Neopentyl glycol (
IUPAC
The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...
name: 2,2-dimethylpropane-1,3-diol) is an
organic chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
. It is used in the synthesis of
polyester
Polyester is a category of polymers that contain one or two ester linkages in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include some natura ...
s,
paint
Paint is a material or mixture that, when applied to a solid material and allowed to dry, adds a film-like layer. As art, this is used to create an image or images known as a painting. Paint can be made in many colors and types. Most paints are ...
s,
lubricant
A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, ...
s, and
plasticizer
A plasticizer ( UK: plasticiser) is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture.
Plasticizer ...
s. When used in the manufacture of polyesters, it enhances the stability of the product towards heat, light, and water. By
esterification
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...
reaction with
fatty or
carboxylic
In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl group (e. ...
acids, synthetic lubricating esters with reduced potential for
oxidation
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...
or
hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...
, compared to natural esters, can be produced.
Reactions
Neopentyl glycol is synthesized industrially by the
aldol reaction
The aldol reaction (aldol addition) is a Chemical reaction, reaction in organic chemistry that combines two Carbonyl group, carbonyl compounds (e.g. aldehydes or ketones) to form a new β-hydroxy carbonyl compound. Its simplest form might invol ...
of
formaldehyde
Formaldehyde ( , ) (systematic name methanal) is an organic compound with the chemical formula and structure , more precisely . The compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde. It is stored as ...
and
isobutyraldehyde. This creates the intermediate
hydroxypivaldehyde, which can be converted to neopentyl glycol by either a
Cannizzaro reaction
The Cannizzaro reaction, named after its discoverer Stanislao Cannizzaro, is a chemical reaction which involves the base-induced disproportionation of two molecules of a non-enolizable aldehyde to give a primary alcohol and a carboxylic acid.
...
with excess formaldehyde, or by hydrogenation using palladium on carbon.
[
]
Owing to its tendency to form cyclic derivatives (see
Thorpe-Ingold Effect), it is used as a
protecting group
A protecting group or protective group is introduced into a molecule by chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction. It plays an important role in multistep organic synthesis.
In man ...
for ketones, for example in
gestodene synthesis. Similarly it gives
boronic acid esters, which can be useful in the
cross coupling reactions.
A
condensation reaction
In organic chemistry, a condensation reaction is a type of chemical reaction in which two molecules are combined to form a single molecule, usually with the loss of a small molecule such as water. If water is lost, the reaction is also known as a ...
of neopentyl glycol with
2,6-di-tert-butylphenol
2,6-Di-''tert''-butylphenol is an organic compound with the structural formula 2,6-((CH3)3C)2C6H3OH. This colorless solid alkylated phenol and its derivatives are used industrially as UV stabilizers and antioxidants for hydrocarbon-based produc ...
gives
CGP-7930.
Neopentyl glycol is a precursor to
Neopentyl glycol diglycidyl ether. The sequence begins with alkylation with
epichlorohydrin using a
Lewis acid
A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any ...
catalyst
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...
.
Dehydrochlorination of the resulting
halohydrin with
sodium hydroxide
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula . It is a white solid ionic compound consisting of sodium cations and hydroxide anions .
Sodium hydroxide is a highly corrosive base (chemistry), ...
affords the desired ether.
Research
It has been reported that
plastic crystal A plastic crystal is a crystal composed of weakly interacting molecules that possess some orientational or conformational degree of freedom. The name plastic crystal refers to the mechanical softness of such phases: they resemble waxes and are easil ...
s of neopentyl glycol exhibit a colossal barocaloric effect (CBCEs), which is a cooling effect caused by pressure-induced phase transitions. The obtained entropy changes are about 389 joules per kilogram per kelvin near room temperature. This CBCE phenomenon is likely to be very useful in future solid-state
refrigeration
Refrigeration is any of various types of cooling of a space, substance, or system to lower and/or maintain its temperature below the ambient one (while the removed heat is ejected to a place of higher temperature).IIR International Dictionary of ...
technologies.
[
]
See also
*
Pentaerythritol
Pentaerythritol is an organic compound with the formula C(CH2OH)4. The molecular structure can be described as a neopentane with one hydrogen atom in each methyl group replaced by a hydroxyl (–OH) group. It is therefore a polyol, specifically a ...
*
Trimethylolethane
Trimethylolethane (TME) is the organic compound with the formula CH3C(CH2OH)3. This colorless solid is a triol, as it contains three hydroxy functional groups. More specifically, it features three primary alcohol groups in a compact neopentyl str ...
*
Trimethylolpropane
References
{{Reflist
Monomers
Plasticizers
Alkanediols