1. Chapter 14 Carboxylic Acids, Esters, Amines, and Amides
14.4
Amines

2. Amines Amines are derivatives of ammonia, NH3
contain N attached to one or more alkyl or aromatic groups
CH3 CH3
 
CH3—NH CH3—NH CH3—N—CH3

3. Classification of Amines
Amines are classified as primary, secondary, or tertiary:
a primary (1) amine has one carbon group bonded to the nitrogen atom
a secondary (2) amine has two carbon groups bonded to the nitrogen atom
a tertiary (3) amine has three carbon groups bonded to the nitrogen atom
H CH CH3
| | |
CH3—N—H CH3—N—H CH3—N—CH3
1° ° °

4. Skeletal Structures of Amines
The skeletal structures show the shapes of amine molecules with one or more alkyl groups bonded to the nitrogen atom.

5. Naming Amines Simple amines are named as alkylamines
list the names of the alkyl groups bonded to the N atom
in alphabetical order in front of amine
CH3—CH2—NH2 Ethylamine
CH3—NH—CH3 Dimethylamine
CH3 |
CH3—N—CH2—CH3 Ethyldimethylamine

6. Learning Check
Give the common name and classify as primary, secondary, or tertiary. A. CH3—CH2—CH2—NH2 CH3 | B. CH3—CH2—N—CH3

7. Solution
A. CH3—CH2—CH2—NH2 propylamine, 1 CH3 | B. CH3—CH2—N—CH3 ethyldimethylamine, 3

8. Aromatic Amines The amine of benzene is named aniline.
Alkyl groups on the N use the prefix N− with alkyl name.
N-methylaniline aniline chloroaniline

9. Learning Check Give the common name of each compound.
A. CH3—NH—CH2—CH3
CH3 |
B. CH3—CH2—N—CH2—CH C.

10. Solution Give the common name of each compound. A. CH3—NH—CH2—CH3
ethylmethylamine
CH3 |
B. CH3—CH2—N—CH2—CH C.
diethylmethylamine aniline

11. Properties of Amines 1 and 2 amines
can form hydrogen bonds with each other and water molecules
can form hydrogen bonds, while amines with less than six carbons are soluble in water because they form hydrogen bonds with water
3 amines can only form hydrogen
bonds with water molecules

12. Learning Check
Consider the compounds below: 1. Which compound cannot form hydrogen bonds with other amines? 2. Which compound is not soluble in water? A. CH3—CH2—CH2—NH2 B. CH3—CH2—NH—CH3 C. CH3—CH2—CH2—CH3

13. Solution
Consider the compounds below: 1. Which compound cannot form hydrogen bonds with other amines? CH3—CH2—CH2—CH3 C is an alkane, which cannot form hydrogen bonds with each other. 2. Which compound is not soluble in water? CH3—CH2—CH2—CH3 C is an alkane and therefore not soluble in water.

14. Amines React as Bases
Like ammonia, amines are weak bases in water. NH3 + H2O NH4+ + OH– ammonium ion hydroxide ion CH3—NH2 + H2O CH3—NH3+ + OH– methylammonium ion hydroxide ion

15. Neutralization Forms Amine Salts
An amine salt
forms when amines such as those responsible the odor in fish are neutralized by acid such as citric acid in lemons
is named by replacing the amine part of the name with ammonium, followed by the name of the negative ion

16. Neutralization Forms Amine Salts

17. Properties of Amine Salts
Amine salts are
solids at room temperature
soluble in water and body fluids
the form used for drugs

18. Alkaloids Alkaloids are
physiologically active nitrogen- containing compounds produced by plants such as cocaine
compounds that are alkali-like or have basic characteristics like amines
used as anesthetics, as antidepressants, and in stimulants such as caffeine, and may be habit forming

19. Alkaloids: Cocaine
Cocaine is extracted from plants by reacting them with hydrochloric acid and producing cocaine hydrochloride.
When cocaine hydrochloride is treated with NaOH and ether it is called free-basing. This reaction produces “crack cocaine,” a free amine or free base of the amine.

20. Heterocyclic Amines A heterocyclic amine
is a cyclic compound that contains one or more nitrogen atoms in a ring
typically consists of five or six atoms in the ring with one or more nitrogen atoms

21. Caffeine Caffeine is a stimulant of the central nervous system
is found in coffee beans, tea, chocolate, and soft drinks

22. Nicotine Nicotine increases the adrenaline level in the blood
causes addiction to tobacco

23. Morphine and Codeine Morphine and codeine are alkaloids
obtained from the oriental poppy plant
used as painkillers
modified to make heroin

24. Learning Check Write the structural formula for A. methylpropylamine
B. 2-chloroaniline

25. Solution
A. methylpropylamine CH3–CH2–CH2–NH–CH3
B. 2-chloroaniline