Amyl nitrite
Encyclopedia
Amyl nitrite is the chemical compound
with the formula
C5H11ONO. A variety of isomers are known, but they all feature an amyl
group attached to the nitrito functional group
. The alkyl group is unreactive and the chemical and biological properties are mainly due to the nitrite group. Like other alkyl nitrites, amyl nitrite is bioactive in mammals, being a vasodilator, which is the basis of its use as a prescription medicine. As an inhalant, it also has a psychoactive
effect, which has led to its recreational use.
Despite a very similar name to amyl nitrite, amyl nitrate
has a different chemical composition and different properties.
s with nitrous acid
:
The reaction is called esterification. Synthesis of alkyl nitrites is, in general, straightforward and can be accomplished in home laboratories. A common procedure includes the dropwise addition of concentrated sulfuric acid to a cooled mixture of an aqueous sodium nitrite solution and an alcohol. The intermediately-formed stoichiometric mixture of nitrous and nitric oxide then converts the alcohol to the alkyl nitrite, which, due to its low density, will form an upper layer that can be easily decanted
from the reaction mixture.
Isoamyl nitrite decomposes in the presence of base to give nitrite salts and the isoamyl alcohol
:
Amyl nitrite, like other alkyl nitrites, reacts with carbanion
s to give oxime
s.
Amyl nitrites are also useful as reagents in a modification of the Sandmeyer reaction
. The reaction of the alkyl nitrite with an aromatic amine
in a halogenated solvent produces a radical
aromatic species, this then abstracts a halogen
atom from the solvent. For the synthesis of aryl iodide
s diiodomethane
is used, whereas bromoform
is the solvent of choice for the synthesis of aryl bromide
s.
, is a potent vasodilator (i.e., it expands blood vessel
s, resulting in lowering of the blood pressure
). Alkyl nitrites function as a source of nitric oxide
, which signals for relaxation of the involuntary muscles. Physical effects include decrease in blood pressure, headache, flushing of the face, increased heart rate, dizziness, and relaxation of involuntary muscles, especially the blood vessel
walls and the anal sphincter. There are no withdrawal
symptoms. Overdose symptoms include nausea
, emesis (vomiting), hypotension
, hypoventilation
, dyspnea
(shortness of breath), and syncope (fainting). The effects set in very quickly, typically within a few seconds and disappear soon after (within minutes).
It induces the formation of methemoglobin, which sequesters cyanide as nontoxic cyanomethemoglobin.
s such as angina and also to treat cyanide poisoning
. It is also used as an inhalant
drug that induces a brief euphoric state, and when combined with other intoxicatant stimulant drugs such as cocaine
or ecstasy (see MDMA), the euphoric state intensifies and is prolonged. Once some stimulative drugs wear off, a common side effect is a period of depression
or anxiety
, colloquially called a "come down"; amyl nitrite is sometimes used to combat these negative after-effects. This effect, combined with its dissociative effects, makes it an attractive but risky recreational drug (see poppers
).
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
C5H11ONO. A variety of isomers are known, but they all feature an amyl
Amyl
The word or root amyl has two meanings, in organic chemistry and biochemistry.-Biochemistry:In biochemistry, "amyl" means "pertaining to starch", "amylum" being another word for starch...
group attached to the nitrito functional group
Functional group
In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...
. The alkyl group is unreactive and the chemical and biological properties are mainly due to the nitrite group. Like other alkyl nitrites, amyl nitrite is bioactive in mammals, being a vasodilator, which is the basis of its use as a prescription medicine. As an inhalant, it also has a psychoactive
Psychoactive drug
A psychoactive drug, psychopharmaceutical, or psychotropic is a chemical substance that crosses the blood–brain barrier and acts primarily upon the central nervous system where it affects brain function, resulting in changes in perception, mood, consciousness, cognition, and behavior...
effect, which has led to its recreational use.
