Benzonitrile

Benzonitrile is the chemical compound with the formula C₆H₅(CN), abbreviated PhCN. This aromatic organic compound is a colorless liquid with a sweet bitter almond odour. It is mainly used as a precursor to the resin benzoguanamine.

Production

It is prepared by ammoxidation of toluene, that is its reaction with ammonia and oxygen (or air) at 400 to 450 °C (752 to 842 °F).

C₆H₅CH₃ + 3/2 O₂ + NH₃ → C₆H₅(CN) + 3 H₂O

In the laboratory it can be prepared by the dehydration of benzamide or benzaldehyde oxime or by the Rosenmund–von Braun reaction using cuprous cyanide or NaCN/DMSO and bromobenzene.

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 diphenylmethanimine via reaction with phenylmagnesium bromide followed by methanolysis.

Benzonitrile forms coordination complexes with transition metals that are both soluble in organic solvents and conveniently labile. One example is PdCl₂(PhCN)₂. 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 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

Maki, Takao; Takeda, Kazuo (June 2000). "Benzoic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a03_555. ISBN 3527306730.
Loupy, André; Régnier, Serge (August 1999). "Solvent-free microwave-assisted Beckmann rearrangement of benzaldehyde and 2-hydroxyacetophenone oximes". Tetrahedron Letters. 40 (34): 6221–6224. doi:10.1016/S0040-4039(99)01159-4. ISSN 0040-4039.
Cooper, F. C.; Partridge, M. W. (1963). "N-Phenylbenzamidine". Organic Syntheses; Collected Volumes, vol. 4, p. 769.
Pickard, P. L.; Tolbert, T. L. (1973). "Diphenyl Ketimine". Organic Syntheses; Collected Volumes, vol. 5, p. 520.
Anderson, Gordon K.; Lin, Minren (1990). "Bis(Benzonitrile)Dichloro Complexes of Palladium and Platinum". Reagents for Transition Metal Complex and Organometallic Syntheses. Inorganic Syntheses. Vol. 28. John Wiley & Sons. pp. 60–63. doi:10.1002/9780470132593.ch13. ISBN 978-0-470-13259-3.
Fehling, Hermann (1844). "Ueber die Zersetzung des benzoësauren Ammoniaks durch die Wärme". Annalen der Chemie und Pharmacie. 49 (1): 91–97. doi:10.1002/jlac.18440490106.
McGuire, Brett A.; et al. (January 2018). "Detection of the aromatic molecule benzonitrile (c\sC6H5CN) in the interstellar medium". Science. 359 (6372): 202–205. arXiv:1801.04228. Bibcode:2018Sci...359..202M. doi:10.1126/science.aao4890. PMID 29326270. S2CID 206663501.

External links

International Chemical Safety Card 1103

Molecules detected in outer space

Molecules

Diatomic	Aluminium monochloride Aluminium monofluoride Aluminium(II) oxide Argonium Carbon cation Carbon monophosphide Carbon monosulfide Carbon monoxide Cyano radical Diatomic carbon Fluoromethylidynium Helium hydride ion Hydrogen chloride Hydrogen fluoride Hydrogen (molecular) Hydroxyl radical Iron(II) oxide Magnesium monohydride Methylidyne radical Nitric oxide Nitrogen (molecular) Imidogen Sulfur mononitride Oxygen (molecular) Phosphorus monoxide Phosphorus mononitride Potassium chloride Silicon carbide Silicon monoxide Silicon monosulfide Sodium chloride Sodium iodide Sulfanyl Sulfur monoxide Titanium(II) oxide
Triatomic	Aluminium(I) hydroxide Aluminium isocyanide Amino radical Carbon dioxide Carbonyl sulfide CCP radical Chloronium Diazenylium Dicarbon monoxide Disilicon carbide Ethynyl radical Formyl radical Hydrogen cyanide (HCN) Hydrogen isocyanide (HNC) Hydrogen sulfide Hydroperoxyl Iron cyanide Isoformyl Magnesium cyanide Magnesium isocyanide Methylene N₂H Nitrous oxide Nitroxyl Ozone Methylidynephosphane Potassium cyanide Trihydrogen cation Sodium cyanide Sodium hydroxide Silicon carbonitride c-Silicon dicarbide SiNC Sulfur dioxide Thioformyl Thioxoethenylidene Titanium dioxide Tricarbon Water
Four atoms	Acetylene Ammonia Isocyanic acid Cyanoethynyl Formaldehyde Fulminic acid HCCN Hydrogen peroxide Hydromagnesium isocyanide Isocyanic acid Isothiocyanic acid Ketenyl Methylene amidogen Methyl cation Methyl radical Propynylidyne Protonated carbon dioxide Protonated hydrogen cyanide Silicon tricarbide Thioformaldehyde Tricarbon monoxide Tricarbon monosulfide Thiocyanic acid
Five atoms	Ammonium ion Butadiynyl Carbodiimide Cyanamide Cyanoacetylene Cyanoformaldehyde Cyanomethyl Cyclopropenylidene Formic acid Isocyanoacetylene Ketene Methane Methoxy radical Methylenimine Propadienylidene Protonated formaldehyde Silane Silicon-carbide cluster
Six atoms	Acetonitrile Cyanobutadiynyl radical E-Cyanomethanimine Cyclopropenone Diacetylene Ethylene Formamide HC₄N Ketenimine Methanethiol Methanol Methyl isocyanide Pentynylidyne Propynal Protonated cyanoacetylene
Seven atoms	Acetaldehyde Acrylonitrile Vinyl cyanide Cyanodiacetylene Ethylene oxide Glycolonitrile Hexatriynyl radical Propyne Methylamine Methyl isocyanate Vinyl alcohol
Eight atoms	Acetic acid Aminoacetonitrile Cyanoallene Ethanimine Glycolaldehyde Hexapentaenylidene Methylcyanoacetylene Methyl formate Acrolein
Nine atoms	Acetamide Cyanohexatriyne Dimethyl ether Ethanol Methyldiacetylene Octatetraynyl radical Propene Ethanethiol Propionitrile N-Methylformamide
Ten atoms or more	Acetone Benzene Benzonitrile Buckminsterfullerene (C₆₀, C₆₀, fullerene, buckyball) C₇₀ fullerene Cyanodecapentayne Ethylene glycol Ethyl formate Methyl acetate Methyl-cyano-diacetylene Methyltriacetylene Propionaldehyde Butyronitrile Pyrimidine Heptatrienyl radical

Deuterated
molecules

Unconfirmed

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