Methanesulfonyl chloride
Encyclopedia
Methanesulfonyl chloride is a compound
containing a sulfonyl chloride used to make methanesulfonate
s and to generate sulfene
.
, and a lachrymator. It should be stored in a dry location, preferably in a desiccator
.
It is manufactured either via direct synthesis from methane
and sulfuryl chloride
in a radical reaction (1):
other method of manufacture starts with methanesulfonic acid
, which is accessible out of methane and sulfur trioxide
(2) or by vigorous oxidation of methanethiol
(3):
The methanesulfonic acid prepared is reacted with thionyl chloride
(4) or phosgene
(5) to form mesyl chloride:
s in the presence of a non-nucleophilic base. Methanesulfonates are used as intermediates in substitution reaction
s, elimination reaction
s, reduction
s, and rearrangement reaction
s. When treated with a Lewis acid
, oxime
methanesulfonates will undergo a facile Beckmann rearrangement
.
Methanesulfonates have been occasionally used as a protecting group
for alcohols. It is stable to acidic conditions and is cleaved back to the alcohol using sodium amalgam
.
s to form a methanesulfonamide
. Unlike a methanesulfonate, a methanesulfonamide is a very stable functional group under both acidic and basic conditions. When used as a protecting group, they can be converted back to amines using lithium aluminium hydride
or a dissolving metal reduction.
, methanesulfonyl chloride will add across alkynes to form β-chloro sulfone
s.
, methanesulfonyl chloride will undergo an elimination
to form sulfene
. Sulfene can undergo cycloaddition
s to form various heterocycles. α-Hydroxyketones react with sulfene to form five-membered sultone
s.
s can be done using methanesulfonyl chloride and a base, typically triethylamine
.
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...
containing a sulfonyl chloride used to make methanesulfonate
Sulfonate
A sulfonate is a salt or ester of a sulfonic acid. It contains the functional group R-SO2O-.- Sulfonate salts:Anions with the general formula RSO2O− are called sulfonates. They are the conjugate bases of sulfonic acids with formula RSO2OH. As sulfonic acids tend to be strong acids, the...
s and to generate sulfene
Sulfene
Sulfene is an extremely unstable chemical compound with the formula H2CSO2. It is the simplest member of the sulfenes, the group of compounds which are S,S-dioxides of thioaldehydes and thioketones, and have the general formula R2CSO2....
.
Preparation, manufacture and handling
Methanesulfonyl chloride is highly toxic, moisture sensitive, corrosiveCorrosive
A corrosive substance is one that will destroy or irreversibly damage another surface or substance with which it comes into contact. The main hazards to people include damage to the eyes, the skin, and the tissue under the skin; inhalation or ingestion of a corrosive substance can damage the...
, and a lachrymator. It should be stored in a dry location, preferably in a desiccator
Desiccator
thumb|right|A desiccator and a vacuum desiccator - note the stopcock which allows a vacuum to be applied. The blue [[silica gel]] in the space below the platform is used as the [[desiccant]]....
.
It is manufactured either via direct synthesis from methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
and sulfuryl chloride
Sulfuryl chloride
Sulfuryl chloride is an inorganic compound with the formula SO2Cl2. At room temperature, it is a colorless liquid with a pungent odor. Sulfuryl chloride is not found in nature, as can be inferred from its rapid hydrolysis....
in a radical reaction (1):
- CH4 (g) + SO2Cl2 (g) → CH3SO2Cl + HCl (g) (1)
other method of manufacture starts with methanesulfonic acid
Methanesulfonic acid
Methanesulfonic acid is a colorless liquid with the chemical formula CH3SO3H. It is the simplest of the alkylsulfonic acids. Salts and esters of methanesulfonic acid are known as mesylates. Methanesulfonic acid is used as an acid catalyst in organic reactions because it is non-volatile, strong acid...
, which is accessible out of methane and sulfur trioxide
Sulfur trioxide
Sulfur trioxide is the chemical compound with the formula SO3. In the gaseous form, this species is a significant pollutant, being the primary agent in acid rain. It is prepared on massive scales as a precursor to sulfuric acid.-Structure and bonding:Gaseous SO3 is a trigonal planar molecule of...
(2) or by vigorous oxidation of methanethiol
Methanethiol
Methanethiol is a colorless gas with a smell like rotten cabbage. It is a natural substance found in the blood and brain of humans and other animal as well as plant tissues. It is disposed of through animal feces. It occurs naturally in certain foods, such as some nuts and cheese...
(3):
- CH4 (g) + SO3 (g) → CH3SO3H (l) (2)
- CH3SH + HNO3 → CH3SO3H + H2O + NOx (3)
The methanesulfonic acid prepared is reacted with thionyl chloride
Thionyl chloride
Thionyl chloride is an inorganic compound with the formula SOCl2. It is a reactive chemical reagent used in chlorination reactions. It is a colorless, distillable liquid at room temperature and pressure that decomposes above 140 °C. Thionyl chloride is sometimes confused with sulfuryl...
(4) or phosgene
Phosgene
Phosgene is the chemical compound with the formula COCl2. This colorless gas gained infamy as a chemical weapon during World War I. It is also a valued industrial reagent and building block in synthesis of pharmaceuticals and other organic compounds. In low concentrations, its odor resembles...
