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[[Image:Nitrile-group-2D.png|thumb|150px|The structure of the nitrile group]]
A '''nitrile''' is any [[organic compound]] which has a -[[Carbon|C]]'''≡'''[[Nitrogen|N]] [[functional group]].  The -C'''≡'''N functional group is called a '''nitrile group'''.  In the -CN group, the [[carbon]] atom and the [[nitrogen]] atom are [[triple bond]]ed together.  The prefix '''cyano''' is used in chemical nomenclature to indicate the presence of a nitrile group in a molecule.  A [[cyanide]] ion is a negative ion with the formula CN<sup>−</sup>.  The -CN group is sometimes, less properly, referred to as a ''cyanide group'' or ''cyano group'' and compounds with them are sometimes referred to as [[cyanide]]s.

Nitriles sometimes release the highly toxic CN<sup>−</sup> cyanide ion. See the article on [[cyanide]] for a discussion of biological effects and toxicity.

==History==
[[Hydrogen cyanide]] was first synthesized by [[Carl Wilhelm Scheele|K.W. Scheele]] in 1782 and he was killed in an attempt to get the [[anhydrous]] compound <ref>{{cite journal | title = The Preparation of Nitriles | author = David T. Mowry | journal = [[Chem. Rev.]] | year = 1948 | volume = 42 | issue = 2 | pages = 189 - 283 | doi = 10.1021/cr60132a001}}</ref>. [[Joseph Louis Gay-Lussac|J. L. Gay-Lussac]] was the first to prepare the pure acid in 1811 and [[Friedrich Wohler]] and [[Justus von Liebig]] were the first to prepare the first nitriles ''benzoyl cyanide'' and [[benzonitrile]] in 1832. [[Théophile-Jules Pelouze]] synthesized [[propionitrile]] in 1834.

== Synthesis of nitriles ==<!-- This section is linked from [[Organic reaction]] -->
Nitriles can be prepared in [[organic synthesis]] by the following methods:
* [[Nucleophilic aliphatic substitution]] reactions of [[alkyl halide]]s with metal [[cyanide]]s.
* [[Dehydration reaction|dehydration]] of primary [[amide]]s. Many reagents are available, the combination of [[ethyl dichlorophosphate]] and [[DBU (chemistry)|DBU]] just one of them in this conversion of [[benzamide]] to [[benzonitrile]]:<ref>{{cite journal | title = A convenient new procedure for converting primary amides into nitriles | author = Chun-Wei Kuo, Jia-Liang Zhu, Jen-Dar Wu, Cheng-Ming Chu, Ching-Fa Yao and Kak-Shan Shia | journal = [[Chem. Commun.]] | year = 2007 | volume = 2007 | pages = 301 - 303 | doi = 10.1039/b614061k}}</ref>
:[[Image:Amidedehydration.png|400px|Amide dehydration]]
:Two intermediates in this reaction are amide [[tautomer]] '''A''' and its [[Organophosphate|phosphate]] adduct '''B'''.
* [[Dehydration reaction|dehydration]] of secondary [[amide]]s ([[von Braun amide degradation]])
* [[Dehydration reaction|dehydration]] of [[aldoxime]]s with [[triethylamine]]/[[sulfur dioxide]], [[zeolite]]s, or [[sulfuryl chloride]]
* [[One-pot synthesis]] of [[aldehyde]] with [[hydroxylamine]] and [[sodium sulfate]].
:[[Image:Aldehyde to nitril conversion.png|400px|one-pot synthesis from aldehyde]]

