6.2.4 (c) Reducing Nitriles

(c) reaction of Nitriles from 6.2.4(b):

(i) by reduction (e.g. with H₂/Ni) to form Amines

(ii) by acid hydrolysis to form Carboxylic Acids

ll that Hydroxynitriles are formed from the reaction of Carbonyls (Ketones or Aldehydes) with Hydrogen Cyanide.

In reality, using HCN would be dangerous so NaCN or KCN is used to provide a CN^- ion.

The H⁺ ion comes from Sulphuric Acid.

This is one way of making Carbon chains longer but if a Nitrile is not the desired product then ways are needed to change Nitriles into other substances.

Fortunately, we only need to know about two of these reactions

One definition of reduction is the addition of Hydrogen.

And you should already know that C=C bonds can be hydrogenated/reduced using Hydrogen gas in the presence of a Nickel catalyst.

The same is true for the C≡N.

This is the reduction outlined on the syllabus but the same could be achieved with other reducing agents.

Hydrolysis is to break up a molecule by reacting with water.

In this case a Carboxylic Acid is made.

No mechanism is required so we just need to know how to write the equation.

CH₃CH₂C≡N + 2H₂O + H⁺ --> CH₃CH₂COOH + NH₄⁺