Substituted phenethylamines (or simply phenethylamines) are a
chemical class
Chemical classification systems attempt to classify elements or compounds according to certain chemical functional or structural properties. Whereas the structural properties are largely intrinsic, functional properties and the derived classi ...
of
organic compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...
s that are based upon the
phenethylamine
Phenethylamine (PEA) is an organic compound, natural monoamine alkaloid, and trace amine, which acts as a central nervous system stimulant in humans. In the brain, phenethylamine regulates monoamine neurotransmission by binding to trace ami ...
structure; the class is composed of all the
derivative
In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...
compounds of phenethylamine which can be formed by replacing, or
substituting, one or more
hydrogen atom
A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral hydrogen atom contains a single positively charged proton in the nucleus, and a single negatively charged electron bound to the nucleus by the Coulomb for ...
s in the phenethylamine core structure with
substituent
In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule.
The suffix ''-yl'' is used when naming organic compounds that contain a single bond r ...
s. Phenylethylamines are also generally found to be
central nervous system stimulants with many also being entactogens/empathogens, and hallucinogens.
Structural classification

The
structural formula of any substituted phenethylamine contains a
phenyl ring that is joined to an
amino (NH) group via a two-carbon
sidechain. Hence, any substituted phenethylamine can be classified according to the substitution of
hydrogen (H) atoms on phenethylamine's phenyl ring, sidechain, or amino group with a
specific group of atoms. Several classes of substances can be considered phenylethylamine derivatives such as
Substituted amphetamines, where there is a
methyl
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula (whereas normal methane has the formula ). In formulas, the group is often abbreviated as ...
group substituted at the alpha position on the ethyl chain,
Substituted methylenedioxyphenethylamines, where a
methylenedioxy group is joined at the 3 and 4 positions on the phenyl ring, and
Substituted cathinones, which have a carbonyl group substituted at the beta position on the ethyl chain, most of which also have a methyl group substituted at the alpha positioning making most cathinones substituted amphetamines as well.
Pharmacology
Most substituted phenethylamines are
psychoactive drug
A psychoactive drug, psychopharmaceutical, mind-altering drug, consciousness-altering drug, psychoactive substance, or psychotropic substance is a chemical substance that alters psychological functioning by modulating central nervous system acti ...
s which belong to a variety of different
drug class
A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via inhalation, injection, smoking, ingestio ...
es, including
central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...
stimulant
Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognition, ...
s (e.g.,
amphetamine
Amphetamine (contracted from Alpha and beta carbon, alpha-methylphenethylamine, methylphenethylamine) is a central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, an ...
),
hallucinogen
Hallucinogens, also known as psychedelics, entheogens, or historically as psychotomimetics, are a large and diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, mo ...
s (e.g.,
3,4,5-trimethoxyphenethylamine a.k.a. mescaline),
2,5-dimethoxy-4-methylamphetamine DOM),
entactogen
Entactogens, also known as empathogens or connectogens, are a class of psychoactive drugs that induce the production of experiences of emotional communion, oneness, connectedness, emotional openness—that is, empathy—as particularly observe ...
(e.g. MDA),
appetite suppressant
An anorectic is a drug that reduces appetite, resulting in lower food consumption, leading to weight loss. These substances work by affecting the central nervous system or certain neurotransmitters to create a feeling of fullness or reduce the desi ...
s (e.g.
phentermine
Phentermine, sold under the brand name Adipex-P among others, is a medication used together with diet and exercise to treat obesity. It is available by itself or as the combination phentermine/topiramate. Phentermine is taken by mouth.
Com ...
),
nasal decongestants and
bronchodilator
A bronchodilator or broncholytic (although the latter occasionally includes secretory inhibition as well) is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lun ...
s (e.g.,
levomethamphetamine
Levomethamphetamine (International Nonproprietary Name, INN: levmetamfetamine) is an optical isomer of methamphetamine primarily used as a Topical decongestant, topical nasal decongestant. Levomethamphetamine is used to treat nasal congestion f ...
and
pseudoephedrine),
antidepressant
Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction.
Common side effects of antidepressants include Xerostomia, dry mouth, weight gain, dizziness, headaches, akathi ...
s (e.g.
bupropion and
phenelzine
Phenelzine, sold under the brand name Nardil among others, is a non-selective and irreversible monoamine oxidase inhibitor (MAOI) of the hydrazine family which is primarily used as an antidepressant and anxiolytic to treat depression and a ...
