Cyclopentamine
Encyclopedia
Cyclopentamine is a sympathomimetic alkylamine, classified as a vasoconstrictor. Cyclopentamine was indicated
in the past as an over-the-counter
(OTC) medication
for use as a nasal
decongestant
, notably in Europe
and Australia
, but has now been largely discontinued
possibly due to the availability, effectiveness, and safety of a structurally similar drug, propylhexedrine
.
of propylhexedrine
, differing only in terms of the contracted ring size of a cyclopentane, containing one -CH2- unit less than the cyclohexyl group.
In terms of the acyclic
part of the molecule, both cyclopentamine and propylhexedrine are directly synonymous with methamphetamine
, all three molecules containing the 2-methylaminopropyl side-chain. The obvious difference between them is that whereas methamphetamine is an aromatic molecule containing a phenyl group
, cyclopentamine and propylhexedrine are entirely aliphatic and contain no delocalized electrons at all. The effect that this has on potency is that the reduced alicyclic-alkylamines are weaker than unsaturated (meth)amphetamine.
and cyanoacetic acid.
Condensation of cyclopentanone with cyanoacetic acid in a modified Knoevenagel condensation
followed by decarboxylation affords the unsatured nitrile. Reduction of the double bond and subsequent reaction of the product with methylmagnesium halide leads to the methyl ketone. This affords the desired product on reductive amination with methylamine.
of the catecholamine
neurotransmitter
s norepinephrine
(noradrenaline), epinephrine
(adrenaline), and dopamine
. Its effects on norepinephrine and epinephrine mediate its decongestant effects, while its effects on all three neurotransmitters are responsible for its stimulant properties. When ingested oral
ly in sufficient quantities
, cyclopentamine produces similar effects to amphetamine
, methamphetamine, and propylhexedrine.
Indication (medicine)
In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. The opposite of indication is contraindication.-Drugs:...
in the past as an over-the-counter
Over-the-counter drug
Over-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...
(OTC) medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
for use as a nasal
Human nose
The visible part of the human nose is the protruding part of the face that bears the nostrils. The shape of the nose is determined by the ethmoid bone and the nasal septum, which consists mostly of cartilage and which separates the nostrils...
decongestant
Decongestant
A decongestant or nasal decongestant is a type of drug that is used to relieve nasal congestion.-Pharmacology:The vast majority of decongestants act via enhancing norepinephrine and epinephrine or adrenergic activity by stimulating the α-adrenergic receptors...
, notably in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, but has now been largely discontinued
Discontinuation
Discontinuation is the process of quitting a procedure, such as, the course of treatment with a drug or a consumer product line.*Discontinuation of a treatment is to stop taking a drug...
possibly due to the availability, effectiveness, and safety of a structurally similar drug, propylhexedrine
Propylhexedrine
Propylhexedrine is a stimulant drug related to methamphetamine. It is used mainly to provide temporary symptomatic relief of nasal congestion due to colds, allergies and allergic rhinitis...
.
Chemistry
Cyclopentamine is the cyclopentane homologueHomology (chemistry)
In chemistry, homology refers to the appearance of homologues. A homologue is a compound belonging to a series of compounds differing from each other by a repeating unit, such as a methylene group, a peptide residue, etcetera....
of propylhexedrine
Propylhexedrine
Propylhexedrine is a stimulant drug related to methamphetamine. It is used mainly to provide temporary symptomatic relief of nasal congestion due to colds, allergies and allergic rhinitis...
, differing only in terms of the contracted ring size of a cyclopentane, containing one -CH2- unit less than the cyclohexyl group.
In terms of the acyclic
Acyclic
Acyclic can refer to:* In chemistry, a compound which is not cyclic, e.g. alkanes and acyclic aliphatic compounds* In mathematics:** A graph without a cycle, especially*** A directed acyclic graph...
part of the molecule, both cyclopentamine and propylhexedrine are directly synonymous with methamphetamine
Methamphetamine
Methamphetamine is a psychostimulant of the phenethylamine and amphetamine class of psychoactive drugs...
, all three molecules containing the 2-methylaminopropyl side-chain. The obvious difference between them is that whereas methamphetamine is an aromatic molecule containing a phenyl group
Phenyl group
In organic chemistry, the phenyl group or phenyl ring is a cyclic group of atoms with the formula C6H5. Phenyl groups are closely related to benzene. Phenyl groups have six carbon atoms bonded together in a hexagonal planar ring, five of which are bonded to individual hydrogen atoms, with the...
