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Formula | C11H13NO |
Molar mass | 175.231 g·mol−1 |
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6-APB (6-(2-aminopropyl)benzofuran) is an empathogenic psychoactive compound of the substituted benzofuran and substituted phenethylamine classes. [1] 6-APB and other compounds are sometimes informally called "Benzofury" in newspaper reports. It is similar in structure to MDA, but differs in that the 3,4-methylenedioxyphenyl ring system has been replaced with a benzofuran ring. 6-APB is also the unsaturated benzofuran derivative of 6-APDB. It may appear as a tan grainy powder.
While the drug never became particularly popular, it briefly entered the rave and underground clubbing scene in the UK before its sale and import were banned. It falls under the category of research chemicals, sometimes called "legal highs." Because 6-APB and other substituted benzofurans have not been explicitly outlawed in some countries, they are often technically legal, contributing to their popularity.
6-APB is a serotonin–norepinephrine–dopamine reuptake inhibitor (SNDRI) with Ki values of 117, 150, and 2698 nM for the norepinephrine transporter (NET), dopamine transporter (DAT), and serotonin transporter (SERT), respectively. [1] In addition, 6-APB not only blocks the reuptake of these monoamine neurotransmitters but is also a releasing agent of them; that is, it is a serotonin-norepinephrine-dopamine releasing agent (SNDRA). [2] In addition to actions at the monoamine transporters, 6-APB is a potent full agonist of the serotonin 5-HT2B receptor (Ki = 3.7 nM), [1] with higher affinity for this target than any other site. [3] Moreover, unlike MDMA, 6-APB shows 100-fold selectivity for the 5-HT2B receptor over the 5-HT2A and 5-HT2C receptors. [3] [4] It is notably both more potent and more selective as an agonist of the 5-HT2B receptor than the reference 5-HT2B receptor agonist, BW-723C86, which is commonly used for research into the 5-HT2B receptor.[ citation needed ] Aside from the 5-HT2B receptor, 6-APB has also been found to bind with high affinity to the α2C-adrenergic receptor subtype (Ki = 45 nM), although the clinical significance of this action is unknown. [1] 6-APB showed little other affinity at a wide selection of other sites. [1]
The potent agonism of the 5-HT2B receptor makes it likely that 6-APB would be cardiotoxic with chronic or long-term use, as seen with other 5-HT2B receptor agonists such as the withdrawn serotonergic anorectic fenfluramine. [1] [5]
The pharmacokinetics of 6-APB have not been studied, however, some information can be extracted from user reports. These suggest a slow onset of 40–120 minutes. The drugs peak effects last 7 hours, followed by a comedown phase of approximately 2 hours, and after effects for up to 24 hours. [6]
Although limited literature is available, there is some data on metabolism of 6-APB in rats. Its Phase I metabolism involves hydroxylation of the furan ring, then cleavage of the ring, followed by a reduction of the unsaturated aldehyde from the previous step. The resulting aldehyde may then take two paths. It is either oxidized to a carboxylic acid or reduced to an alcohol, and then hydroxylated. Phase II metabolism consists of glucuronidation. The most prevalent metabolites in rats were 3-carboxymethyl-4-hydroxyamphetamine and 4-carboxymethyl-3-hydroxyamphetamine. [7]
Acute psychosis has been associated with recreational use of 6-APB in combination with the synthetic cannabinoid JWH-122. [8]
6-APB and its structural isomer 5-APB have been tested with a series of agents including: Marquis, Liebermann, Mecke, and Froehde reagents. [9] Exposing compounds to the reagents gives a colour change which is indicative of the compound under test.
Compound | Marquis | Mecke | Mandelin | Liebermann | Froehde | Gallic | Ehrlich | Hofmann | Simon's | Folin |
---|---|---|---|---|---|---|---|---|---|---|
6-APB | Purple | Purple to black | Purple to black | Black | Purple | Brown | Orange | Light orange | No reaction | Light orange |
6-APB succinate | Purple | Purple to black | Purple to black | Black | Purple | Brown | Faint orange | No reaction | No reaction | Light orange |
6-APB succinate is reported to be practically insoluble in CHCl3 as well as very minimally soluble in cold water. A batch seized by the DEA contained a 2:1 ratio of succinate to 6-APB. [10]
The synthesis by Briner et al. [4] entailed refluxing 3-bromophenol with bromoacetaldehyde diethylacetal and sodium hydride to give the diethyl acetal, which then was heated with polyphosphoric acid to give a mixture of bromobenzofuran structural isomers: 4-bromo-1-benzofuran and 6-bromo-1-benzofuran. The isomers were separated by silica gel column chromatography, then converted to their respective propanone derivatives, and then reductively aminated to give 6-APB and 4-APB, both of which were converted to their HCl ion pairs for further examination.
6-APB can be found in freebase, hydrochloride, and succinate form. The freebase is purportedly 20% stronger than the hydrochloride salt and 65% stronger than the succinate. This means 100 mg of 6-APB HCl is equivalent to 83 mg of 6-APB freebase and 100 mg of 6-APB succinate is equivalent to 60 mg of 6-APB freebase. Different production batches may have impurities and should be treated with care.
