Synthetic Routes (Cambridge (CIE) AS Chemistry)

The synthesis of compound X takes place in 2 steps:

Which reagents could be used for this synthesis?

Answer:

• The first step involves a nucleophilic addition of CN^- using NaCN as catalyst and heat to form a hydroxynitrile

• In the second step, the nitrile is refluxed with dilute aqueous sulfuric acid causing hydrolysis of the nitrile forming a carboxylic acid and ammonium salt

The synthesis of hexanoic acid takes place in 2 steps

Which reagents could be used for this synthesis?

Answer:

• Halogenoalkanes can undergo nucleophilic substitution with ethanolic KCN in which the CN^- ion acts as a nucleophile and replaces the chlorine atom in 1-chloropentane to form a nitrile.

• The treatment of nitriles with concentrated hydrochloric acid will produce a carboxylic acid and an ammonium salt.

• In this case, hexanoic acid and ammonium chloride will be formed.