),
antiparkinson agents (e.g.,
selegiline
Selegiline, also known as L-deprenyl and sold under the brand names Eldepryl, Zelapar, and Emsam among others, is a medication which is used in the treatment of Parkinson's disease and major depressive disorder. It has also been studied and us ...
), and
vasopressors (e.g.,
ephedrine
Ephedrine is a central nervous system (CNS) stimulant and sympathomimetic agent that is often used to prevent hypotension, low blood pressure during anesthesia. It has also been used for asthma, narcolepsy, and obesity but is not the preferred ...
), among others.
Many of these psychoactive compounds exert their pharmacological effects primarily by modulating
monoamine neurotransmitter
Monoamine neurotransmitters are neurotransmitters and neuromodulators that contain one amino group connected to an aromatic ring by a two-carbon chain (such as -CH2-CH2-). Examples are dopamine, norepinephrine and serotonin.
All monoamines ...
systems; however, there is no known
mechanism of action
In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical Drug interaction, interaction through which a Medication, drug substance produces its pharmacological effect. A mechanism of action usually includes mention o ...
or
biological target
A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets ...
that is common to all members of this subclass.
Examples
Numerous
endogenous
Endogeny, in biology, refers to the property of originating or developing from within an organism, tissue, or cell.
For example, ''endogenous substances'', and ''endogenous processes'' are those that originate within a living system (e.g. an ...
compounds – including
hormone
A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...
s,
catecholamine
A catecholamine (; abbreviated CA), most typically a 3,4-dihydroxyphenethylamine, is a monoamine neurotransmitter, an organic compound that has a catechol (benzene with two hydroxyl side groups next to each other) and a side-chain amine.
Cate ...
s such as
dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized ...
and
noradrenaline
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as a hormone, neurotransmitter and neuromodulator. The name "noradrenaline" (from ...
, and many
trace amine
Trace amines are an endogenous group of trace amine-associated receptor 1 (TAAR1) agonists – and hence, monoaminergic neuromodulators – that are structurally and metabolically related to classical monoamine neurotransmitters. Compared to ...
s (e.g.
adrenaline
Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands a ...
,
phenethylamine
Phenethylamine (PEA) is an organic compound, natural monoamine alkaloid, and trace amine, which acts as a central nervous system stimulant in humans. In the brain, phenethylamine regulates monoamine neurotransmission by binding to trace ami ...
itself,
tyramine
Tyramine ( ) (also spelled tyramin), also known under several other names, is a naturally occurring trace amine derived from the amino acid tyrosine. Tyramine acts as a catecholamine releasing agent. Notably, it is unable to cross the bl ...
,
thyronamine, and
iodothyronamine) – are substituted phenethylamines. Several notable
recreational drug
Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness, either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an Sub ...
s, such as
MDPV (Monkey Dust),
MDMA
3,4-Methylenedioxymethamphetamine (MDMA), commonly known as ecstasy (tablet form), and molly (crystal form), is an empathogen–entactogenic drug with stimulant and minor Psychedelic drug, psychedelic properties. In studies, it has been used ...
(ecstasy),
methamphetamine
Methamphetamine (contracted from ) is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug use, recreational or Performance-enhancing substance, performance-enhancing drug and less commonly as a secon ...
, and
cathinone, are also members of the class. Many well-known prescription drugs are from the phenylethylamine class such as
Adderall
Adderall and Mydayis are trade names for a combination drug containing four salts of amphetamine. The mixture is composed of equal parts racemic amphetamine and dextroamphetamine, which produces a (3:1) ratio between dextroamphetamine and l ...
which uses
Amphetamine
Amphetamine (contracted from Alpha and beta carbon, alpha-methylphenethylamine, methylphenethylamine) is a central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, an ...
, Desoxyn which uses methamphetamine, and Sudafed which uses
pseudoephedrine.
List of substituted phenethylamines
Detection
Detection of substituted phenethylamines, which include compounds such as 2C-B, MDMA, and other designer drugs, involves various analytical methods aimed at identifying these psychoactive substances. These compounds are structurally similar to amphetamines, making their detection challenging due to potential cross-reactivity in standard drug tests. Techniques like
gas chromatography-mass spectrometry (GC-MS),
liquid chromatography-mass spectrometry (LC-MS), and immunoassay screenings are commonly employed for accurate identification. Advanced methods like
high-performance liquid chromatography (HPLC) allow for precise separation and quantification of these substances even at low concentrations. Given the rising use of these drugs in recreational settings, developing sensitive and specific detection techniques remains crucial in forensic toxicology and clinical diagnostics.
