• Primary amines?are organic compounds that have an -NH₂?functional group attached to an alkyl or aryl group
• Secondary amines?have two alkyl or aryl groups attached to an -NH group

Primary and secondary amines

• Primary and secondary amines can be prepared from different reactions including:
  • The reaction of halogenoalkanes with ammonia
  • The reaction of halogenoalkanes with primary amines
  • The?reduction?of amides
  • The reduction of nitriles

Reaction of halogenoalkanes with ammonia

• This is a?nucleophilic substitution?reaction in which the nitrogen lone pair in ammonia acts as a?nucleophile?and?replaces?the halogen in the halogenoalkane
• When a halogenoalkane is reacted with?excess, hot ethanolic ammonia under pressure?a?primary amine?is formed

Formation of primary amine

Reaction of halogenoalkanes with primary amine

• This is also a?nucleophilic substitution?reaction in which the nitrogen in the primary amine acts as a?nucleophile?and?replaces?the halogen in the halogenoalkane
• When a halogenoalkane is reacted with a?primary amine?in?ethanol?and?heated in a sealed tube, under pressure?a?secondary amine?is formed

Formation of secondary amine

Reduction of amides

• Amines can also be formed from the?reduction?of?amides?by LiAlH₄?in?dry ether
• Whether a primary or secondary amine is formed depends on the nature of the amide

Amides can be reduced by LiAlH₄?to form amines

Reduction of nitriles

• Nitriles contain a -CN functional group which can be?reduced?to an -NH₂?group
• The nitrile vapour and?hydrogen gas?are passed over a?nickel catalyst?or?LiAlH₄in?dry ether?can be used to form a?primary amine

Nitriles can be reduced with LiAlH₄?or H₂?and Ni catalyst