1. Lecture 7: Amines and Amides
18.1
Amines
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2. Amines Amines Are derivatives of ammonia NH3.
Contain N attached to one or more alkyl or aromatic groups.
CH3 CH3
 
CH3—NH2 CH3—NH CH3—N—CH3

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

4. Models of Amines
The three-dimensional models show the shapes of amine molecules with one or more alkyl groups bonded to the nitrogen atom.
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5. Naming Simple 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. IUPAC Names of Amines In the IUPAC system,
Amines are named as alkanamines.
The ­e in the alkane name of the longest chain is changed to ­amine.
The chain is numbered to locate the amine group and substituents.
NH2 |
CH3—CH2—NH CH3—CH—CH3
Ethanamine Propanamine

7. Naming Secondary and Tertiary Amines
In a secondary or tertiary amine,
The longest alkane chain is numbered.
Each alkyl group bonded to the N atom is named as a N-alkyl group
HN—CH3 |
CH3—CH2—CH2—NH—CH3 CH3—CH—CH2—CH3
N-Methyl-1-propanamine N-Methyl-2-butanamine

8. Learning Check Give the common and IUPAC names, and classify as
primary, secondary, or tertiary:
A. CH3—CH2—CH2—NH2
CH3 |
B. CH3—CH2—N—CH3

9. Learning Check Write a structural formula for A. 2-pentanamine
B. N-methyl-1-butanamine

10. Aromatic Amines The amine of benzene is aniline.
Alkyl groups on the N use the prefix N- and the alkyl name.
Aniline chloroaniline N-methylaniline

11. Learning Check Give a name for each: A. CH3—NH—CH2—CH3 CH3 |
B. CH3—CH2—N—CH2—CH2—CH2—CH3 C.

12. Solution A. CH3—NH—CH2—CH3 ethylmethylamine; N-methylethanamine CH3 |
B. CH3—CH2—N—CH2—CH2—CH2—CH3
N-ethyl-N-methyl-1-butanamine
C aniline

13. Lecture 7: Amines and Amides
18.2
Properties of Amines
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14. Boiling Points of Amines, Alcohols, and Alkanes
The boiling points of amines are
Higher than alkanes.
Lower than alcohols of similar mass.
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15. Hydrogen Bonding for Amines
The polar N-H bond
Provides hydrogen bonding in 1°and 2° amines, but not 3°.
In amines is not as polar as the O-H bonds in alcohols.
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16. Solubility in Water Amines are soluble in water
If they have 1-5 carbon atoms.
Because the N atom in smaller amines forms hydrogen bonds with the polar O-H bond in water.
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17. Learning Check Consider the following compounds: 1. CH3—CH2—CH2—NH2
2. CH3—CH2—NH—CH3
3. CH3—CH2—CH2—CH3
A. Which compound has the highest boiling point?
B. Which compound(s) is(are) soluble in water?

18. Solution Consider the following compounds: 1. CH3—CH2—CH2—NH2
2. CH3—CH2—NH—CH3
3. CH3—CH2—CH2—CH3
A. Which compound has the highest boiling point?
1. CH3—CH2—CH2—NH2
B. Which compound(s) is(are) soluble in water?

19. Amines React as Bases Amines are
Bronsted-Lowry bases that attract a H+ from H2O
to the N atom.
Weak bases in water.
NH H2O NH OH–
ammonium hydroxide
CH3—NH2 + H2O CH3—NH OH–
methylammonium hydroxide

20. Neutralization forms Amine Salts
An amine salt
Forms when an amine is neutralized by acid.
Is named by replacing the amine part of the name with ammonium followed by the name of the negative ion.
CH3—NH2 + HCl CH3—NH3+Cl–
methylamine methylammonium chloride
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21. Properties of Amine Salts
Amine salts are
Solids at room temperature.
Soluble in water and body fluids.
The form used for drugs.
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22. Cocaine Cocaine Is sold illegally as an amine salt.
Is reacted with NaOH to produce the free amine form known as “crack”.
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23. Learning Check Write the equation for ethylamine when it reacts with
each of the following:
1. + H2O
2. + HCl

24. Solution Write the equation for ethylamine when it reacts with
each of the following:
1. CH3—CH2—NH2 + H2O CH3—CH2—NH3+ OH–
2. CH3—CH2—NH2 + HCl CH3—CH2—NH3+ Cl–

25. Lecture 7: Amines and Amides
18.3
Heterocyclic Amines and Alkaloids
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26. Heterocyclic Amines A heterocyclic amine Is a cyclic organic compound.
Has a five- or six-atom ring.
Contains one or more nitrogen atoms.

27. Examples of Heterocyclic Amines
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28. Learning Check
Identify the following heterocyclic amines:

29. Solution Identify the following heterocyclic amines: 1. 2. 3.
1. piperidine pyrrole imidazole

30. Alkaloids Alkaloids are
Physiologically active nitrogen-containing compounds.
Produced by plants.
Used as stimulants, anesthetics, and antidepressants.
Often habit forming.

31. Caffeine Caffeine Is a stimulant of the central nervous system.
Is found in coffee beans, tea, chocolate, and soft drinks.
Contains an imidazole ring.
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32. Nicotine Nicotine Increases the adrenaline level in the blood.
Causes addiction to tobacco.
Contains a pyrrolidine ring.