Cyclized phenethylamines
There are many
cyclized phenethylamines. Examples include the following:
*
Phenylalkylpyrrolidines like
α-PVP,
pyrovalerone, and
prolintane
*
Tetrahydroisoquinolines like
anhalinine,
pellotine,
lophophorine,
DOM-CR,
nomifensine,
tetrabenazine, and
zelandopam
*
Isoquinoline
Isoquinoline is an individual chemical specimen - a heterocyclic aromatic organic compound - as well as the name of a family of many thousands of natural plant alkaloids, any one of which might be referred to as "an isoquinoline". It is a struc ...
s like
perafensine,
quinisocaine, and
tilisolol
*
Dihydroindoles and
aminochromes like
adrenochrome and
adrenolutin
*
2-Aminoindanes like
2-aminoindane,
MDAI,
MMAI, and
DOM-AI
*
2-Aminotetralins like
2-aminotetralin,
MDAT, and
DOM-AT
*
1-Aminomethylindanes like
2CB-Ind,
AMMI, and
jimscaline
*
Benzazepines like
fenoldopam
*
Benzocyclobutenes like
2CBCB-NBOMe,
S33005,
TCB-2, and
tomscaline
*
Tetrahydrobenzopyranylamines like
CT-5126
*
Benzoxepins like
BBOX,
IBOX
IBox (Internet in a Box) was one of the first commercially available Internet connection software packages available for sale to the public. O'Reilly & Associates (now O'Reilly Media) created and produced the package, in collaboration with Spry, I ...
, and
TFMBOX
*
2-Benzylpiperidines and
phenidates like
2-benzylpiperidine and
methylphenidate
Methylphenidate, sold under the brand names Ritalin ( ) and Concerta ( ) among others, is a central nervous system (CNS) stimulant used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It may be taken Oral adm ...
*
Phenylcyclopropylamines like
tranylcypromine
Tranylcypromine, sold under the brand name Parnate among others, is a monoamine oxidase inhibitor (MAOI). More specifically, tranylcypromine acts as nonselective and irreversible inhibitor of the enzyme monoamine oxidase (MAO). It is used a ...
and
DMCPA
*
3-Phenylpiperidines like
OSU-6162 and
LPH-5
*
Phenylmorpholines like
2-phenylmorpholine,
phenmetrazine,
manifaxine,
radafaxine,
flumexadol,
oxaflozane, and
PF-219,061
*
Phenyloxazolamines or
aminorex analogues like
aminorex and
pemoline
Pemoline, formerly sold under the brand name Cylert among others, is a stimulant medication which was used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy,- it has since been discontinued in most countries due ...
*
Tricyclic compounds like
benzoctamine and
dizocilpine
*
Ergolines and
lysergamides like
LSD
*
Partial ergolines and lysergamides like
NDTDI,
RU-27849,
DEIMDHPCA, and
DEMPDHPCA
* Others like
6-AB,
2-ADN,
2-naphthylamine,
GYKI-52895,
ivabradine,
milnacipran,
Org 6582,
rimiterol, and
ZC-B
Other cyclized phenethylamines have also been described.
Other related families include
phenylpiperazines and
benzylpiperazines.
See also
*
Substituted amphetamine
Substituted amphetamines, or simply amphetamines, are a chemical class, class of compounds based upon the amphetamine structure; it includes all derivative (chemistry), derivative compounds which are formed by replacing, or substitution reacti ...
*
Substituted methylenedioxyphenethylamine
*
Substituted cathinone
Substituted cathinones, or simply cathinones, which include some stimulants and Empathogen-entactogen, entactogens, are chemical derivative, derivatives of cathinone. They feature a substituted phenethylamine, phenethylamine core with an alkyl ...
*
Substituted phenylmorpholine
*
Substituted methoxyphenethylamine
*
2Cs,
DOx,
4Cs,
scalines,
3Cs,
25-NB,
FLY
*
Substituted tryptamine
Substituted tryptamines, or simply tryptamines, also known as serotonin analogues (i.e., 5-hydroxytryptamine analogues), are organic compounds which may be thought of as being derived from tryptamine itself. The molecular structures of all trypt ...
* ''
PiHKAL
''PiHKAL: A Chemical Love Story'' is a book by Alexander Shulgin and Ann Shulgin published in 1991. The subject of the work is Psychoactive drug, psychoactive phenethylamine Derivative (chemistry), chemical derivatives, notably those that act ...
''
* ''
The Shulgin Index''
Notes
References
{{Authority control
Chemical classes of psychoactive drugs