Amines and Amides

  1. Amines
    • bases, substituted ammonia
    • biologically significant: amino acids, DNA, RNA bases, alkaloids
  2. General formula for primary amine
  3. General formula for secondary amine
  4. General formula for tertiary amine
  5. General formula for quaternary
  6. More information on amines
    • organic derivative of ammonia (NH3) in which 1 or more hydrogen atoms have been replaced by an alkyl, acycloakly, or an aryl group (beneze ring)
    • N has 5 valence e-, 3 covalent bonds, and 1 nonbonding electron pair
    • N is also less electronegative than O
    • N is one of the elements involved in the formation of H+ bonding
  7. Properties of amines
    • N is very electronegative (although less than O)
    • Results in:
    • -N-H bond being very polar
    • -hydrogen bonding being possible
    • -high boiling points
    • -amines being organic bases
  8. Classification of amines
    • determined by the number of carbon atom directly boned to the N atom
    • classified as: primary, secondary, or tertiary
    • Note: t-butyl alcohol is a t-alcohol, while t-butyl amine is a primary amine
  9. Causes of isomers in amines
    • different carbon atom arrangements produce isomers
    • different positioning of the nitrogen atom on a carbon chain
  10. Causes of isomers for secondary and tertiary amines
    • different partititioning of carbon atoms among the carbon chain
    • ex: CH3CH2NHCH2CH3- diethyl amine
    • CH3NHCH2CH2CH3- methylpropyl amine
    • CH3NHCH[2(CH3)]
  11. Amine nomenclature
    • Both common and IUPAC names are used
    • Simple amines are named by listing the alkyl group or groups attched to the N atom in alphabetical order and adding the suffix -amine
    • appears as 1 word
    • prefix di and tri are used when identical groups are bonded to the N atom
  12. Naming diamines
    • in diamines the final -e of the carbon chain is retained
    • ex.1,4- butanediamine
    • NH2CH2CH2CH2CH2NH2
  13. Nomenclature of secondary & tertiary amines
    • treat additional branches as a substituent on the nitrogen
    • base name is based on longest chain that contains the amine
    • name other chain as alkyl substituent of the N
    • use N- at front of a branch name to indicate that substituant is on the nitrogen
  14. Naming aromatic amines
    • aniline is the simplest aromatic amine
    • compounds are named as substituted anilines
    • anitalic "N" is used to indicate that an alkyl group is attached to the nitrogen and not to the ring
  15. Physical properties of amines
    • methylamines and ethylamines are gases at room temp & have ammonia like odor
    • most other amines are liquid & have odor resembling fish
    • have the ability to form H-bonding
  16. Boiling points of amines
    boiling points are intermediate b/w those of alcohols and alkenes of similar molecular masses
  17. solubility of amines
    low molecular mass amines are very soluble in water
  18. Amines+acid--->
    • amines+acid--->salt
    • ex. R-NH2+HCl---> R-NH3+ + Cl-
  19. Basicity of amines
    NH3 + water---> NH4+ + OH-
  20. Basicity of amines generalizations
    • substituted ammonia ions are always charged species rather than neutral molecules
    • N atom in the structure participates in 4 bonds
    • substituted ammonium ions have common names derived from the names of the "parent" amines w/ the words ammonium ion replacing amine
    • -examples in notes
  21. Production from ammonia and an alcohol uses:
    Al2O3 & heat
  22. Preparation of amines:
    ammonia + alkylhalide in the presence of a base
    ex.ammonia+ ethyl bromide+ sodium hydroxide--->aminoethane+sodiumbromide+water
  23. Preparation of amines:
    amine+water---> ammonium ion+hydroxide
  24. Preparation of amines:
    amine salt+base--->
    amine salt+base--->amine+salt+water
  25. Neutralization formula of an amine
    • RNH2+HCl--->RNH3+ Cl-
    • Note: no H2O os produced in this reaction
    • Amine salts are the only product
  26. Neutralization
    • 1.salts exist as white crystalline solids
    • 2.reliatively high melting points
    • 3.salts are always more soluble
    • 4.many drugs are prepared and administered as salts b/c of their solublitiy
  27. General formula for amides
  28. amide nomenclature
    drop -e ending and replace w/ -amide
  29. Amide formation
    amines react w/ acid chlorides or acid anhydrides to form amides
  30. Preparation of amides
    production from a carboxylic acid uses:
    NH3 & heat
Card Set
Amines and Amides
Amines and Amides Chapter 16