SCH 4U
Naming Amine by Common and IUPAC
Amines can be named in two ways.
They can be viewed as having an amino group, an -NH2 group, attached to an alkane. This
approach is used for the IUPAC names or they can be seen as having an alkyl group attached to the
nitrogen in the amine. This approach is used in creating common names.
Which type of name is used is a matter of personal preference combined with the complexity of
the compound. Primary amines can usually be named easily either way. Secondary and tertiary
amines are a different story.
IUPAC Names for Primary Amines
If you consider a primary amine to be an amino group attached to an alkane, you would simply
name it as you would an alkane derivative. This is the IUPAC method for naming these compounds.
This is an amine in which the nitrogen is bonded to
one alkyl group and to two hydrogen atoms.
CH3-NH2
Therefore it is a primary amine. The IUPAC name is
aminomethane because the amino group is
aminomethane (or methylamine)
attached to a methane chain. (The common names
are also given here in brackets)
C C C C
This compound contains a chain of four carbon
atoms with an amino group bonded to the second
one. Thus, it is called 2-aminobutane.
N
H
H
2-aminobutane (or sec-butylamine)
C C C
For similar reasons this compound is named 1aminopropane,
N
H
H
1-aminopropane (or propylamine)
C
and this one is named 2-aminopropane.
C
C
N
H
H
2-aminopropane (or isopropylamine)
Common Names for Primary Amines
You can also name primary amines by naming the alkyl group, followed by the word "amine". This
should be written all as one word, even though you may sometimes see the parts written separately.
With this method the compound shown here would CH3-NH2
be named methylamine. (The IUPAC names are
also shown in brackets.)
methylamine (or aminomethane)
This compound is called sec-butylamine,
because it consists of a sec-butyl group (do you
remember that one?) attached to the nitrogen
atom.
C C C C
N
H
H
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SCH 4U
Naming Amine by Common and IUPAC
H
This one would be called propylamine. A more
C C C C N
complete name would be n-propylamine so as to
H
distinguish it from the next compound.
propylamine (or 1-aminopropane)
This compound is called isopropylamine.
As long as you are working with simple alkyl
groups, this is a very straightforward way of
naming amines.
C
C
C
NH2
isopropylamine (or 2-aminopropane)
Common Names for Secondary Amines
Amines which have two alkyl groups attached to the nitrogen are called secondary amines. Secondary
amines are usually named by listing both of the alkyl groups that are attached to the nitrogen, followed
by the name "amine." This is not the IUPAC name however.
In this example there is an ethyl group and a
propyl group attached to the nitrogen.
Consequently, this amine is called
ethylpropylamine.
C C
C
N
C
C
H
ethylpropylamine
Common Names for Tertiary Amines
Amines which have three alkyl groups attached to the nitrogen atom are called tertiary amines. These
also are named by naming each of the alkyl groups attached to the nitrogen, followed by the word
"amine." Again, this is the common name, not the IUPAC name.
An example of a tertiary amine is shown here. This
amine has two methyl groups and one ethyl group
attached to the nitrogen. Consequently, it would be
called dimethylethylamine.
C
C
N
C
C
dimethylethylamine
IUPAC Names for Secondary and Teriary Amines
It is also possible to name secondary and tertiary amines (like those shown above) using the IUPAC
method. To do that, you need to know one additional aspect of the IUPAC methodology. That is using
the letter N to show the location of an alkyl group that is attached to the nitrogen atom.
First, you find and name the longest continuous carbon chain that has the nitrogen attached to it. With
ethylpropylamine that would be propane for the three-carbon chain.
C C
C
N
C
C
H
The parent is thus aminopropane. As the amino group is attached to the 1 carbon of the propane it is
1-aminopropane
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SCH 4U
Naming Amine by Common and IUPAC
Then there is the ethyl group. You have to add that to the name and show where it is attached. Since it
is attached to the nitrogen atom, you put N- rather than a number in front of ethyl, thus N-ethyl-1aminopropane.
Next example:
In this example, the longest continuous chain is an ethane chain with two carbon atoms.
C
C
C
N
C
Again, the nitrogen atom is attached to the number one carbon, so part of the name is 1aminoethane.
Since there are two methyl groups attached to the nitrogen, we add N,N-dimethyl- to the front of the
name. Note each methyl group gets its own locator, thus there are two Ns in the name.
The IUPAC name for this compound is N,N-dimethyl-1-aminoethane.
Choice of Methods
A review the two methods for naming amines based on their structural formulas.
The IUPAC method requires that you first select the longest carbon chain and name the amino groups
and other groups attached to that carbon chain. Show the location of each group attached to the parent
chain by using numbers. Then locate and name any additional groups attached to the nitrogen atom.
Show their location by the symbol N.
The common method requires that you first locate and name the amine group. Then identify and
name each of the attached alkyl groups, putting those names in front of the amine.
Drawing a Structure from a given Name
Coming up with the structure for an amine, given the name, is, of course, just the reverse of the
procedure for naming amines
First look at what kind of name you have.
If it is an IUPAC name,

write down the carbon chain as indicated,

then attach the amino and other groups to it as indicated,

then attach any additional groups to the nitrogen if indicated.
If it is a common name,

write down the nitrogen,

then attach the alkyl groups as indicated.
Then, in both cases, fill in the hydrogen atoms, remembering that each carbon atom has four bonds and
each nitrogen atom has three.
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