Impurity profiling of methamphetamine synthesised from α-phenylacetoacetonitrile (APAAN).

The rise in popularity of 'designer' precursor compounds for the synthesis of amphetamine-type stimulants poses a significant challenge to law enforcement agencies. One such precursor is α-phenylacetoacetonitrile (APAAN). APAAN emerged in Europe in 2010 and quickly became one of the most popular precursors for amphetamine synthesis in that region. Previous literature has identified four APAAN-specific impurities formed in the synthesis of amphetamine; however, there is currently no research on the use of APAAN in the synthesis of methamphetamine, which is more likely to be employed in a non-European market. In this study methamphetamine was synthesised via three common clandestine methods: the Leuckart method and two reductive amination methods. We report the identification of five new impurities and two previously identified impurities characteristic for the use of APAAN in the synthesis of methamphetamine. The newly identified impurities were characterised by MS and NMR and determined to be (E)-3-(methylamino)-2-phenylbut-2-enenitrile, 3-(methylamino)-2-phenylbutanenitrile, 3-methyl-2,4-diphenylpentanedinitrile, 2-phenylbutyronitrile and 3-hydroxy-2-phenylbutanenitrile.

Pharmacological Neuroenhancement: Current Aspects of Categorization, Epidemiology, Pharmacology, Drug Development, Ethics, and Future Perspectives.

Recent pharmacoepidemiologic studies suggest that pharmacological neuroenhancement (pNE) and mood enhancement are globally expanding phenomena with distinctly different regional characteristics. Sociocultural and regulatory aspects, as well as health policies, play a central role in addition to medical care and prescription practices. The users mainly display self-involved motivations related to cognitive enhancement, emotional stability, and adaptivity. Natural stimulants, as well as drugs, represent substance abuse groups. The latter comprise purines, methylxanthines, phenylethylamines, modafinil, nootropics, antidepressants but also benzodiazepines, ß-adrenoceptor antagonists, and cannabis. Predominant pharmacodynamic target structures of these substances are the noradrenergic/dopaminergic and cholinergic receptor/transporter systems. Further targets comprise adenosine, serotonin, and glutamate receptors. Meta-analyses of randomized-controlled studies in healthy individuals show no or very limited verifiability of positive effects of pNE on attention, vigilance, learning, and memory. Only some members of the substance abuse groups, i.e., phenylethylamines and modafinil, display positive effects on attention and vigilance that are comparable to caffeinated drinks. However, the development of new antidementia drugs will increase the availability and the potential abuse of pNE. Social education, restrictive regulatory measures, and consistent medical prescription practices are essential to restrict the phenomenon of neuroenhancement with its social, medical, and ethical implications. This review provides a comprehensive overview of the highly dynamic field of pharmacological neuroenhancement and elaborates the dramatic challenges for the medical, sociocultural, and ethical fundaments of society.

Structure-activity relationships for a series of (Bis(4-fluorophenyl)methyl)sulfinylethyl-aminopiperidines and -piperidine amines at the dopamine transporter: Bioisosteric replacement of the piperazine improves metabolic stability.

Despite considerable efforts to develop medications to treat psychostimulant use disorders, none have proven effective, leaving an underserved patient population and unanswered questions as to what mechanism(s) of action should be targeted for developing pharmacotherapies. Atypical dopamine transporter (DAT) inhibitors, based on (±)modafinil, have shown therapeutic potential in preclinical models of psychostimulant abuse. However, metabolic instability among other limitations to piperazine analogues 1-3 have impeded further development. Herein, bioisosteric substitutions of the piperazine ring were explored with a series of aminopiperidines (A) and piperidine amines (B) wherein compounds with either a terminal tertiary amine or amide were synthesized. Several lead compounds showed high to moderate DAT affinities and metabolic stability in rat liver microsomes. Aminopiperidines 7 (DAT Ki = 50.6 nM), 21b (DAT Ki = 77.2 nM) and 33 (DAT Ki = 30.0 nM) produced only minimal stimulation of ambulatory activity in mice, compared to cocaine, suggesting an atypical DAT inhibitor profile.

Syntheses and analytical characterizations of novel (2-aminopropyl)benzo[b]thiophene (APBT) based stimulants.

