenagers and young adults, much like lysergic acid diethylamide (LSD) did in the 1960s. Though MDMA possesses structural similarities to compounds like amphetamine and mescaline, it produces subjective effects that are unlike any of the classical psychostimulants or hallucinogens and is one of the few compounds capable of reliably producing prosocial behavioral states. As a result, MDMA has captured the attention of recreational users, the media, artists, psychiatrists, and neuropharmacologists alike. Here, we detail the synthesis of MDMA as well as its pharmacology, metabolism, adverse effects, and potential use in medicine. Finally, we discuss its history and why it is perhaps the most important compound for the future of psychedelic science-having the potential to either facilitate new psychedelic research initiatives, or to usher in a second Dark Age for the field.

Regulation of the dopamine transporter: aspects relevant to psychostimulant drugs of abuse

Dopaminergic signaling in the brain is primarily modulated by dopamine transporters (DATs), which actively translocate extraneuronal dopamine back into dopaminergic neurons. Transporter proteins are highly dynamic, continuously trafficking between plasmalemmal and endosomal membranes. Changes in DAT membrane trafficking kinetics can rapidly regulate dopaminergic tone by altering the number of transporters present at the cell surface. Various psychostimulant DAT ligands-acting either as amphetamine-like substrates or cocaine-like nontranslocated inhibitors-affect transporter trafficking, triggering rapid insertion or removal of plasmalemmal DATs. In this review, we focus on the effects of psychostimulants of addiction (particularly D-methamphetamine and cocaine) on DAT regulation and membrane trafficking, with an emphasis on how these drugs may influence intracellular signaling cascades and transporter-associated scaffolding proteins to affect DAT regulation. In addition, we consider involvement of presynaptic receptors for dopamine and other ligands in DAT regulation. Finally, we discuss possible implications of transporter regulation to the putative toxicity of several substituted amphetamine derivatives commonly used as recreational drugs, as well as to the design of therapeutics for cocaine addiction.

Delayed onset of seizures and toxicity associated with recreational use of Bromo-dragonFLY

INTRODUCTION

Many countries have specific legislation, such as the Controlled Substances Act (1970) in the United States and the Misuse of Drugs Act (1971) in the United Kingdom to control recreational drugs. There is a growing market and supply of "novel" recreational drugs, which include the misuse of pharmaceutical compounds and research chemicals. These are often not covered under current legislation, despite the fact that they often have both similar chemical structures and/or clinical effects to controlled recreational drugs.

CASE REPORT

A male patient presented to an emergency department with delayed onset of severe agitation, hallucinations, and tonic-clonic seizures following the use of Bromo-dragonFLY and an unknown white powder. He settled following IV benzodiazepines and supportive care, and was discharged with no evidence of long-term sequelae. Analysis of the white powder by gas chromatography/mass spectrometry (GC/MS), ultraviolet/visible spectrophotometry (UV/VIS) and thin layer chromatography (TLC) showed the presence of Bromo-dragonFLY (1-(8-bromobenzo[1,2-b;4,5-b']difuran-4-yl)-2-aminopropane); serum analysis by GC/MS and liquid chromatography with tandem mass spectrometry (LC/MS/MS) confirmed that a combination of Bromo-dragonFLY (0.95 ng/mL), ketamine (20 ng/mL) and cannabis had been used by the patient. No other recreational drugs were detected in an extensive toxicological screen of serum and urine samples.

DISCUSSION

This is the first confirmed case to be reported of toxicity with delayed onset of severe agitation, hallucinations and tonic-clonic seizures associated with recreational use of Bromo-dragonFLY (1-(8-bromobenzo[1,2-b;4,5-b']difuran-4-yl)-2-aminopropane) in combination with ketamine and cannabis. In our view, this case provides further support for the need for a systematic approach to toxicological screening of patients with recreational drug toxicity, to identify emerging drugs and provide evidence for legislative authorities to assist in revising the legal status of emerging recreational drugs.

