Analogs of alpha-methylphenethylamine (amphetamine). I. Synthesis and pharmacological activity of some methoxy and/or methyl analogs

Entactogens: How the Name for a Novel Class of Psychoactive Agents Originated

At first glance, it appears there is little difference between the molecular structures of methylenedioxymethamphetamine (MDMA), which has an N-methyl attached to its amino group, and methylenedioxyamphetamine (MDA), a primary amine that is recognized to have hallucinogenic activity. It is known from studies with other hallucinogenic amphetamines that N-methylation of hallucinogenic amphetamines attenuates or abolishes hallucinogenic activity. Nevertheless, MDMA is biologically active and has a potency only slightly less than its MDA parent. Importantly, it is the Ievo-isomer of hallucinogenic phenethylamines that is more biologically active, whereas it is the dextro isomer of MDMA that is more active. This reversal of stereochemistry for the activity of two very closely related molecules is a very powerful clue that their mechanisms of action differ. Finally, extension of the alpha-methyl of hallucinogenic amphetamines to an alpha-ethyl moiety completely abolishes their hallucinogenic activity. Ultimately, we extended the alpha-methyl group of MDMA to an alpha-ethyl to afford a molecule we named (N-Methyl-1-(1,3-benzodioxol-5-yl)-2-butanamine (MBDB) that retained significant MDMA-like psychoactivity. Hence, there are three structural features that distinguish MDMA from the hallucinogenic amphetamines: (1) the N-methyl on the basic nitrogen, (2) the reversal of stereochemistry and, (3) tolerance of an alpha-ethyl moiety as contrasted with the alpha-methyl of hallucinogenic phenethylamines. Clearly, MDMA is distinct from classical hallucinogenic phenethylamines in its structure, and its psychopharmacology is also unique. Thus, in 1986 I proposed the name "Entactogen" for the pharmacological class of drugs that includes 3,4-methylenedioxymethamphetamine (MDMA) and other substances with a similar psychopharmacological effect. The name is derived from roots that indicate that entactogens produce a "touching within." Rather than having significant psychostimulant, or hallucinogenic effects, MDMA powerfully promotes affiliative social behavior, has acute anxiolytic effects, and can lead to profound states of introspection and personal reflection. Its mechanism of action is now established as involving transport of MDMA by the neuronal serotonin reuptake carrier followed by carrier-mediated release of stored neuronal serotonin.

Arylethylamine psychotropic recreational drugs: a chemical perspective

The arylethylamines substituted in the aryl ring, side-chain carbons and on the terminal amine, comprise a large number of human mood and behaviour altering chemicals. Some of these psychotropic drugs have been used since pre-history, but in many states are proscribed and are consequently subject to clandestine synthesis and illegal traffic world-wide in the forms particularly of amphetamines and to a lesser extent tryptamines. The chemistry employed in the synthesis of these compounds is dictated often by the available precursors and relies usually on relatively simple, unsophisticated conversion reactions to a suitable product. The internet web sites and documentation of the recreational drug culture have been studied alongside the professional scientific and regulatory literature. The review demonstrates the great complexity of the chemistry and neuro-pharmacology of these chemicals and the challenge faced by legislative bodies to control their traffic and use for the sake of social welfare.

A formal total synthesis of (+/-)-cephalotaxine using sequential N-acyliminium ion reactions

[reaction: see text] Novel synthesis of cephalotaxine 1 based on tertiary N-acyliminium ion chemistry starting from alkynylamide 2 was achieved. The key steps include the preparation of pyrroloisoquinoline 4 from alkynylamide 2, the ring expansion of pyrroloisoquinoline 4 to pyrrolobenzazepine 12, and the construction of cyclopentapyrrolobenzazepine ring system 6, all of which are derived from N-acyliminium ion intermediates.

Comparison of behavioral properties of di- and tri-methoxyphenylisopropylamines

Prominent among the class of hallucinogenic phenylisopropylamines is the 2,5-dimethoxy substitution pattern; this pattern has long been recognized as being an important feature of the more potent agents within this class. The purpose of this present study was to explore the behavioral properties of a series of methoxylated phenylisopropylamines in order to determine the effect of other substitution patterns and the relative importance of individual methoxy groups. Rats, trained to discriminate the hallucinogenic agent 2,5-dimethoxy-4-methyl-phenylisopropylamine (DOM) from saline in a two-lever drug discrimination task, were challenged with a series of di- and trimethoxyphenylisopropylamines (i.e., DMA and TMA derivatives). DOM-stimulus generalization was found to occur with 2,4-DMA but not with 2,3-DMA, 2.6-DMA, or 3,5-DMA; generalization also occurred with 2,3,4-TMA, 2,3,5-TMA, 2,4,6-TMA and 3,4,5-TMA. The 2,4-dimethoxy pattern also emerges as an important feature among the more active agents.