AMINES
L.O.:
 What are amines?
 How are they named?
How do they react?
They can be thought of as derivatives of
ammonia in which one or more of the
hydrogen atoms have been replaced by an
alkyl or aryl group.
H
R
N:
H
primary (1°) amines
R
R
N:
R
tertiary (3°) amines
H
R
N:
R
secondary (2°) amines
NOMENCLATURE
Using the suffix amine
C2H5NH2 ethylamine
(CH3)2NH dimethylamine
(CH3)3N trimethylamine
C6H5NH2 phenylamine (aniline)
Different substituents are written in alphabetical
order
H3C
C3H7
N H
methylpropylamine
BOILING POINT
Amines have higher boiling points than
corresponding alkanes because of their
intermolecular hydrogen bonding
Q. Why are the boiling points of amines
lower that the comparable alcohols.
N is less electronegative than O. Hydrogen
bonds are weaker.
SOLUBILITY
Primary amines with chain lengths up to C4
are very soluble in water and alcohols.
C6H5NH2 is not very soluble.
REACTIVITY OF AMINES
The LONE PAIR on the nitrogen atom in 1°, 2° and
3° amines makes them ...
BRØNSTED-LOWRY BASES - they can be proton
acceptors
RNH2
+
H+
——>
RNH3+
NUCLEOPHILES - provide a lone pair to attack an
electron deficient centre