Cyanuric chloride is an
organic compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...
with the
formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...
(NCCl)
3. This white solid is the
chlorinated
In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, ...
derivative of
1,3,5-triazine. It is the
trimer of
cyanogen chloride
Cyanogen chloride is a highly toxic chemical compound with the formula CNCl. This linear, triatomic pseudohalogen is an easily condensed colorless gas. More commonly encountered in the laboratory is the related compound cyanogen bromide, a room-te ...
. Cyanuric chloride is the main precursor to the popular but controversial herbicide
atrazine
Atrazine is a chlorinated herbicide of the triazine class. It is used to prevent pre-emergence broadleaf weeds in crops such as maize (corn), soybean and sugarcane and on turf, such as golf courses and residential lawns. Atrazine's primary manufa ...
.
Production
Cyanuric chloride is prepared in two steps from
hydrogen cyanide
Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on an ...
via the intermediacy of
cyanogen chloride
Cyanogen chloride is a highly toxic chemical compound with the formula CNCl. This linear, triatomic pseudohalogen is an easily condensed colorless gas. More commonly encountered in the laboratory is the related compound cyanogen bromide, a room-te ...
, which is trimerized at elevated temperatures over a carbon catalyst:
:HCN + Cl
2 → ClCN + HCl
:
![Cyanurchloride Synthesis V](https://upload.wikimedia.org/wikipedia/commons/6/6d/Cyanurchloride_Synthesis_V.1.svg)
In 2005, approximately 200,000 tons were produced.
[Klaus Huthmacher, Dieter Most "Cyanuric Acid and Cyanuric Chloride" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. .
]
Industrial uses
It is estimated that 70% of cyanuric chloride is used in the preparation of the triazine-class pesticides, especially
atrazine
Atrazine is a chlorinated herbicide of the triazine class. It is used to prevent pre-emergence broadleaf weeds in crops such as maize (corn), soybean and sugarcane and on turf, such as golf courses and residential lawns. Atrazine's primary manufa ...
. Such reactions rely on the easy displacement of the chloride with
nucleophile
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are ...
s such as amines:
:(ClCN)
3 + 2 RNH
2 → (RNHCN)(ClCN)
2 + RNH
3+Cl
−
Other triazine herbicides, such as
simazine
Simazine is an herbicide of the triazine class. The compound is used to control broad-leaved weeds and annual grasses.
Preparation
Simazine may be prepared from cyanuric chloride and a concentrated solution of ethyl amine (at least 50 perce ...
,
anilazine and
cyromazine are made in an analogous way.
[Ashford's Dictionary of Industrial Chemicals, 3rd edition, 2011, pages 2495-8]
Cyanuric chloride is also used as a precursor to dyes and crosslinking agents. The largest class of these dyes are the sulfonated triazine-stilbene optical brighteners (OBA) or fluorescent whitening agents (FWA) commonly found in detergent formulas and white paper.
[ Many ]reactive dyes
In a reactive dye, a chromophore (an atom or group whose presence is responsible for the colour of a compound) contains a substituent that chemical reaction, reacts with the substrate. Reactive dyes have good fastness properties owing to the covale ...
also incorporate a triazine ring. They are also manufactured by way of the chloride displacement reaction shown above.
Organic synthesis
In one specialized application, cyanuric chloride is employed as a reagent
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...
in organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one o ...
for the conversion of alcohols and carboxylic acids into alkyl and acyl chlorides, respectively:
:
It is also used as a dehydrating agent and for the activation of carboxylic acids for reduction to alcohols. Heating with DMF gives "Gold's reagent" Me2NCH=NCH=NMe2+Cl−, which is a versatile source of aminoalkylations and a precursor to heterocycles.
The chloride centers are easily replaced by amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituen ...
s to give melamine
Melamine is an organic compound with the formula C3H6N6. This white solid is a trimer of cyanamide, with a 1,3,5-triazine skeleton. Like cyanamide, it contains 67% nitrogen by mass, and its derivatives have fire retardant properties due t ...
derivatives, for example in the synthesis of dendrimer
Dendrimers are highly ordered, branched polymeric molecules. Synonymous terms for dendrimer include arborols and cascade molecules. Typically, dendrimers are symmetric about the core, and often adopt a spherical three-dimensional morphology. The ...
s:
:
It is also employed the synthesis of an experimental adenosine receptor
The adenosine receptors (or P1 receptors) are a class of purinergic G protein-coupled receptors with adenosine as the endogenous ligand. There are four known types of adenosine receptors in humans: A1, A2A, A2B and A3; each is encoded by a di ...
ligand.:
:
Cyanuric chloride can also be used as an alternative to oxalyl chloride
Oxalyl chloride is an organic chemical compound with the formula (COCl)2. This colorless, sharp-smelling liquid, the diacyl chloride of oxalic acid, is a useful reagent in organic synthesis.
Preparation
Oxalyl chloride was first prepared in 1892 ...
in the Swern oxidation
The Swern oxidation, named after Daniel Swern, is a chemical reaction whereby a primary or secondary alcohol is oxidized to an aldehyde or ketone using oxalyl chloride, dimethyl sulfoxide (DMSO) and an organic base, such as triethylamine. It is one ...
.
See also
* Thiazyl chloride trimer - structural analogue with sulfur atoms in-place of carbon
References
{{Reflist
Inorganic chlorine compounds
Triazines
Dehydrating agents