33. Alkaloids Related to Morphine
Such as morphine and codeine are produced by the poppy.
Have been used for centuries as painkillers.
Such as heroin and codeine are modifications of morphine.
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34. Morphine and Codeine Copyright © 2007 by Pearson Education, Inc.
Publishing as Benjamin Cummings

35. Pharmacology An area of research in pharmacology
Is to design drugs such as procaine, lidocaine, and demerol that retain some of the characteristics of alkaloids.
Is to modify the structures of cocaine and morphine to produce anesthesia, but without the addictive side effects.

36. Pharmacology
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37. Learning Check
Identify the heterocyclic amine in serotonin.
serotonin

38. Solution
Identify the heterocyclic amine in serotonin.
pyrrole

39. Lecture 7: Amines and Amides
18.4
Amides
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Publishing as Benjamin Cummings

40. Preparation of Amides Amides are prepared
By reacting a carboxylic acid with ammonia or
an amine (1° or 2°).
Using heat.
O O
 Heat 
CH3—C—OH + NH CH3—C—NH2 + H2O
O O
 Heat 
CH3—C—OH + CH3—NH CH3—C—NH—CH3 + H2O

41. Amides
In amides, an amino group(–NH2) replaces the –OH group of carboxylic acids.
O O
|| ||
CH3—C—OH CH3—C—NH2
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42. Naming Amides Amides are named as alkanamides.
IUPAC replaces –oic acid ending with –amide.
Common names replace -ic acid ending with –amide. O
 Methanamide (IUPAC)
H—C—NH2 Formamide (common)
 Propanamide (IUPAC)
CH3—CH2—C—NH2 Propionamide (common)

43. Naming Amides with N Groups
An alkyl group bonded to the N atom is named as
N-alkyl in front of the amide name.
O H
 │
CH3 —C—N—CH N-methylethanamide (IUPAC)
N-methylacetamide (common)
CH3—CH2 —C—N—CH2—CH3
N-ethylpropanamide (IUPAC)
N-ethylpropionamide (common)

44. Aromatic Amides
The amide of benzene is named benzamide.

45. Learning Check Give the IUPAC and common names for the following: O 
A. CH3–CH2–CH2–C–NH2
O H
 │
B. CH3–C–N–CH2–CH3

46. Solution O  A. CH3–CH2–CH2–C–NH2 butanamide; butryamide O H  │
 │
B. CH3–C–N–CH2–CH3
N-ethylethanamide; N-ethylacetamide

47. Learning Check Draw the structures of A. pentanamide
B. N-methylbutyramide

48. Solution O  CH3–CH2–CH2–CH2–C–NH2 B. N-methylbutyramide
A. pentanamide O 
CH3–CH2–CH2–CH2–C–NH2
B. N-methylbutyramide
CH3–CH2–CH2–C–NH–CH3

49. Classification of Amides
Amides are classified according to the number of carbon atoms bonded to the nitrogen atom.
O H
|| |
CH3—C—N—H Primary (1°) amide
O H
CH3—C—N—CH3 Secondary (2°) amide
O CH3
|| |
CH3 —C—N—CH3 Tertiary (3°) amide

50. Learning Check Give the common and IUPAC names for the following
amides and classify as primary, secondary, or tertiary: O ||
A. CH3—CH2—CH2—C—NH2
O CH3
|| |
B. CH3—C—N—CH2—CH3

51. Solution || A. CH3—CH2—CH2—C—NH2 butryamide (common);
butanamide (IUPAC) primary(1°) amide
O CH3
|| |
B. CH3—C—N—CH2—CH3
N-ethyl-N-methylacetamide (common);
N-ethyl-N-methylethanamide (IUPAC)
tertiary (3°) amide

52. Some Amides in Health and Medicine
Urea is the end product of protein metabolism.
Saccharin is an artificial sweetener.
Some amides such as phenobarbital, Nembutal and Seconal are barbiturates.
Acetaminophen is used to reduce fever and pain.

53. Some Amides in Health and Medicine
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54. Physical Properties of Amides
That are primary (−NH2) or secondary (−NH−) form hydrogen bonds.
That are primary have higher melting points than secondary.
That are tertiary (no H on N) do not form hydrogen bonds and have lower melting points.
All form hydrogen bonds with water.
With 1-5 carbon atoms are soluble in water.

55. Hydrogen Bonding of Amides||
CH3—C—N—H |
H Hydrogen bonding occurs
between primary amides. H

56. Lecture 7: Amines and Amides
18.5
Hydrolysis of Amides
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57. Hydrolysis of Amides acid hydrolysis base hydrolysis
Amides undergo
acid hydrolysis base hydrolysis
carboxylic acid salt of carboxylic acid
ammonium salt and an amine or ammonia

58. Hydrolysis Reactions O || O CH3—C—OH + NH4+Cl– || HCl + H2O CH3—C—NH2
acid hydrolysis O ||
O CH3—C—OH + NH4+Cl–
|| HCl + H2O
CH3—C—NH2
NaOH O
CH3—C—O– Na+ + NH3
base hydrolysis

59. Learning Check N-ethylpropanamide with NaOH.
Write the equation for the hydrolysis of
N-ethylpropanamide with NaOH.

60. Solution N-ethylpropanamide with NaOH. O  CH3—CH2—C—N—CH2—CH3 + NaOH
Write the products of the hydrolysis of
N-ethylpropanamide with NaOH. O 
CH3—CH2—C—N—CH2—CH3 + NaOH
N-ethylpropanamide
CH3—CH2—C—O– Na+ + CH3—CH2—NH2