:In one study  <ref>{{cite journal | title = One pot synthesis of nitriles from aldehydes and hydroxylamine hydrochloride using sodium sulphate (anhyd) and sodium bicarbonate in dry media under microwave irradiation | author = Sharwan K, Dewan, Ravinder Singh, and Anil Kumar | journal = [[Arkivoc]] | year = 2006 | pages = (ii) 41-44 | url = http://www.arkat-usa.org/ark/journal/2006/I02_General/1646/05-1646D%20as%20published%20mainmanuscript.pdf | format = [[open access]]}}</ref>  an aromatic or aliphatic aldehyde is reacted with hydroxylamine and [[anhydrous]] sodium sulfate in a [[dry media reaction]] for a very small amount of time under [[microwave chemistry|microwave irradiation]] through an intermediate aldoxime.
* reaction of metal cyanides with aldehydes in the [[cyanohydrin reaction]]
* from [[aryl]] [[carboxylic acid]]s ([[Letts nitrile synthesis]])
* aromatic nitriles from [[diazonium compounds]] in the [[Sandmeyer reaction]]
* from [[alkene]]s and [[alkyne]]s in [[hydrocyanation]]
* A commercial source for the cyanide group is '''diethylaluminum cyanide''' Et<sub>2</sub>AlCN which can be prepared from [[triethylaluminium]] and HCN <ref>{{OrgSynth | collvol = 6 | collvolpages = 436 | year = 1988 | title = Diethylaluminum cyanide | author = W. Nagata and M. Yoshioka | prep = cv6p0436}}</ref>. It has been used in [[nucleophilic addition]] to [[ketone]]s.<ref>{{OrgSynth | collvol = 6 | collvolpages = 307 | year = 1988 | title = PREPARATION OF CYANO COMPOUNDS USING ALKYLALUMINUM INTERMEDIATES: 1-CYANO-6-METHOXY-3,4-DIHYDRONAPHTHALENE | author = W. Nagata, M. Yoshioka, and M. Murakami | prep = cv6p0307}}</ref> For an example of its use see: [[Kuwajima Taxol total synthesis]]
* cyanide ions facilitate the coupling of dibromides. Reaction of α,α'-dibromo [[adipic acid]] with [[sodium cyanide]] in [[ethanol]] yields the cyano [[cyclobutane]]:<ref>{{cite journal | title = RING CLOSURES IN THE CYCLOBUTANE SERIES. II. CYCLIZATION OF α,α′-DIBROMO-ADIPIC ESTERS | author = Reynold C. Fuson, Oscar R. Kreimeier, and Gilbert L. Nimmo | journal = [[J. Am. Chem. Soc.]] | year = 1930 | volume = 52 | issue = 10 | pages = 4074 - 4076 | doi = 10.1021/ja01373a046}}</ref>
:[[Image:CyclobutaneByCyanideMediatedDibromideCoupling.png|300px]]
: In the so-called '''Franchimont Reaction''' (A. P. N. Franchimont, 1872) an α-bromocarboxylic acid is dimerized after hydrolysis of the cyanogroup and [[decarboxylation]] <ref>http://www.drugfuture.com/OrganicNameReactions/ONR143.htm</ref>

== Reactions of nitriles ==
Nitrile groups in organic compounds can undergo various reactions when subject to certain reactants or conditions.  A nitrile group can be hydrolyzed, reduced, or ejected from a molecule as a cyanide ion.

* In [[hydrolysis]] the nitrile is reacted with an acid and water at a high temperature, or with a base and water. The acid hydrolysis forms a [[carboxylic acid]], the alkali hydrolysis forms a [[carboxylate]].
* In [[organic reduction]] the nitrile is reduced by reacting it with [[hydrogen]] with a [[nickel]] [[catalyst]]; an [[amine]] is formed in this reaction. Reduction to the imine followed by hydrolysis to the aldehyde takes place in the [[Stephen aldehyde synthesis]] 
* A nitrile is an [[electrophile]] at the carbon atom in a [[nucleophilic addition]] reactions: 
** with an [[organozinc compound]] in the [[Blaise reaction]]
** and with [[alcohol]]s in the [[Pinner reaction]].
** likewise, the reaction of the [[amine]] [[sarcosine]] with [[cyanamide]] yields [[creatine]]  <ref>{{cite journal | author = Smith, Andri L.; Tan, Paula | url = http://jchemed.chem.wisc.edu/Journal/Issues/2006/Nov/abs1654.html  | title = Creatine Synthesis: An Undergraduate Organic Chemistry Laboratory Experiment | journal = [[J. Chem. Educ.]] | year = 2006 | volume = 83 | pages = 1654}}</ref>
* In '''reductive decyanation''' the nitrile group is replaced by a proton <ref>''The reductive decyanation reaction: chemical methods and synthetic applications'' Jean-Marc Mattalia, Caroline Marchi-Delapierre, Hassan Hazimeh, and Michel Chanon [[Arkivoc]] (AL-1755FR) pp 90-118 '''2006''' [http://www.arkat-usa.org/ark/journal/2006/I04_Lattes/1755/AL-1755FR%20as%20published%20mainmanuscript.asp Article]</ref>. An effective decyanation is by a [[dissolving metal reduction]] with [[HMPA]] and [[potassium]] metal in [[tert-butyl alcohol]]. α-Amino-nitriles can be decyanated with [[lithium aluminium hydride]].
* Nitriles self-react in presence of base in the [[Thorpe reaction]] in a [[nucleophilic addition]]
* In [[organometallic chemistry]] nitriles are known to add to [[alkyne]]s in '''carbocyanation''':<ref>{{cite journal | title = A Dramatic Effect of Lewis-Acid Catalysts on Nickel-Catalyzed Carbocyanation of Alkynes | author =  Yoshiaki Nakao, Akira Yada, Shiro Ebata, and Tamejiro Hiyama | journal = [[J. Am. Chem. Soc.]] | year = 2007 | volume = 129 | issue = 9 | pages = 2428 - 2429| format = Communication | doi = 10.1021/ja067364x}}</ref>
:[[Image:Carbocyanation.png|400px|Carbocyanation Nakao 2007]]

==See also==
* [[:Category:Nitriles]]
* For the [[polymer]] used to make safety gloves, see [[Nitrile rubber]].
* [[Thorpe reaction]]

== External links ==
* {{GoldBookRef | file = N04151 | title = nitrile}}
* {{GoldBookRef | file = C01486 | title = cyanide}}

== References ==
{{reflist|2}}
{{Functional Groups}}

[[Category:Functional groups]]
[[Category:Nitriles]]

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