General chemical structure of substituted benzofurans
The substituted benzofurans are a class of chemical compounds based on the heterocyclic and polycyclic compound benzofuran. Many medicines use the benzofuran core as a scaffold,[1][2][3] 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 (at any position), and combined with a range of other substituents.[4][5][6][7] Some psychoactive derivatives from this family have been sold under the name Benzofury.[8]
Substituted benzofurans saw widespread use as recreational drugs by being sold as research chemicals making them exempt from drug legislation. Many of the more common compounds were banned in the UK in June 2013 as temporary class drugs, while others have been made permanently illegal in various jurisdictions.[34][35][36]
List of substituted benzofurans
The derivatives may be produced by substitutions at six locations of the benzofuran molecule, as well as saturation of the 2,3- double bond.
↑"Pharmacokinetics, pharmacodynamics and toxicology of new psychoactive substances (NPS): 2C-B, 4-fluoroamphetamine and benzofurans". Drug and Alcohol Dependence157: 18–27. December 2015. doi:10.1016/j.drugalcdep.2015.10.011. PMID26530501.
↑"Identification of five substituted phenethylamine derivatives 5-MAPDB, 5-AEDB, MDMA methylene homolog, 6-Br-MDMA, and 5-APB-NBOMe". Drug Testing and Analysis9 (2): 199–207. February 2017. doi:10.1002/dta.1955. PMID26856255.
↑"Pharmacology and Literature Review Based on Related Death and Non-Fatal Case Reports of the Benzofurans and Benzodifurans Designer Drugs". Current Pharmaceutical Design23 (36): 5523–5529. 2017. doi:10.2174/1381612823666170714155140. PMID28714411.
↑ 13.013.113.213.3Greene, Shaun L (2013). "Benzofurans and Benzodifurans". Novel Psychoactive Substances. Elsevier. p. 383–392. doi:10.1016/b978-0-12-415816-0.00016-x. ISBN978-0-12-415816-0. https://linkinghub.elsevier.com/retrieve/pii/B978012415816000016X. Retrieved 2 November 2025. "A patent granted to Eli Lilly and Company in 2006 classifies 5-APB and 6-APB as 5HT2C receptor agonists [15]. [...] Internet user reports of 5-APB and 6-APB date from late 2010 [13]. [...] Information regarding the desired clinical effects of 5-APB and 6-APB is limited to on-line user report forums. Limited user reports indicate that positive effects of 5-APB include increased empathy, variable euphoria, visual disturbances, appreciation for music and dancing and more general ‘stimulation’ as opposed to 6-APB [12,23–25]. Reported positive effects of 6-APB include increased tactile and visual stimulation, mild euphoria, and appreciation for music, visual hallucinations and increase in mood, feelings of peace, love and self-acceptance [10,11,13,14]."
↑ 14.014.114.214.314.414.514.614.714.8"The psychoactive aminoalkylbenzofuran derivatives, 5-APB and 6-APB, mimic the effects of 3,4-methylenedioxyamphetamine (MDA) on monoamine transmission in male rats". Psychopharmacology (Berl)237 (12): 3703–3714. December 2020. doi:10.1007/s00213-020-05648-z. PMID32875347. "The synthetic preparation of both 5-APB and 6-APB was first published in 2000 as part of a research program designed for the development of selective 5-HT2C receptor agonists (Briner et al. 2000; Briner et al. 2006) [...] Briner K, Burkhart JP, Burkholder TP, Fisher MJ, Gritton WH, Kohlman DT, Liang SX, Miller SC, Mullaney JT, Xu Y-C, Xu Y (2000) Aminoalkylbenzofurans as serotonin (5-HT(2C)) agonists Patent No. WO2000044737A1, Eli Lilly and Company, Indianapolis, IN, USA, 2000. Briner K, Burkhart JP, Burkholder TP, Fisher MJ, Gritton WH, Kohlman DT, Liang SX, Miller SC, Mullaney JT, Xu YC (2006) Aminoalkylbenzofurans as serotonin (5-HT(2C)) agonists Patent No. US7045545B1, Eli Lilly and Company, Indianapolis, IN, USA, 2006.".