Two groups of amphetamine-like drugs with psychostimulant properties that were first developed during the course of scientific studies and later emerged as new psychoactive substances (NPS) are based on the (2-aminopropyl)indole (API) and (2-aminopropyl)benzofuran (APB) structural scaffolds. However, sulfur-based analogs with a benzo[b]thiophene structure (resulting in (2-aminopropyl)benzo[b]thiophene (APBT) derivatives) have received little attention. In the present investigation, all six racemic APBT positional isomers were synthesized in an effort to understand their structure-activity relationships relative to API- and APB-based drugs. One lesson learned from the NPS phenomenon is that one cannot exclude the appearance of such substances on the market. Therefore, an in-depth analytical characterization was performed, including various single- and tandem mass spectrometry (MS) and ionization platforms coupled to gas chromatography (GC) and liquid chromatography (LC), nuclear magnetic resonance spectroscopy (NMR), and solid phase and GC condensed phase infrared spectroscopy (GC-sIR). Various derivatizations have also been explored; it was found that all six APBT isomers could be differentiated during GC analysis after derivatization with heptafluorobutyric anhydride and ethyl chloroformate (or heptafluorobutyric anhydride and acetic anhydride) under non-routine conditions. Discriminating analytical features can also be derived from NMR, GC-EI/CI- single- and tandem mass spectrometry, LC (pentafluorophenyl stationary phase), and various infrared spectroscopy approaches (including GC-sIR). Availability of detailed analytical data obtained from these novel APBT-type stimulants may be useful to researchers and scientists in cases where forensic and clinical investigations are warranted.

Synthetic cathinones - From natural plant stimulant to new drug of abuse.

As recreational substances, synthetic cathinones started to be used at the beginning of the 21st century. There is still limited data on these compounds, introduced to the illicit drug market for the most part after 2009. Considering that synthetic cathinones are currently the second largest group of new psychoactive and dangerous substances among over 670 new psychoactive substances identified in Europe and monitored by the EMCDDA, research on them should be regarded as extremely important. This review focuses on the availability of synthetic cathinones on the illicit drug market, presentation of current trends in the use of these substances, and their mechanisms of action and toxicity. The authors discuss cases of intoxication with synthetic cathinones and post-mortem diagnostics as well as the problem of combined used of synthetic cathinones with other psychoactive substances. Literature as well as clinical and forensic data indicate the need for further research on the metabolism, toxicokinetics, toxicodynamics, clinical effects, and addictive potential of synthetic cathinones, especially in the context of potential threats caused by increased consumption of this group of drugs in future.

Identification of specific markers for amphetamines synthesized from glycidic acid pre-precursors and retrospective search in German profiling database.

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.

Synthesis and Biological Evaluation of Novel 2,3-disubstituted Benzofuran Analogues of GABA as Neurotropic Agents.

BACKGROUND: Benzofurans are heterocyclic compounds with neurotropic activity. Some have been developed for the treatment of acute and degenerative neuronal injuries. OBJECTIVE: The study aimed to evaluate the in silico binding of some promising benzofurans on the GABA receptors, and the in vivo neurotropic activity of benzofuran analogues (BZF 6-10) of gamma-aminobutyric acid (GABA) on a seizure model. METHODS: The ligands with the best physicochemical attributes were docked on two GABA receptors (the alpha-1 subunit of GABAA-R and GBR1 subunit of GABAB-R). Selected benzofuran derivatives were synthesized by a multistep procedure and characterized. To examine the neurotropic effects, mice were pretreated with different concentrations of the compounds prior to PTZ- or 4- AP-induced seizures. We assessed acute toxicity, motor behavior, and the effects on seizures. RESULTS: The tested ligands that complied with Lipinski's rule of five were tested in silico with GABAA-R (ΔG = -5.51 to -5.84 kcal/mol) at the allosteric site for benzodiazepines. They bound to a similar cluster of residues as the reference compound (gaboxadol, ΔG = -5.51 kcal/mol). Synthesis was achieved with good overall yields (42-9.7%). Two compounds were selected for biological tests (BZF-7 and rac-BZF-10) on a mouse model of seizures, induced by pentylenetetrazol (PTZ) or 4-aminopyridine (4-AP). PTZ-induced seizures are associated with GABA receptors, and those 4-AP-induced with the blockage of the delayed rectifier-type potassium channel, which promotes the release of the NMDA-sensitive glutamatergic ionotropic receptor and other neurotransmitters. The biological assays demonstrated that BZF-7 and rac-BZF-10 do not protect against seizures. Indeed, BZF-7 increased the number of PTZ-induced seizures and decreased latency time. The 4-AP model apparently showed a potentiation of seizure effects after administration of the BZF-analogues, evidenced by the incidence and severity of the seizures and reduced latency time. CONCLUSION: The results suggest that the test compounds are GABAergic antagonists with stimulatory activity on the CNS.

