Benzonitrile
Benzonitrile is the chemical compound with the formula C6H5CN, abbreviated PhCN. This aromatic organic compound is a colorless liquid with a sweet 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 ammonia and oxygen (or air) at 400 to 450 °C.
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.
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 Ph2C=NH (b.p. 151 °C, 8 mm Hg) 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.
Podcasts:
