Benzonitrile is the
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 ...
with the formula , abbreviated
PhCN. This
aromatic
In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to satur ...
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. T ...
is a colorless liquid with a sweet bitter
almond odour. It is mainly used as a precursor to the resin
benzoguanamine
Benzoguanamine is an organic compound with the chemical formula (CNH2)2(CC6H5)N3. It is related to melamine but with one amino group replaced by phenyl. Benzoguanamine is used in the manufacturing of melamine resins. Unlike melamine ((CNH2)3N3 ...
.
Production
It is prepared by
ammoxidation
In organic chemistry, ammoxidation is a process for the production of nitriles () using ammonia () and oxygen (). It is sometimes called the SOHIO process, acknowledging that ammoxidation was developed at Standard Oil of Ohio. The usual substrate ...
of
toluene
Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon. It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) a ...
, that is its reaction with
ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...
and oxygen (or air) at .
: + 3/2 + → +
In the laboratory it can be prepared by the dehydration of
benzamide
Benzamide is a organic compound with the chemical formula of C6H5C(O)NH2. It is the simplest amide derivative of benzoic acid
Benzoic acid is a white (or colorless) solid organic compound with the formula , whose structure consists of a benz ...
or by the
Rosenmund–von Braun reaction using
cuprous cyanide
Copper(I) cyanide is an inorganic compound with the formula CuCN. This off-white solid occurs in two polymorphs; impure samples can be green due to the presence of Cu(II) impurities. The compound is useful as a catalyst, in electroplating copper ...
or
NaCN/
DMSO
Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula ( CH3)2. This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds ...
and
bromobenzene
Bromobenzene is an aryl halide, C6H5Br. It is a colourless liquid although older samples can appear yellow. It is a reagent in organic synthesis.
Synthesis and reactions
Bromobenzene is prepared by the action of bromine on benzene in the presenc ...
.
:
Applications
Laboratory uses
Benzonitrile is a useful solvent and a versatile precursor to many derivatives. It reacts with amines to afford N-substituted benzamides after hydrolysis. It is a precursor to diphenylketimine (b.p. 151 °C, 8 mm Hg) via reaction with
phenylmagnesium bromide followed by
methanolysis
In organic chemistry, transesterification is the process of exchanging the organic group R″ of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. The reaction can ...
.
Benzonitrile forms
coordination complex
A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as '' ligands'' or complexing agents. ...
es with transition metals that are both soluble in organic solvents and conveniently labile. One example is
. The benzonitrile ligands are readily displaced by stronger ligands, making benzonitrile complexes useful synthetic intermediates.
History
Benzonitrile was reported by
Hermann Fehling in 1844. He found the compound as a product from the thermal dehydration of
ammonium benzoate. He deduced its structure from the already known analogue reaction of
ammonium formate
Ammonium formate, NH4HCO2, is the ammonium salt of formic acid. It is a colorless, hygroscopic, crystalline solid.
Reductive amination
Acetone can be transformed into isopropylamine as follows:
:CH3C(O)CH3 + 2 HCO2− +NH4 → (CH3)2CHNHCHO + 2 ...
yielding
hydrogen cyanide (
formonitrile). He also coined the name benzonitrile which gave the name to all the group of
nitriles.
In 2018, benzonitrile was reported to be detected in the
interstellar medium.
References
External links
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{{Authority control
Aromatic solvents
Phenyl compounds
Benzonitriles