Synthetic cathinone adulteration of illegal drugs.

RATIONALE: Current prevalence estimates of synthetic cathinone ("bath salt") use may be underestimates given that traditional metrics (e.g., surveys, urinalysis) often fail to capture the emergent issue of synthetic cathinone adulteration of more common illegal drugs, such as ecstasy (3,4-methylenedioxymethamphetamine). OBJECTIVES: This review examines the evolution of synthetic cathinones and prevalence of use over the past decade in the United States. We also review methods of self-report and biological testing of these compounds as well as adverse outcomes associated with adulterated drug use. RESULTS: Synthetic cathinone use emerged in the United States by 2009 with use associated with tens of thousands of poisonings. Reported poisonings and self-reported use have substantially decreased over the past five years. However, our review suggests that current estimates of use are underestimates due to underreporting stemming primarily from unknown or unintentional use of adulterated formulations of relatively popular illegal drugs, such as ecstasy. CONCLUSIONS: While intentional synthetic cathinone use has decreased in recent years, evidence suggests that prevalence of use is underestimated. Testing of drugs and/or biological specimens can improve the accuracy of synthetic cathinone use estimates. Furthermore, we advocate that researchers and clinicians should become better aware that exposure to these potent compounds (e.g., as adulterants) often occurs unknowingly or unintentionally. To improve our understanding of synthetic cathinone adulteration, research utilizing a combinatorial approach (survey and biological testing) will help more accurately estimate the prevalence and impact of this public health issue.

Neuropharmacology of Synthetic Cathinones.

Synthetic cathinones are derivatives of the naturally occurring compound cathinone, the main psychoactive ingredient in the khat plant Catha edulis. Cathinone is the ß-keto analog of amphetamine, and all synthetic cathinones display a ß-keto moiety in their structure. Several synthetic cathinones are widely prescribed medications (e.g., bupropion, Wellbutrin®), while others are problematic drugs of abuse (e.g., 4-methylmethcathinone, mephedrone). Similar to amphetamines, synthetic cathinones are psychomotor stimulants that exert their effects by impairing the normal function of plasma membrane transporters for dopamine (DAT), norepinephrine (NET), and 5-HT (SERT). Ring-substituted cathinones like mephedrone are transporter substrates that evoke neurotransmitter release by reversing the normal direction of transporter flux (i.e., releasers), whereas pyrrolidine-containing cathinones like 3,4-methylenedioxypyrovalerone (MDPV) are potent transporter inhibitors that block neurotransmitter uptake (i.e., blockers). Regardless of molecular mechanism, all synthetic cathinones increase extracellular monoamine concentrations in the brain, thereby enhancing cell-to-cell monoamine signaling. Here, we briefly review the mechanisms of action, structure-activity relationships, and in vivo pharmacology of synthetic cathinones. Overall, the findings show that certain synthetic cathinones are powerful drugs of abuse that could pose significant risk to users.

DARK Classics in Chemical Neuroscience: Methamphetamine.

Methamphetamine has the second highest prevalence of drug abuse after cannabis, with estimates of 35 million users worldwide. The ( S)-(+)-enantiomer is the illicit drug, active neurostimulant, and eutomer, while the ( R)-(-)-enantiomer is contained in over the counter decongestants. While designated a schedule II drug in 1970, ( S)-(+)-methamphetamine is available by prescription for the treatment of attention-deficit disorder and obesity. The illicit use of ( S)-(+)-methamphetamine results in the sudden "rush" of stimulation to the motivation, movement, pleasure, and reward centers in the brain, caused by rapid release of dopamine. In this review, we will provide an overview of the synthesis, pharmacology, adverse effects, and drug metabolism of this widely abused psychostimulant that distinguish it as a DARK classic in Chemical Neuroscience.

Detailed investigations into the Akabori-Momotani reaction for the synthesis of amphetamine type stimulants: Part 2.