Based on anecdotal reports, the dosages for 6-APB hydrochloride are the following:
Oral | |
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Threshold | 15 mg |
Light | 15 – 60 mg |
Common | 60 – 90 mg |
Strong | 90 – 120 mg |
Heavy | 120 mg + |
Oral | |
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Onset | 30 – 60 minutes (or more) |
Come up | 60 – 120 minutes |
Peak | 3 – 4 hours |
Offset | 2 – 3 hours |
Total | 7 – 10 hours |
After effects | 6 – 48 hours |
Dosage for Freebase or Succinates have to be adjusted accordingly.
In 1999, amphetamines were changed from Schedule III to Schedule I as a result of the Safe Streets Act. Some have speculated that 6-APB's structure qualifies it as a Schedule I drug as an analog of MDA. [11] [ unreliable source? ]
In 2014, a study funded by the Canadian Institutes of Health Research noted that 6-APB "may or may not be legal in Canada depending on how one interprets the current Act" [12] and that it could be purchased for academic purposes without an exemption from Health Canada. The study also noted how, unlike the MDMA it often serves as a replacement for in countries like the US, 6-APB's benzofuran structure does not make it a direct analogue of amphetamine despite similarities in effects.
6-APB is not scheduled at the federal level in the United States, [13] [ failed verification ] but it may be considered an analog of amphetamine, in which case purchase, sale, or possession could be prosecuted under the Federal Analog Act. [14]
6-APB is scheduled in government decree on narcotic substances, preparations and plants and hence is illegal. [15]
6-APB is illegal in Germany since the 17th of July, 2013, when it was added to Anlage II of the Betäubungsmittelgesetz.
In Luxembourg, 6-APB is not cited in the list of prohibited substances. [18] Therefore, it is still a legal substance.
6-APB is not listed under the Opium Law or the Medicine Act in the Netherlands, and thus currently legal.
Certain countries contain a "substantially similar" catch-all clause in their drug law, such as New Zealand and Australia. This includes 6-APB as it is similar in chemical structure to the class A drug MDA, meaning 6-APB may be viewed as a controlled substance analogue in these jurisdictions. [19]
In Sweden, as of 27 December 2009 6-APB is classified as "health hazard" under the act Lagen om förbud mot vissa hälsofarliga varor (translated Act on the Prohibition of Certain Goods Dangerous to Health). [20]
On June 10, 2013 6-APB and a number of analogues were classified as Temporary Class Drugs in the UK following an ACMD recommendation. [5] This means that sale and import of the named substances are criminal offences and are treated as for class B drugs. [21] On November 28, 2013 the ACMD recommended that 6-APB and related benzofurans should become Class B, Schedule 1 substances. [5] On March 5, 2014 the UK Home Office announced that 6-APB would be made a class B drug on 10 June 2014 alongside every other benzofuran entactogen and many structurally related drugs. [22]
6-APB has been a controlled substance in China since 1 July 2024 [23]
α-Methyltryptamine is a psychedelic, stimulant, and entactogen drug of the tryptamine class. It was originally developed as an antidepressant by chemists at Upjohn in the 1960s, and was used briefly as an antidepressant in Russia under the trade name Indopan before being discontinued.
Methcathinone is a monoamine alkaloid and psychoactive stimulant, a substituted cathinone. It is used as a recreational drug due to its potent stimulant and euphoric effects and is considered to be addictive, with both physical and psychological withdrawal occurring if its use is discontinued after prolonged or high-dosage administration. It is usually snorted, but can be smoked, injected, or taken orally.
3,4-Methylenedioxyamphetamine is an empathogen-entactogen, psychostimulant, and psychedelic drug of the amphetamine family that is encountered mainly as a recreational drug. In its pharmacology, MDA is a serotonin–norepinephrine–dopamine releasing agent (SNDRA). In most countries, the drug is a controlled substance and its possession and sale are illegal.
2,5-Dimethoxy-4-iodoamphetamine (DOI) is a psychedelic drug and a substituted amphetamine. Unlike many other substituted amphetamines, however, it is not primarily a stimulant. DOI has a stereocenter and R-(−)-DOI is the more active stereoisomer. In neuroscience research, [125I]-R-(−)-DOI is used as a radioligand and indicator of the presence of 5-HT2A serotonin receptors. DOI's effects have been compared to LSD, although there are differences that experienced users can distinguish. Besides the longer duration, the trip tends to be more energetic than an LSD trip, with more body load and a different subjective visual experience. The after effects include residual stimulation and difficulty sleeping, which, depending on the dose, may persist for days. While rare, it is sometimes sold as a substitute for LSD, or even sold falsely as LSD, which may be dangerous because DOI does not have the same established safety profile as LSD.
5-(2-Aminopropyl)-2,3-dihydro-1H-indene (5-APDI), also known as indanylaminopropane (IAP), IAP (psychedelic), 2-API(2-aminopropylindane), indanametamine, and, incorrectly, as indanylamphetamine, is an entactogen and psychedelic drug of the amphetamine family. It has been sold by online vendors through the Internet and has been encountered as a designer drug since 2003, but its popularity and availability has diminished in recent years.