Nomenclature
The term "amyl nitrite" encompasses several isomers. For example, a common form of amyl nitrite with the formula (CH3)2CHCH2CH2ONO may be more specifically referred to as isoamyl nitrite. When the amyl group is a linear or normal (n) alkyl group, the resulting amyl nitrite would have the structural formula CH3(CH2)4ONO.Despite a very similar name to amyl nitrite, amyl nitrate
Amyl nitrate
Amyl nitrate is the chemical compound with the formula CH34ONO2. This molecule consists of the 5-carbon amyl group attached to a nitrate functional group. It is the ester of amyl alcohol and nitric acid.-Applications:...
has a different chemical composition and different properties.
Synthesis and reactions
Alkyl nitrites are prepared by the reaction of alcoholAlcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s with nitrous acid
Nitrous acid
Nitrous acid is a weak and monobasic acid known only in solution and in the form of nitrite salts.Nitrous acid is used to make diazides from amines; this occurs by nucleophilic attack of the amine onto the nitrite, reprotonation by the surrounding solvent, and double-elimination of water...
:
- C5H11OH + HONO → C5H11ONO + H2O
The reaction is called esterification. Synthesis of alkyl nitrites is, in general, straightforward and can be accomplished in home laboratories. A common procedure includes the dropwise addition of concentrated sulfuric acid to a cooled mixture of an aqueous sodium nitrite solution and an alcohol. The intermediately-formed stoichiometric mixture of nitrous and nitric oxide then converts the alcohol to the alkyl nitrite, which, due to its low density, will form an upper layer that can be easily decanted
Decantation
Decantation is a process for the separation of mixtures. This is achieved by carefully pouring a solution from a container in order to leave the precipitate in the bottom of the original container...
from the reaction mixture.
Isoamyl nitrite decomposes in the presence of base to give nitrite salts and the isoamyl alcohol
Amyl alcohol
An amyl alcohol is any of 8 alcohols with the formula C5H11OH. A mixture of amyl alcohols can be obtained from fusel alcohol. Amyl alcohol is used as a solvent and in esterfication for example in the production of amyl acetate...
:
- C5H11ONO + NaOH → C5H11OH + NaNO2Sodium nitriteSodium nitrite is the inorganic compound with the chemical formula NaNO2. It is a white to slight yellowish crystalline powder that is very soluble in water and is hygroscopic...
Amyl nitrite, like other alkyl nitrites, reacts with carbanion
Carbanion
A carbanion is an anion in which carbon has an unshared pair of electrons and bears a negative charge usually with three substituents for a total of eight valence electrons. The carbanion exists in a trigonal pyramidal geometry. Formally a carbanion is the conjugate base of a carbon acid.where B...
s to give oxime
Oxime
An oxime is a chemical compound belonging to the imines, with the general formula R1R2C=NOH, where R1 is an organic side chain and R2 may be hydrogen, forming an aldoxime, or another organic group, forming a ketoxime. O-substituted oximes form a closely related family of compounds...
s.
Amyl nitrites are also useful as reagents in a modification of the Sandmeyer reaction
Sandmeyer reaction
The Sandmeyer reaction is a chemical reaction used to synthesize aryl halides from aryl diazonium salts. It is named after the Swiss chemist Traugott Sandmeyer....
. The reaction of the alkyl nitrite with an aromatic amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
in a halogenated solvent produces a radical
Radical (chemistry)
Radicals are atoms, molecules, or ions with unpaired electrons on an open shell configuration. Free radicals may have positive, negative, or zero charge...
aromatic species, this then abstracts a halogen
Halogen
The halogens or halogen elements are a series of nonmetal elements from Group 17 IUPAC Style of the periodic table, comprising fluorine , chlorine , bromine , iodine , and astatine...
atom from the solvent. For the synthesis of aryl iodide
Organoiodine compound
Organoiodine compounds are organic compounds that contain one or more carbon–iodine bonds. They occur widely in organic chemistry, but are relatively rare in nature...
