Naming amines

For compounds having only an amine has a functional group, the name has three parts:  prefix(es) stem ending
meth - 1 carbon
ethan - 2 carbons
propan - 3 carbons
butan - 4 carbons
pentan - 5 carbons
hexan - 6 carbons

 
2-methylpropan-1-amine

CH3NHCH2CH3
ethylmethylamine


trimethylamine
H2NCH2CH2CH2OH
3-aminopropan-1-ol
 
  1. The ending for amines is -amine 
     
  2. The stem used in the name depends on the number of carbons in the longest chain containing the carbon bonded to N. 
    In the amine at the right, the longest chain including the carbon bonded to nitrogen has three carbon atoms.
     
  3. Substituents on the longest chain are included in the name as prefixes.
    Any atom or group of atoms replacing H at a carbon is called a substituent.  Some common substituents are shown below.
    methyl CH3–
    ethyl CH3CH2–
      
  4. The functional group determines the numbering of the chain.
     
    In an amine, the carbon bonded to N has the lowest possible number.
    Carbon 1 can be at either end of the chain.  In the example above carbon 1 is at the right-hand side.
    If the NH2 group had been at a different position, carbon 1 may have been on the left-hand side.
     
  5. Secondary and tertiary amines may be named just by listing the alkyl groups attached to the nitrogen in alphabetical order.
    Note that the prefixes di- and tri- are used when there is more than on group of the same type.
 

For compounds having other functional groups in addition to NH2, the NH2 is named as a substituent (amino).
Dr Sheila Woodgate
© The University of Auckland 2002