3. amines and amides

• adrenaline 


  important role in the fight-or-flight response by increasing blood flow to muscles, output of the heart, pupil dilation, and blood sugar.
• Ecstasy (MDMA)


  psychoactive drug used primarily as a recreational drug. Desired effects of MDMA include increased empathy, euphoria, and heightened sensations.
• Serotonin 


  popularly thought to be a contributor to feelings of well-being and happiness
• naming amines


  -amine / amino-
• methylamine

  
• Amines can be classified as primary, secondary, tertiary or quaternary (quaternary ammonium salts).
• primary amines

  
• secondary amines

  
• tertiary amines

  
• diethylamine


  used when 2 identical R groups are attached

  
• triethylamine

  
• trimethylamine

  
• methylphenylamine

  
• basicity of amines 


  main feature of amines is that they have a lone pair of electrons on the nitrogen
• basicity of amines


  the amine is using its lone pair to form a dative bond to the hydrogen ion
• bronsted-lowry base


  proton acceptor
• what does base strength depend on?

  • The availability of the lone pair of electrons on the nitrogen atom.
  • The amine will be a stronger base if the lone pair of electrons are more available to accept a proton.
• Alkyl amines are stronger bases than ammonia


  The methyl group is electron releasing relative to hydrogen therefore pushes electron density towards the N making the lone pair on the N more readily donated to a H+ ion.
• Aromatic amines are weaker bases than ammonia. 


  The lone pair of electrons on the N interact with the delocalised electrons in the ring, and so the lone pair on the N is less readily donated to a H+ ion.
• Would you expect the base strength of phenylmethylamine to be typical of an alkylamine or an aromatic amine?

  An alkylamine, as the nitrogen atom is not directly bonded to the benzene ring.