Electrochemical and spectroscopic characterisation of amphetamine-like drugs: Application to the screening of 3,4-methylenedioxymethamphetamine (MDMA) and its synthetic precursors

A complete physicochemical characterisation of MDMA and its synthetic precursors MDA, 3,4-methylenedioxybenzaldehyde (piperonal) and 3,4-methylenedioxy-beta-methyl-beta-nitrostyrene was carried out through voltammetric assays and Raman spectroscopy combined with theoretical (DFT) calculations. The former provided important analytical redox data, concluding that the oxidative mechanism of the N-demethylation of MDMA involves the removal of an electron from the amino-nitrogen atom, leading to the formation of a primary amine and an aldehyde. The vibrational spectroscopic experiments enable to afford a rapid and reliable detection of this type of compounds, since they yield characteristic spectral patterns that lead to an unequivocal identification. Moreover, the rational synthesis of the drug of abuse 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") from one of its most relevant precursors 3,4-methylene-dioxyamphetamine (MDA), is reported. In addition, several approaches for the N-methylation of MDA, a limiting synthetic step, were attempted and the overall yields compared.

Rapid simultaneous determination of ephedrines, amphetamines, cocaine, cocaine metabolites, and opiates in human urine by GC-MS

This paper presents a simple and sensitive chromatographic procedure for the simultaneous determination and quantification of ephedrines, amphetamines, cocaine, cocaine metabolites, and opiates in human urine by gas chromatography-mass spectrometry. This method involves enzyme hydrolysis in the presence of a deuterated internal standard, liquid-liquid extraction, and derivatization with pentafluoropropionic anhydride and pentafluoropropanol. The recovery of each compound averaged at 65.8% or more. The limits of detection determined for each compound by using a 2-mL sample volume ranged from 5 to 50 ng/mL. The calibration curves were linear to 100 ng/mL for all compounds when determined using methamphetamine-d4 and MDMA-d5 as internal standards. This method was successfully applied for the analysis of urine samples suspected to contain intoxicants such as methamphetamine and heroin.

Synthesis of Fluoro Analogues of 3,4-(Methylenedioxy)amphetamine (MDA) and Its Derivatives

The role of the metabolism of the entactogen 3,4-(methylenedioxy)methamphetamine (MDMA; 1b) in neurotoxic or psychopharmacologic action is widely discussed, but not yet fully understood. To prompt further investigation into the role of MDMA metabolism, six new 3,4-(difluoromethylenedioxy) analogues of MDMA (1b) were prepared and characterized. Although electronically very different, the fluoro analogues 3-5 should be sterically very similar to the non-fluorinated parent compounds. The F-atoms may prevent the formation of toxic metabolites produced via a radical pathway (Scheme 1). Different theories regarding MDMA-induced neurotoxicity are briefly reviewed and discussed. The novel compounds 3-5 may help to verify the hypothesis that MDMA-induced neurotoxicity is the result of the formation of metabolites lacking the methylenedioxy bridge.

Beta-nitrostyrene derivatives as potential antibacterial agents: a structure-property-activity relationship study

A multidisciplinary project was developed, combining the synthesis of a series of beta-nitrostyrene derivatives and the determination of their physicochemical parameters (redox potentials, partition coefficients), to the evaluation of the corresponding antibacterial activity. A complete conformational analysis was also performed, in order to get relevant structural information. Subsequently, a structure-property-activity (SPAR) approach was applied, through linear regression analysis, aiming at obtaining a putative correlation between the physicochemical parameters of the compounds investigated and their antibacterial activity (both against standard strains and clinical isolates). The beta-nitrostyrene compounds displayed a lower activity towards all the tested bacteria relative to the beta-methyl-beta-nitrostyrene analogues. This was observed particularly for the 3-hydroxy-4-methoxy-beta-methyl-beta-nitrostyrene (IVb) against the Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium). The SPAR results revealed the existence of a clear correlation between the redox potentials and the antibacterial activity of the series of beta-nitrostyrene derivatives under study.