Benzonitrile

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Benzonitrile
Skeletal formula Ball-and-stick model
Identifiers
CAS number 100-47-0 YesY
PubChem 7505
ChemSpider 7224 YesY
UNII 9V9APP5H5S YesY
KEGG C09814 YesY
ChEBI CHEBI:27991 YesY
ChEMBL CHEMBL15819 YesY
Jmol-3D images Image 1
Properties
Molecular formula C7H5N
Molar mass 103.12 g/mol
Density 1.0 g/ml
Melting point −13 °C (9 °F; 260 K)
Boiling point 188 to 191 °C (370 to 376 °F; 461 to 464 K)
Solubility in water <0.5 g/100 ml (22 °C)
Refractive index (nD) 1.5280
Hazards
EU Index 608-012-00-3
EU classification Harmful (Xn)
R-phrases R21/22
S-phrases (S2), S23
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 75 °C (167 °F; 348 K)
Autoignition temperature 550 °C (1,022 °F; 823 K)
Explosive limits 1.4–7.2%
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Benzonitrile is the chemical compound with the formula C6H5CN, abbreviated PhCN. This aromatic organic compound is colourless, with a sweet almond odour. It is mainly used as a precursor to the resin benzoguanamine.

Production[edit]

It is prepared by ammoxidation of toluene, that is its reaction ammonia and oxygen (or air) at 400 to 450 °C.[1]

C6H5CH3 + 3/2 O2 + NH3 → C6H5CN + 3 H2O

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

Rosenmund-von Braun synthesis

Applications[edit]

Laboratory uses[edit]

Benzonitrile is a useful solvent and a versatile precursor to many derivatives. It reacts with amines to afford N-substituted benzamides after hydrolysis.[2] It is a precursor to Ph2C=NH (b.p. 151 °C, 8 mm Hg) via reaction with phenylmagnesium bromide followed by methanolysis.[3]

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.[4]

History[edit]

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 formonitrile. He also coined the name benzonitrile which gave the name to all the group of nitriles.[5]

References[edit]

  1. ^ Takao Maki, Kazuo Takeda "Benzoic Acid and Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a03_555.
  2. ^ Cooper, F.C.; Partridge, M. W. (1963), "N-Phenylbenzamidine", Org. Synth. ; Coll. Vol. 4: 769 
  3. ^ Pickard, P. L.; Tolbert, T. L. (1973), "Diphenyl Ketimine", Org. Synth. ; Coll. Vol. 5: 520 
  4. ^ Gordon K. Anderson, Minren Lin (1990). "Bis(Benzonitrile)Dichloro Complexes of Palladium and Platinum". Inorganic Syntheses. Inorganic Syntheses 28: 60–63. doi:10.1002/9780470132593.ch13. ISBN 978-0-470-13259-3. 
  5. ^ Hermann Fehling (1844). "Ueber die Zersetzung des benzoësauren Ammoniaks durch die Wärme". Annalen der Chemie und Pharmacie 49 (1): 91–97. doi:10.1002/jlac.18440490106. 

External links[edit]