The Akabori-Momotani reaction can be used to synthesise pseudoephedrine in 50% yield from N-methylalanine and benzaldehyde. This paper investigates electronic effects of substituted benzaldehydes on the reaction to synthesise amphetamine type stimulants and identifies several new Akabori-Momotani by-products, 1-[(4-methoxybenzyl)(methyl)amino]ethanol (11c), 2-(4-methoxyphenyl)-3,4-dimethyl-1,3-oxazolidine (12c), 1,2,3,4-tetramethyl-5,6-di-(4-methoxyphenyl)piperazine (13c) and 1,2,4,5-tetramethyl-3,6-di-(4-methoxyphenyl)piperazine (14c). This paper also investigates pseudoephedrine and methamphetamine isomeric distribution from the Akabori-Momotani reaction with the aid of molecular modelling to understand why more pseudoephedrine than ephedrine is produced.

The DARK Side of Total Synthesis: Strategies and Tactics in Psychoactive Drug Production.

Humankind has used and abused psychoactive drugs for millennia. Formally, a psychoactive drug is any agent that alters cognition and mood. The term "psychotropic drug" is neutral and describes the entire class of substrates, licit and illicit, of interest to governmental drug policy. While these drugs are prescribed for issues ranging from pain management to anxiety, they are also used recreationally. In fact, the current opioid epidemic is the deadliest drug crisis in American history. While the topic is highly politicized with racial, gender, and socioeconomic elements, there is no denying the toll drug mis- and overuse is taking on this country. Overdose, fueled by opioids, is the leading cause of death for Americans under 50 years of age, killing ca. 64,000 people in 2016. From a chemistry standpoint, the question is in what ways, if any, did organic chemists contribute to this problem? In this targeted review, we provide brief historical accounts of the main classes of psychoactive drugs and discuss several foundational total syntheses that ultimately provide the groundwork for producing these molecules in academic, industrial, and clandestine settings.

Identification of specific markers for amphetamine synthesised from the pre-precursor APAAN following the Leuckart route and retrospective search for APAAN markers in profiling databases from Germany and the Netherlands.

α-Phenylacetoacetonitrile (APAAN) is one of the most important pre-precursors for amphetamine production in recent years. This assumption is based on seizure data but there is little analytical data available showing how much amphetamine really originated from APAAN. In this study, several syntheses of amphetamine following the Leuckart route were performed starting from different organic compounds including APAAN. The organic phases were analysed using gas chromatography-mass spectrometry (GC-MS) to search for signals caused by possible APAAN markers. Three compounds were discovered, isolated, and based on the performed syntheses it was found that they are highly specific for the use of APAAN. Using mass spectra, high resolution MS and nuclear magnetic resonance (NMR) data the compounds were characterised and identified as 2-phenyl-2-butenenitrile, 3-amino-2-phenyl-2-butenenitrile, and 4-amino-6-methyl-5-phenylpyrimidine. To investigate their significance, they were searched in data from seized amphetamine samples to determine to what extent they were present in illicitly produced amphetamine. Data of more than 580 cases from amphetamine profiling databases in Germany and the Netherlands were used for this purpose. These databases allowed analysis of the yearly occurrence of the markers going back to 2009. The markers revealed a trend that was in agreement with seizure reports and reflected an increasing use of APAAN from 2010 on. This paper presents experimental proof that APAAN is indeed the most important pre-precursor of amphetamine in recent years. It also illustrates how important it is to look for new ways to identify current trends in drug production since such trends can change within a few years.

Profiling ephedrine prepared from N-methylalanine via the Akabori-Momotani reaction.

Novel methods for synthesising methylamphetamine precursors are appearing in clandestine laboratories within Australia. One such laboratory involved the synthesis of ephedrine from N-methylalanine and benzaldehyde via the Akabori-Momotani reaction. This article presents chiral and stable isotope ratios of ephedrine synthesised via this method, along with a chemical profile of methylamphetamine produced from this ephedrine. Based on the chiral results and the δ13 C, δ15 N, and δ2 H values, it is possible to distinguish ephedrine made via the Akabori-Momotani reaction from ephedrine of a "natural", "semi-synthetic", or "fully-synthetic" origin. Methylamphetamine and ephedrine samples synthesised from benzaldehyde having an enriched δ2 H value (ie, > 0‰), via the Akabori-Momotani reaction, had an isotopic profile which set them apart from all other methylamphetamine samples. It was noted, however, that using stable isotope ratios alone to determine the precursor of methylamphetamine is limited; they could not with confidence differentiate between methylamphetamine and ephedrine synthesised from benzaldehyde having a depleted δ2 H value (ie, <0‰) from other ephedrine sources and phenyl-2-propanone based methylamphetamine samples profiled.

