1. HCN and CN– in synthesis
Increasing carbon chain length

2. Formation of C–CN Reaction of haloalkanes with CN–
RBr + CN–  RCN + Br–
Reaction of carbonyl compounds with HCN:
Aldehydes: RCHO + HCN  RCH(CN)COH
Ketones: RCOR’ + HCN  RCR’(CN)COH

3. Haloalkane  nitrile Reagents and conditions
CN– ions, e.g. KCN(aq) in ethanol solvent
Mechanism:
Nucleophilic substitution
C–C bond forms
charge
lone pair

4. Carbonyl nitrile Reagents and conditions
CN– ions in dilute acid, e.g. KCN(aq)/H2SO4(aq)
Mechanism:
Nucleophilic addition
charge
lone pair
C–C bond forms

5. Nitriles in synthesis Reduction  amines H2 and Ni catalyst
Acid hydrolysis  carboxylic acids
Aqueous acid, H+/H2O, e.g. HCl(aq)
amine
nitrile
carboxylic acid
nitrile