Ch 13 Carboxylic Acids, Esters,
Amines and Amides
SWBAT:
Name/Draw compounds with functional groups
Describe/Explain properties of functional groups
Complete/Show reactions of functional groups
Chapter 13.4
Amines
Amines
• They are derivatives of ammonia NH3
• H-groups are replaced by alkyl or aromatic
groups
Subclasses of Amines
Naming Amines
•
•
•
•
Similar to ether…
List the alkyl groups in alpha order
No gaps
Ends in -amine
methylamine
dimethylamine
Practice
ethylmethylpropylamine
ethyldimethylamine
triphenylamine
Aromatic Amines
• Aromatic amines use the name aniline
• Amino bearing Carbon is C#1
aniline
2,6-diethyl-4-methylaniline
Naming Anilines
•Alkyl groups attached to the nitrogen of the
aniline are named with the prefix Nfollowed by the alkyl name
N-ethylaniline
N, N-dimethylaniline
Properties of Amines
Boiling Point
• Amines can have polar N-H bond, so they can
form H-bonds
• But…N is not as electronegative as the O in
alcohols…so the H-bonds are weaker!
• BP is below Alcohol
Bp differences among different types of amines!
• 1o amines highest BP (2 H-bonds)
• 2o amine lower (1 H-bond)
• 3o amine lowest (only dipole)
Properties of Amines
Solubility
• Amine group is polar: soluble in water, will
form H-bonds
• Small amines (1-5 C atoms) are soluble
• Large amines (<6 C atoms) are not
Famous Amines
• Acetyl choline – neurotransmitter
• Nicotine
Famous Amines
• Prozac – Fluoxetine
• Caffeine
Reaction of Amines
A. 1o and 2o Amines react as Bases – they
accept H+ ions like ammonia below:
The unpaired valence e- of N attract H+
H+
H-N-H + H2O → H-N-H + OHH
H
NH3 + H2O → NH4+ + OHammonia
ammonium ion
Reacting as a Base
• Primary
• Secondary
Dimethylamine
dimethyammonium ion
• Tertiary amines do not react!
Neutralization Reaction
Base + Acid → Salt
NH3 + HCl → NH4+ClAmmonia
Ammonium
chloride (salt)
a) Primary amine
CH3-NH2 + HCl → CH3-NH3+ClMethylamine methylammonium
chloride
b) Similar for secondary amine
Homework
Chapter 13
Page 448 13.34 – 13.44 (even)