'APAAN in the neck' - A reflection on some novel impurities found in seized materials containing amphetamine in Ireland during routine forensic analysis.

This perspective examines amphetamine importations into Ireland. Some novel by-products were detected and linked to a change in the method of production of P2P from APAAN. These by-products remained present during subsequent Leuckart reaction conditions. Novel by-products from substituted cathinone synthesis reactions were also isolated and characterized.

Isolation and characterization of a newly identified impurity in methamphetamine synthesized via reductive amination of 1-phenyl-2-propanone (P2P) made from phenylacetic acid/lead (II) acetate.

A trace processing impurity found in certain methamphetamine exhibits was isolated and identified as trans-N-methyl-4-methyl-5-phenyl-4-penten-2-amine hydrochloride (1). It was determined that this impurity was produced via reductive amination of trans-4-methyl-5-phenyl-4-penten-2-one (4), which was one of a cluster of related ketones generated during the synthesis of 1-phenyl-2-propanone (P2P) from phenylacetic acid and lead (II) acetate. This two-step sequence resulted in methamphetamine containing elevated levels of 1. In contrast, methamphetamine produced from P2P made by other methods produced insignificant (ultra-trace or undetectable) amounts of 1. These results confirm that 1 is a synthetic marker compound for the phenylacetic acid and lead (II) acetate method. Analytical data for 1 and 4, and a postulated mechanism for the production of 4, are presented. Copyright © 2015 John Wiley & Sons, Ltd.

Organic impurity profiling of methylone and intermediate compounds synthesized from catechol.

This work examined the synthesis and organic impurity profile of methylone prepared from catechol. The primary aim of this work was to determine whether the synthetic pathway used to prepare 3,4-methylenedioxypropiophenone could be ascertained through analysis of the synthesized methylone. The secondary aim was the structural elucidation and origin determination of the organic impurities detected in methylone and the intermediate compounds. The organic impurities present in the reaction products were identified using GC-MS and NMR spectroscopy. Six organic impurities were detected in 1,3-benzodioxole and identified as the 1,3-benzodioxole dimer, 1,3-benzodioxole trimer, [1,3] dioxolo[4,5-b]oxanthrene, 4,4'-, 4,5'-, and 5,5'-methylenebis-1,3-benzodioxole. Six organic impurities were detected in 3,4-methylenedioxypropiophenone and identified as (2-hydroxyphenyl) propanoate, [2-(chloromethoxy) phenyl] propanoate, (2-propanoyloxyphenyl)propanoate, 5-[1-(1,3-benzodioxol-5-yl)prop-1-enyl]-1,3-benzodioxole, (5E)- and (5Z)-7-(1,3-benzodioxol-5-yl)-5-ethylidene-6-methyl-cyclopenta[f][1,3]benzodioxole). Exploratory synthetic experiments were also conducted to unambiguously identify the organic impurities detected in 3,4-methylenedioxypropiophenone. Two organic impurities were detected in 5-bromo-3,4-methylenedioxypropiophenone and identified as [2-(chloromethoxy)phenyl] propanoate and 3,4-methylenedioxypropiophenone. Five organic impurities were detected in methylone and identified as 3,4-methylenedioxypropiophenone, 1-(1,3-benzodioxol-5-yl)-N-methyl-propan-1-imine, 1-(1,3-benzodioxol-5-yl)-2-methylimino-propan-1-one, 1-(1,3-benzodioxol-5-yl)-N1,N2-dimethyl-propane-1,2-diimine and butylated hydroxytoluene. The origin of these organic impurities was also ascertained, providing valuable insight into the chemical profiles of methylone and the intermediate compounds. However, neither the catechol precursor nor the 1,3-benzodioxole intermediate could be identified based on the organic impurities detected in the synthesized methylone using standard techniques. This demonstrated that the organic impurity profiling of methylone had limitations in the determination of precursor chemical and synthetic pathways used. Copyright © 2017 John Wiley & Sons, Ltd.

Forensic analysis of P2P derived amphetamine synthesis impurities: identification and characterization of indene by-products.