(5) to form mesyl chloride:
- CH3SO3H + SOCl2 → CH3SO2Cl + SO2 + HCl (4)
- CH3SO3H + COCl2 → CH3SO2Cl + CO2 + HCl (5)
Methanesulfonates
The main use of methanesulfonyl chloride is the formation of methanesulfonates from 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 in the presence of a non-nucleophilic base. Methanesulfonates are used as intermediates in substitution reaction
Substitution reaction
In a substitution reaction, a functional group in a particular chemical compound is replaced by another group. In organic chemistry, the electrophilic and nucleophilic substitution reactions are of prime importance...
s, elimination reaction
Elimination reaction
An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one or two-step mechanism...
s, reduction
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
s, and rearrangement reaction
Rearrangement reaction
A rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. Often a substituent moves from one atom to another atom in the same molecule...
s. When treated with a Lewis acid
Lewis acid
]The term Lewis acid refers to a definition of acid published by Gilbert N. Lewis in 1923, specifically: An acid substance is one which can employ a lone pair from another molecule in completing the stable group of one of its own atoms. Thus, H+ is a Lewis acid, since it can accept a lone pair,...
, 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...
methanesulfonates will undergo a facile Beckmann rearrangement
Beckmann rearrangement
The Beckmann rearrangement, named after the German chemist Ernst Otto Beckmann , is an acid-catalyzed rearrangement of an oxime to an amide...
.
Methanesulfonates have been occasionally used as a protecting group
Protecting group
A protecting group or protective group is introduced into a molecule by chemical modification of a functional group in order to obtain chemoselectivity in a subsequent chemical reaction...
for alcohols. It is stable to acidic conditions and is cleaved back to the alcohol using sodium amalgam
Sodium amalgam
Sodium amalgam, commonly denoted Na, is an alloy of mercury and sodium. The term amalgam is used for alloys, intermetallic compounds, and solutions involving mercury as a major component. Sodium amalgam is often used in reactions as strong reducing agents with better handling properties compared...
.
Methanesulfonamides
Methanesulfonyl chloride will react with amineAmine
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,...
s to form a methanesulfonamide
Sulfonamide (chemistry)
In chemistry, the sulfonamide functional group is -S2-NH2, a sulfonyl group connected to an amine group.A sulfonamide is a compound that contains this group. The general formula is RSO2NH2, where R is some organic group. For example, "methanesulfonamide" is CH3SO2NH2...
. Unlike a methanesulfonate, a methanesulfonamide is a very stable functional group under both acidic and basic conditions. When used as a protecting group, they can be converted back to amines using lithium aluminium hydride
Lithium aluminium hydride
Lithium aluminium hydride, commonly abbreviated to LAH or known as LithAl, is an inorganic compound with the chemical formula LiAlH4. It was discovered by Finholt, Bond and Schlesinger in 1947. This compound is used as a reducing agent in organic synthesis, especially for the reduction of esters,...
or a dissolving metal reduction.
Addition to alkynes
In the presence of copper(II) chlorideCopper(II) chloride
Copper chloride is the chemical compound with the formula CuCl2. This is a light brown solid, which slowly absorbs moisture to form a blue-green dihydrate. The copper chlorides are some of the most common copper compounds, after copper sulfate....
, methanesulfonyl chloride will add across alkynes to form β-chloro sulfone
Sulfone
A sulfone is a chemical compound containing a sulfonyl functional group attached to two carbon atoms. The central hexavalent sulfur atom is double bonded to each of two oxygen atoms and has a single bond to each of two carbon atoms, usually in two separate hydrocarbon substituents.-IUPAC name and...
s.
Formation of heterocycles
Upon treatment with a base, such as triethylamineTriethylamine
Triethylamine is the chemical compound with the formula N3, commonly abbreviated Et3N. It is also abbreviated TEA, yet this abbreviation must be used carefully to avoid confusion with triethanolamine, for which TEA is also a common abbreviation....
, methanesulfonyl chloride will undergo an elimination
Elimination reaction
An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one or two-step mechanism...
to form sulfene
Sulfene
Sulfene is an extremely unstable chemical compound with the formula H2CSO2. It is the simplest member of the sulfenes, the group of compounds which are S,S-dioxides of thioaldehydes and thioketones, and have the general formula R2CSO2....
. Sulfene can undergo cycloaddition
Cycloaddition
A cycloaddition is a pericyclic chemical reaction, in which "two or more unsaturated molecules combine with the formation of a cyclic adduct in which there is a net reduction of the bond multiplicity." The resulting reaction is a cyclization reaction.Cycloadditions are usually described by the...
s to form various heterocycles. α-Hydroxyketones react with sulfene to form five-membered sultone
Sultone
In organic chemistry, sultones are cyclic sulfonate esters of hydroxy sulfonic acids that exist mainly as four-, seven-, and sometimes five-membered rings. They are often short-lived intermediates, used as strong alkylating agents to introduce a negatively charged sulfonate group.In the presence of...
s.
Miscellaneous
Forming acyliminium ions from α-hydroxyamideAmide
In chemistry, an amide is an organic compound that contains the functional group consisting of a carbonyl group linked to a nitrogen atom . The term refers both to a class of compounds and a functional group within those compounds. The term amide also refers to deprotonated form of ammonia or an...
s can be done using methanesulfonyl chloride and a base, typically triethylamine
Triethylamine
Triethylamine is the chemical compound with the formula N3, commonly abbreviated Et3N. It is also abbreviated TEA, yet this abbreviation must be used carefully to avoid confusion with triethanolamine, for which TEA is also a common abbreviation....
.