Lecture on Amide Functional Group

Pronunciation of Amide

• Various pronunciations: "am-ide", "am-ids", "ay-mides"
• Pronunciation often depends on regional differences

Naming Amides

• Amide naming is derived from the corresponding carboxylic acid.

• Example 1: Ethanoic Acid to Ethanamide:

  • Start with ethanoic acid (two-carbon carboxylic acid)
  • Drop "oic acid" from ethanoic acid, add "amide"
  • Common name for ethanoic acid is acetic acid
  • Result: "acetomide" or "acetamid"
  • Primary Amide: Nitrogen bonded to one carbon

• Example 2: Propanoic Acid to Propanamide:

  • Start with propanoic acid (three-carbon carboxylic acid)
  • Drop "oic acid", add "amide"
  • Result: "propanamide"
  • Additional methyl group on nitrogen: "N-methyl-propanamide"
  • Secondary Amide: Nitrogen bonded to two carbons

• Example 3: Butanoic Acid to Butanamide:

  • Start with butanoic acid (four-carbon carboxylic acid)
  • Drop "oic acid", add "amide"
  • Result: "butanamide"
  • Two methyl groups: "N, N-dimethyl-butanamide"
  • Tertiary Amide: Nitrogen bonded to three carbons

• Example 4: Benzamide:

  • Derived from benzoic acid
  • Drop "oic acid", add "amide"
  • Methyl group on nitrogen and carbon four: "N, 4-dimethyl-benzamide"

Physical Properties of Amides

• Acetamide:
  • Solid at room temperature
  • High hydrogen bonding potential
  • Melting point: ~82°C
  • Boiling point: ~221°C
• Strong intermolecular forces due to hydrogen bonding

Solubility in Water

• Small amides are soluble in water (polar interactions)
• Solubility decreases with larger R groups (more non-polar)

Resonance in Amides

• Lone pair on nitrogen can participate in resonance
• Resonance affects polarity and solubility
• Will further discuss resonance in future lectures

Note: Amides have important resonance structures influencing reactivity and chemical reactions.