1-Phenyl-2-propanone (P2P) is an internationally monitored precursor that has become increasingly difficult for illicit amphetamine producers to source, which means that alternative routes to its preparation have become increasingly important. One such approach includes the hydrolysis of alpha-phenylacetoacetonitrile (APAAN) with sulfuric acid. Previously, we reported the identification of 4,6-dimethyl-3,5-diphenylpryid-2-one following implementation of hydrolysis conditions and it was proposed that this compound might serve as one route specific by-product in the APAAN to P2P conversion. This study continued to explore the presence of impurities formed during this conversion and expanded also into a second route of P2P synthesis starting from alpha-methylstyrene (AMS). All P2P products underwent the Leuckart procedure to probe the presence of P2P-related impurities that might have carried through to the final product. Two by-products associated with the APAAN hydrolysis route to P2P were identified as 2,3-diacetyl-2,3-diphenylsuccinonitrile (1) and 2-methyl-1-phenyl-1,3-dicarbonitrile-1H-indene (2), respectively. Two by-products associated with the AMS route to P2P and subsequent Leuckart reaction were 1,1,3-trimethyl-3-phenyl-2,3-dihydro-1H-indene (3) and 1-phenyl-N-(phenylethyl)propan-2-amine (4), respectively. The two indenes (2 and 3) identified in synthesized amphetamine originating from P2P suggested that it might be possible to differentiate between the two synthetic routes regarding the use of APAAN and AMS. Furthermore, the association of these compounds with amphetamine production appears to have been reported for the first time. The presence of compounds 1 - 4 in seized amphetamine samples and waste products could facilitate the suggestion whether APAAN or AMS were employed in the synthesis route to the P2P. Copyright © 2016 John Wiley & Sons, Ltd.

Essential/precursor chemicals and drug consumption: impacts of US sodium permanganate and Mexico pseudoephedrine controls on the numbers of US cocaine and methamphetamine users.

BACKGROUND AND AIMS: In December 2006 the United States regulated sodium permanganate, a cocaine essential chemical. In March 2007 Mexico, the United States' primary source for methamphetamine, closed a chemical company accused of illicitly importing 60+ tons of pseudoephedrine, a methamphetamine precursor chemical. US cocaine availability and methamphetamine availability, respectively, decreased in association. This study tested whether the controls had impacts upon the numbers of US cocaine users and methamphetamine users. DESIGN: Auto-regressive integrated moving average (ARIMA) intervention time-series analysis. Comparison series-heroin and marijuana users-were used. SETTING: United States, 2002-14. PARTICIPANTS: The National Survey on Drug Use and Health (n = 723 283), a complex sample survey of the US civilian, non-institutionalized population. MEASUREMENTS: Estimates of the numbers of (1) past-year users and (2) past-month users were constructed for each calendar quarter from 2002 to 2014, providing each series with 52 time-periods. FINDINGS: Downward shifts in cocaine users started at the time of the cocaine regulation. Past-year and past-month cocaine users series levels decreased by approximately 1 946 271 (-32%) (P < 0.05) and 694 770 (-29%) (P < 0.01), respectively-no apparent recovery occurred through 2014. Downward shifts in methamphetamine users started at the time of the chemical company closure. Past-year and past-month methamphetamine series levels decreased by 494 440 (-35%) [P < 0.01; 95% confidence interval (CI) = -771 897, -216 982] and 277 380 (-45%) (P < 0.05; CI = -554 073, -686), respectively-partial recovery possibly occurred in 2013. The comparison series changed little at the intervention times. CONCLUSIONS: Essential/precursor chemical controls in the United States (2006) and Mexico (2007) were associated with large, extended (7+ years) reductions in cocaine users and methamphetamine users in the United States.

The synthesis and investigation of impurities found in Clandestine Laboratories: Baeyer-Villiger Route Part I; Synthesis of P2P from benzaldehyde and methyl ethyl ketone.

The synthesis of impurities detected in clandestinely manufactured Amphetamine Type Stimulants (ATS) has emerged as more desirable than simple "fingerprint" profiling. We have been investigating the impurities formed when phenyl-2-propanone (P2P) 5, a key ATS precursor, is synthesised in three steps; an aldol condensation of benzaldehyde and methyl ethyl ketone (MEK); a Baeyer-Villiger reaction; and ester hydrolysis. We have identified and selectively synthesised several impurities that may be used as route specific markers for this series of synthetic steps. Specifically these impurities are 3-methyl-4-phenyl-3-buten-2-one 3, 2-methyl-1,5-diphenylpenta-1,4-diene-3-one 9, 2-(methylamino)-3-methyl-4-phenyl-3-butene 16, 2-(Methylamino)-3-methyl-4-phenylbutane 17, and 1-(methylamino)-2-methyl-1,5-diphenylpenta-4-ene-3-one 22.