• Amines?can be thought of as derivates of ammonia, in which one or more of the hydrogens is replaced by an alkyl or aryl group
• The number of substituted hydrogens is the basis of classifying amines

Classification of amines

• Notice the classification is not the same as in alcohols and haloalkanes, where the designation primary, secondary and tertiary is based on the substituents on the?carbon?atom rather than the?nitrogen?atom
• If the R group is an alkyl group (methyl, ethyl, etc) then then it is an?aliphatic amine;?if it is an aryl group (benzene ring or phenyl) then it is an?aromatic amine
• Aliphatic and aromatic amines share similar chemical reactions and the aryl group can strongly influence the chemistry and reactivity of the amine group

Naming Amines

• Amines can be named using common names or IUPAC systematic names
• The common way to name amines is to use the alkyl (or aryl) prefix followed by?-amine
• The IUPAC systematic name uses the numbered prefix?amino-?followed by the alkane (or aromatic) stem

Nomenclature of Aliphatic and Aromatic Amines Table

Amides

• Amides?are formed from the?condensation reaction?of?carboxylic acids?or?acyl chlorides?with?ammonia?or?amines
• Amides are common in nature such as in proteins where the amine and carboxylic acid groups of amino acids bond together
• Amides have a general structure of RCONR2

The general structure of an amide

• Amides can be classified as primary, secondary or tertiary amides
• Like amines, this is done as a comparison to ammonia, depending on the number of substitutions on the amide nitrogen
  • Primary amide - one carbon bonded to the amide nitrogen
    • R' and R'' are both hydrogen atoms so one "ammonia" hydrogen has been substituted with the carbonyl group from the RCO portion of the molecule
  • Secondary amide - two carbons bonded to the amide nitrogen (one MUST be the carbonyl carbon)
  • Tertiary amide - three carbons bonded to the amide nitrogen (one MUST be the carbonyl carbon)

Naming primary amides

• For primary amides, we simply add -amide to the stem name
  • e.g. CH3CONH2
    • Contains two carbons with a C-C (ethan-) and an amide group (-amide)
    • This gives us ethanamide

Naming secondary amides

• For secondary amides, the alkyl chain attached to the nitrogen is added at the start of the chemical name
• This alkyl chain is prefixed with N-
• The chain containing the carbonyl group is named the same as a primary amide
  • e.g.?CH3CONH(C3H7)
    • Contains a propyl group on the nitrogen (N-propyl)
    • Contains two carbons with a C-C (ethan-) and an amide group (-amide)
    • This gives us N-propylethanamide

Naming tertiary amides

• For tertiary amides, there are two alkyl chains attached to the nitrogen
• The naming of these chains is the same as secondary amides
• As with standard nomenclature, these chains are listed in alphabetical order and the prefix 'di-' is used if necessary
  • e.g. CH3CONCH3(C3H7)
    • Contains a methyl group on the nitrogen (N-methyl)
    • Contains a propyl group on the nitrogen (N-propyl)
    • Contains two carbons with a C-C (ethan-) and an amide group (-amide)
    • This gives us N-methyl-N-propylethanamide

Amino acids

• Amino acids?are organic compounds that contain two functional groups:
  • A basic?amino?(-NH2) group
  • An acidic?carboxylic acid?(-COOH) group
• Due to the presence of both a basic and acidic group in amino acids, they are said to be amphoteric
  • They can act as both acids and bases

Naturally occurring amino acids

• 2-aminocarboxylic acids are a type of amino acids in which the amine (-NH2) group is bonded to the carbon atom next to the -COOH group
• These type of amino acids form the ‘building blocks’ that make up?proteins
• There are 20 naturally occurring amino acids with the general structural formula of?RCH(NH2)COOH

General structural formula of amino acids

General structural formula of amino acids

• The?R?group varies in different amino acids and can be:
  • Acidic
  • Basic
  • Neutral

The R group varies in different amino acids