The amide functional group consists of a carbonyl (C=O) group adjacent to a nitrogen atom.

• Primary amides - The nitrogen is bonded to one carbonyl group (C=O) and two hydrogen atoms.
• Secondary amides - The nitrogen is bonded to one carbonyl group (C=O), one hydrogen atom and one alkyl or aryl group.
• Tertiary amides - The nitrogen is bonded to one carbonyl group (C=O), and two alkyl or aryl groups.

Amides are prepared by reacting acyl chlorides with ammonia.

For example, ethanamide can be prepared from ethanoyl chloride and ammonia:

CH₃COCl + 2NH₃ ➔ CH₃CONH₂ + NH₄Cl

Nucleophilic addition-elimination

Amines are stronger bases.

Amides are weaker bases than amines because the lone pair on the nitrogen atom is less available for donation due to the electron-withdrawing effect of the adjacent carbonyl group.

Amides undergo hydrolysis when refluxed with aqueous acid to produce a carboxylic acid and an ammonium salt.

For example, the reaction of ethanamide with hydrochloric acid produces ethanoic acid and NH₄Cl:

CH₃CONH₂ + H₂O +  HCl ➔ CH₃COOH + NH₄Cl

Primary amides undergo hydrolysis when refluxed with aqueous sodium hydroxide to produce the sodium carboxylate salt and ammonia.

For example, the reaction of ethanamide with sodium hydroxide produces sodium ethanoate and NH₃:

CH₃CONH₂ + NaOH ➔ CH₃COONa + NH₃

Amides can be reduced to amines by reacting them with lithium aluminum hydride (LiAlH₄) in dry ether. The amide group (-CONH₂-) is converted to an amine group, (-NH₂).

For example, LiAlH₄ reduces ethanamide to ethylamine:

CH₃CONH₂ + 4[H] ➔ CH₃CH₂NH₂ + H₂O

Amides are prepared by reacting acyl chlorides with primary amines.

For example, N-methylethanamide can be prepared from ethanoyl chloride and methylamine:

CH₃COCl + CH₃NH₂ ➔ CH₃CONHCH₃ + HCl