↑"The effects of non-medically used psychoactive drugs on monoamine neurotransmission in rat brain". European Journal of Pharmacology559 (2–3): 132–137. March 2007. doi:10.1016/j.ejphar.2006.11.075. PMID17223101.
↑ 29.029.129.2Matthew Baggott, "Advantageous benzofuran compositions for mental disorders or enhancement", US patent 20230150963, published 2023 May 18, assigned to Tactogen
↑"Synthesis and pharmacological examination of benzofuran, indan, and tetralin analogues of 3,4-(methylenedioxy)amphetamine". J Med Chem36 (23): 3700–3706. November 1993. doi:10.1021/jm00075a027. PMID8246240.
↑"The effects of benzofury (5-APB) on the dopamine transporter and 5-HT2-dependent vasoconstriction in the rat". Prog Neuropsychopharmacol Biol Psychiatry48: 57–63. January 2014. doi:10.1016/j.pnpbp.2013.08.013. PMID24012617.
↑"Benzofuran bioisosteres of hallucinogenic tryptamines". Journal of Medicinal Chemistry35 (11): 2061–4. May 1992. doi:10.1021/jm00089a017. PMID1534585.
↑"Synthesis and pharmacological examination of benzofuran, indan, and tetralin analogues of 3,4-(methylenedioxy)amphetamine". Journal of Medicinal Chemistry36 (23): 3700–6. November 1993. doi:10.1021/jm00075a027. PMID8246240.
↑Karin Briner, Joseph Paul Burkhart, Timothy Paul Burkholder, Matthew Joseph Fisher, William Harlan Gritton, Daniel Timothy Kohlman, Sidney Xi Liang, Shawn Christopher Miller, Jeffrey Thomas Mullaney, Yao-Chang Xu, Yanping Xu, "Aminoalkylbenzofurans as serotonin (5-HT(2c)) agonists", US patent 7045545, published 19 January 2000, issued 16 May 2006
↑"Identification of (2-aminopropyl)benzofuran (APB) phenyl ring positional isomers in internet purchased products". Drug Testing and Analysis5 (4): 270–6. April 2013. doi:10.1002/dta.1451. PMID23349125.
↑"Synthesis and evaluation of 2,3-dihydrobenzofuran analogues of the hallucinogen 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane: drug discrimination studies in rats". Journal of Medicinal Chemistry29 (2): 302–4. February 1986. doi:10.1021/jm00152a022. PMID3950910.
↑"2,3-Dihydrobenzofuran analogues of hallucinogenic phenethylamines". Journal of Medicinal Chemistry34 (1): 276–81. January 1991. doi:10.1021/jm00105a043. PMID1992127.
↑"Dihydrobenzofuran analogues of hallucinogens. 3. Models of 4-substituted (2,5-dimethoxyphenyl)alkylamine derivatives with rigidified methoxy groups". Journal of Medicinal Chemistry39 (15): 2953–61. July 1996. doi:10.1021/jm960199j. PMID8709129.
↑"Identification of five substituted phenethylamine derivatives 5-MAPDB, 5-AEDB, MDMA methylene homolog, 6-Br-MDMA, and 5-APB-NBOMe". Drug Testing and Analysis9 (2): 199–207. February 2017. doi:10.1002/dta.1955. PMID26856255.
↑"Phenethylamine-derived new psychoactive substances 2C-E-FLY, 2C-EF-FLY, and 2C-T-7-FLY: Investigations on their metabolic fate including isoenzyme activities and their toxicological detectability in urine screenings". Drug Testing and Analysis11 (10): 1507–1521. October 2019. doi:10.1002/dta.2675. PMID31299701.