, cyclopentamine and propylhexedrine are entirely aliphatic and contain no delocalized electrons at all. The effect that this has on potency is that the reduced alicyclic-alkylamines are weaker than unsaturated (meth)amphetamine.
Synthesis
Cyclopentamine can be synthesised starting from cyclopentanoneCyclopentanone
Cyclopentanone is a colorless liquid organic compound with a peppermint-like odor. It is a cyclic ketone, structurally similar to cyclopentane, consisting of a five-membered ring containing a ketone functional group.-Safety:...
and cyanoacetic acid.
Condensation of cyclopentanone with cyanoacetic acid in a modified Knoevenagel condensation
Knoevenagel condensation
The Knoevenagel condensation reaction is an organic reaction named after Emil Knoevenagel. It is a modification of the Aldol condensation.A Knoevenagel condensation is a nucleophilic addition of an active hydrogen compound to a carbonyl group followed by a dehydration reaction in which a molecule...
followed by decarboxylation affords the unsatured nitrile. Reduction of the double bond and subsequent reaction of the product with methylmagnesium halide leads to the methyl ketone. This affords the desired product on reductive amination with methylamine.
Pharmacology
Cyclopentamine acts as a releasing agentReleasing agent
A releasing agent , or simply releaser, is a drug that induces the release of a neurotransmitter from the presynaptic neuron into the synapse, leading to an increase in the extracellular concentrations of the neurotransmitter. Many drugs use neurotransmitter release to exert their psychological and...
of the catecholamine
Catecholamine
Catecholamines are molecules that have a catechol nucleus consisting of benzene with two hydroxyl side groups and a side-chain amine. They include dopamine, as well as the "fight-or-flight" hormones adrenaline and noradrenaline released by the adrenal medulla of the adrenal glands in response to...
neurotransmitter
Neurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...
s norepinephrine
Norepinephrine
Norepinephrine is the US name for noradrenaline , a catecholamine with multiple roles including as a hormone and a neurotransmitter...
(noradrenaline), epinephrine
Epinephrine
Epinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...
(adrenaline), and dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
. Its effects on norepinephrine and epinephrine mediate its decongestant effects, while its effects on all three neurotransmitters are responsible for its stimulant properties. When ingested oral
Oral administration
Oral administration is a route of administration where a substance is taken through the mouth.-Terminology:Per os is an adverbial phrase meaning literally from Latin "by mouth" or "by way of the mouth." The expression is used in medicine to describe a treatment that is taken orally. The...
ly in sufficient quantities
Dose (biochemistry)
A dose is a quantity of something that may impact an organism biologically; the greater the quantity, the larger the dose. In nutrition, the term is usually applied to how much of a specific nutrient is in a person's diet or in a particular food, meal, or dietary supplement...
, cyclopentamine produces similar effects to amphetamine
Amphetamine
Amphetamine or amfetamine is a psychostimulant drug of the phenethylamine class which produces increased wakefulness and focus in association with decreased fatigue and appetite.Brand names of medications that contain, or metabolize into, amphetamine include Adderall, Dexedrine, Dextrostat,...
, methamphetamine, and propylhexedrine.
See also
- AmphetamineAmphetamineAmphetamine or amfetamine is a psychostimulant drug of the phenethylamine class which produces increased wakefulness and focus in association with decreased fatigue and appetite.Brand names of medications that contain, or metabolize into, amphetamine include Adderall, Dexedrine, Dextrostat,...
- CypenamineCypenamineCypenamine, or phenylcyclopentamine, is a stimulant drug. It is currently known only in scientific research and has never been developed for market use. The trans- isomer is reported to be more active than the racemate...
(which is trans-2-phenylcyclopentylamine) - MethamphetamineMethamphetamineMethamphetamine is a psychostimulant of the phenethylamine and amphetamine class of psychoactive drugs...
- PropylhexedrinePropylhexedrinePropylhexedrine is a stimulant drug related to methamphetamine. It is used mainly to provide temporary symptomatic relief of nasal congestion due to colds, allergies and allergic rhinitis...
(also known as cyclohexamine) - TranylcypromineTranylcypromineTranylcypromine is a drug of the substituted phenethylamine and amphetamine classes which acts as a monoamine oxidase inhibitor —it is a non-selective and irreversible inhibitor of the enzyme monoamine oxidase...
(which is trans-2-phenylcyclopropylamine)