Naphthylaminopropane (PAL-287) is an experimental drug under investigation as of 2007 for the treatment of alcohol and stimulant addiction.
(–)-Benzofuranylpropylaminopentane is an experimental drug related to selegiline which acts as a monoaminergic activity enhancer (MAE). It is orally active in animals.
5-(2-Aminopropyl)-2,3-dihydrobenzofuran is a putative entactogen drug of the phenethylamine and amphetamine classes. It is an analogue of MDA where the heterocyclic 3-position oxygen from the 3,4-methylenedioxy ring has been replaced by a methylene bridge. 6-APDB is an analogue of 5-APDB where the 4-position oxygen has been replaced by a methylene bridge instead. 5-APDB was developed by a team led by David E. Nichols at Purdue University as part of their research into non-neurotoxic analogues of MDMA.
A monoamine releasing agent (MRA), or simply monoamine releaser, is a drug that induces the release of a monoamine neurotransmitter from the presynaptic neuron into the synapse, leading to an increase in the extracellular concentrations of the neurotransmitter. Many drugs induce their effects in the body and/or brain via the release of monoamine neurotransmitters, e.g., trace amines, many substituted amphetamines, and related compounds.
A serotonin releasing agent (SRA) is a type of drug that induces the release of serotonin into the neuronal synaptic cleft. A selective serotonin releasing agent (SSRA) is an SRA with less significant or no efficacy in producing neurotransmitter efflux at other types of monoamine neurons.
5-(2-Aminopropyl)indole is an indole and phenethylamine derivative with empathogenic effects. Its preparation was first reported by Albert Hofmann in 1962. It is a designer drug that has been openly sold as a recreational drug by online vendors since 2011.
Serotonin antagonist and reuptake inhibitors (SARIs) are a class of drugs used mainly as antidepressants, but also as anxiolytics and hypnotics. They act by antagonizing serotonin receptors such as 5-HT2A and inhibiting the reuptake of serotonin, norepinephrine, and/or dopamine. Additionally, most also antagonize α1-adrenergic receptors. The majority of the currently marketed SARIs belong to the phenylpiperazine class of compounds.
6-(2-Aminopropyl)-2,3-dihydrobenzofuran is a stimulant and entactogen drug of the phenethylamine and amphetamine classes. It is an analogue of MDA where the heterocyclic 4-position oxygen from the 3,4-methylenedioxy ring has been replaced with a methylene bridge. 5-APDB (3-Desoxy-MDA) is an analogue of 6-APDB where the 3-position oxygen has been replaced with a methylene instead. 6-APDB, along with 5-APDB, was first synthesized by David E. Nichols in the early 1990s while investigating non-neurotoxic MDMA analogues.
5-APB is an empathogenic psychoactive compound of the substituted benzofuran, substituted amphetamine and substituted phenethylamine classes. 5-APB and other compounds are sometimes informally called "Benzofury".
A monoamine reuptake inhibitor (MRI) is a drug that acts as a reuptake inhibitor of one or more of the three major monoamine neurotransmitters serotonin, norepinephrine, and dopamine by blocking the action of one or more of the respective monoamine transporters (MATs), which include the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT). This in turn results in an increase in the synaptic concentrations of one or more of these neurotransmitters and therefore an increase in monoaminergic neurotransmission.
5-MAPB is an entactogenic designer drug similar to MDMA in its structure and effects.
5-EAPB is a potentially entactogenic amphetamine which is structurally related to 5-MAPB and 5-APB. It might be predicted to show similar effects to these drugs in humans, but the pharmacology of 5-EAPB remains unstudied as of 2020.
5-MAPDB (1-(2,3-dihydrobenzofuran-5-yl)-N-methylpropan-2-amine) is a chemical compound which acts as an entactogenic drug. It is structurally related to drugs like 5-APDB and 5-MAPB, which have similar effects to MDMA and have been used as recreational drugs. 5-MAPDB has been studied to determine its pharmacological activity, and was found to be a relatively selective serotonin releaser, though with weaker actions as a releaser of other monoamines and 5-HT2 receptor family agonist, similar to older compounds such as 5-APDB.
Substituted phenylmorpholines, or substituted phenmetrazines alternatively, are chemical derivatives of phenylmorpholine or of the psychostimulant drug phenmetrazine. Most such compounds act as releasers of monoamine neurotransmitters, and have stimulant effects. Some also act as agonists at serotonin receptors, and compounds with an N-propyl substitution act as dopamine receptor agonists. A number of derivatives from this class have been investigated for medical applications, such as for use as anorectics or medications for the treatment of ADHD. Some compounds have also become subject to illicit use as designer drugs.
The substituted benzofurans are a class of chemical compounds based on the heterocyclyc and polycyclic compound benzofuran. Many medicines use the benzofuran core as a scaffold, but most commonly the term is used to refer to the simpler compounds in this class which include numerous psychoactive drugs, including stimulants, psychedelics and empathogens. In general, these compounds have a benzofuran core to which a 2-aminoethyl group is attached, and combined with a range of other substituents. Some psychoactive derivatives from this family have been sold under the name Benzofury.