Isethionic acid is an
organosulfur compound
Organosulfur compounds are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature abounds with organosulfur compounds—sulf ...
containing an
alkyl
In organic chemistry, an alkyl group is an alkane missing one hydrogen.
The term ''alkyl'' is intentionally unspecific to include many possible substitutions.
An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloal ...
sulfonic acid located beta to a
hydroxy group
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydrox ...
. Its discovery is generally attributed to
Heinrich Gustav Magnus, who prepared it by the action of solid
sulfur trioxide on
ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a h ...
in 1833.
It is a white
water-soluble
In chemistry, solubility is the ability of a substance
Substance may refer to:
* Matter, anything that has mass and takes up space
Chemistry
* Chemical substance, a material with a definite chemical composition
* Drug substance
** Substan ...
solid used in the manufacture of certain
surfactant
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, fo ...
s and in the industrial production of
taurine
Taurine (), or 2-aminoethanesulfonic acid, is an organic compound that is widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine, and accounts for up to 0.1% of total human body weight. It ...
. It is most commonly available in the form of its sodium salt (
sodium isethionate).
Synthesis
Its original synthesis, by the reaction of
sulfur trioxide on
ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a h ...
,
has largely been surpassed. It may be produced by the hydrolysis of
carbyl sulfate, which is obtained by the sulfonation of
ethylene
Ethylene ( IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds).
Ethylene ...
.
:
However the most common route is the reaction of
ethylene oxide
Ethylene oxide is an organic compound with the formula . It is a cyclic ether and the simplest epoxide: a three-membered ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless and flammable gas with a faintly sw ...
with aqueous
sodium bisulfite
Sodium bisulfite (or sodium bisulphite, sodium hydrogen sulfite) is a chemical mixture with the approximate chemical formula NaHSO3. Sodium bisulfite in fact is not a real compound, but a mixture of salts that dissolve in water to give solutions ...
, which produces the sodium salt (
sodium isethionate):
:
Reactions
Isethionic acid is used as a starting material in the industrial production of
taurine
Taurine (), or 2-aminoethanesulfonic acid, is an organic compound that is widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine, and accounts for up to 0.1% of total human body weight. It ...
.
Dehydration of isethionic acid gives
vinylsulfonic acid.
Derivatives
Fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...
esters
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are ...
of isethionic acid (such as
sodium lauroyl isethionate
Sodium is a chemical element with the Symbol (chemistry), symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the ...
and
sodium cocoyl isethionate
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isot ...
) are used as
biodegradable
Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradati ...
anionic
surfactant
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, fo ...
s.
These materials are much milder to skin that other sulfate based surfactants (i.e.
sodium lauryl sulfate
Sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS), sometimes written sodium laurilsulfate, is an organic compound with the formula . It is an anionic surfactant used in many cleaning and hygiene products. This compound is the sodium sal ...
)
making them popular for use in make-up, shampoos and ‘Dove type’ soap bars.
Isethionic acid is also used as a
counter ion in certain pharmaceutical
formulation
Formulation is a term used in various senses in various applications, both the material and the abstract or formal. Its fundamental meaning is the putting together of components in appropriate relationships or structures, according to a formula ...
s, including the
antimicrobial
An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals ...
s
hexamidine and
pentamidine.
Biological importance
Studies made on dog heart slices suggested that heart tissue may be capable of converting
taurine
Taurine (), or 2-aminoethanesulfonic acid, is an organic compound that is widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine, and accounts for up to 0.1% of total human body weight. It ...
to isethionic acid, further experiments demonstrated that this tissue may synthetize taurine from
cystine
Cystine is the oxidized derivative of the amino acid cysteine and has the formula (SCH2CH(NH2)CO2H)2. It is a white solid that is poorly soluble in water. As a residue in proteins, cystine serves two functions: a site of redox reactions and a m ...
.
[{{cite journal, author=W.O Read and J.D.Welty, year=1961, title=Synthesis of Taurine and Isethionic Acid by Dog Heart Slices, journal=The Journal of Biological Chemistry, volume=237, issue=5, pages=1521–1522, doi=10.1016/S0021-9258(19)83734-1, pmid=14490797, doi-access=free]
See also
*
1,3-Propane sultone
1,3-Propane sultone is the organosulfur compound with the formula (CH2)3SO3. It is a cyclic sulfonate ester, a class of compounds called sultones. It is a readily melting colorless solid.
Synthesis
It may be prepared by the acid catalyzed reacti ...
References
Sulfonic acids
Primary alcohols