s diiodomethane
Diiodomethane
Diiodomethane or methylene iodide, commonly abbreviated "MI", is a liquid organoiodine compound. It is insoluble in water, but soluble in ether and alcohol. It has a relatively high refractive index of 1.741, and a surface tension of 0.0508 N·m−1...
is used, whereas bromoform
Bromoform
Bromoform is a pale yellowish liquid with a sweet odor similar to chloroform, a halomethane or haloform. Its refractive index is 1.595 . Bromoform is produced naturally by phytoplankton and seaweeds in the ocean and this is thought to be the predominant source to the environment...
is the solvent of choice for the synthesis of aryl bromide
Organobromine compound
Organobromine compounds are organic compounds that contain carbon bonded to bromine. The most pervasive is the naturally produced bromomethane. One prominent application is the use of polybrominated diphenyl ethers as fire-retardants. A variety of minor organobromine compounds are found in...
s.
Physiological effects
Amyl nitrite, in common with other alkyl nitritesAlkyl nitrites
Alkyl nitrites are a group of chemical compounds based upon the molecular structure R-ONO. Formally they are alkyl esters of nitrous acid. They are distinct from nitro compounds ....
, is a potent vasodilator (i.e., it expands blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
s, resulting in lowering of the blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
). Alkyl nitrites function as a source of nitric oxide
Nitric oxide
Nitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...
, which signals for relaxation of the involuntary muscles. Physical effects include decrease in blood pressure, headache, flushing of the face, increased heart rate, dizziness, and relaxation of involuntary muscles, especially the blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
walls and the anal sphincter. There are no withdrawal
Withdrawal
Withdrawal can refer to any sort of separation, but is most commonly used to describe the group of symptoms that occurs upon the abrupt discontinuation/separation or a decrease in dosage of the intake of medications, recreational drugs, and alcohol...
symptoms. Overdose symptoms include nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, emesis (vomiting), hypotension
Hypotension
In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
, hypoventilation
Hypoventilation
In medicine, hypoventilation occurs when ventilation is inadequate to perform needed gas exchange...
, dyspnea
Dyspnea
Dyspnea , shortness of breath , or air hunger, is the subjective symptom of breathlessness.It is a normal symptom of heavy exertion but becomes pathological if it occurs in unexpected situations...
(shortness of breath), and syncope (fainting). The effects set in very quickly, typically within a few seconds and disappear soon after (within minutes).
It induces the formation of methemoglobin, which sequesters cyanide as nontoxic cyanomethemoglobin.
Applications
Amyl nitrite is employed medically to treat heart diseaseIschaemic heart disease
Ischaemic or ischemic heart disease , or myocardial ischaemia, is a disease characterized by ischaemia of the heart muscle, usually due to coronary artery disease...
s such as angina and also to treat cyanide poisoning
Cyanide poisoning
Cyanide poisoning occurs when a living organism is exposed to a compound that produces cyanide ions when dissolved in water. Common poisonous cyanide compounds include hydrogen cyanide gas and the crystalline solids potassium cyanide and sodium cyanide...
. It is also used as an inhalant
Inhalant
Inhalants are a broad range of drugs whose volatile vapors are taken in via the nose and trachea. They are taken by volatilization, and do not include drugs that are inhaled after burning or heating...
drug that induces a brief euphoric state, and when combined with other intoxicatant stimulant drugs such as cocaine
Cocaine
Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
or ecstasy (see MDMA), the euphoric state intensifies and is prolonged. Once some stimulative drugs wear off, a common side effect is a period of depression
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
or anxiety
Anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
, colloquially called a "come down"; amyl nitrite is sometimes used to combat these negative after-effects. This effect, combined with its dissociative effects, makes it an attractive but risky recreational drug (see poppers
Poppers
Poppers is a slang term for various alkyl nitrites inhaled for recreational purposes, particularly isopropyl nitrite and isobutyl nitrite , and now more rarely, butyl nitrite and amyl nitrite...
).