1. Chapter Seventeen
Amines and Amides

2. Amines and Amides
Parachutist with a parachute made of the polyamide nylon.
© Royalty-Free / CORBIS

3. Nitrogen
The four most abundant elements in organic compounds are carbon, hydrogen, oxygen, and nitrogen
Element
Valence Electrons
Bonds for an Octet
Carbon 4
Hydrogen 1
Oxygen 6 2
Nitrogen 5 3

4. Amines Organic compounds of nitrogen N
Classified as primary, secondary, tertiary
NH2 = amino group
CH CH3
 
CH3—NH2 CH3—NH CH3—N — CH3
______ _______ ________

5. Amines and Amides cont’d
Fig. 17.1
Classification of amines is related to the number of R groups attached to the nitrogen atom.

6. Naming Amines
Classified as primary (RNH2), secondary (R2NH), or tertiary (R3N). Different than alcohols.
primary amine
secondary amine
tertiary amine
primary ROH
secondary ROH
tertiary ROH

7. Amines and Amides cont’d
Aniline, the simplest aromatic amine. Aromatic amines are generally toxic.

8. Naming Primary Amines
Identify the parent chain: the longest chain of carbons to which the nitrogen is attached
Replace the “-e” ending of the alkane name with “-amine”
Number the parent chain from the end closest to the nitrogen atom
Identify the position of the nitrogen atom with a number
Identify any substituents and their locations

9. Name the Following Amines
cyclohexanamine
2-propanamine
1,4-butanediamine or
1,4-diaminobutane

10. Naming Secondary and Tertiary Amines
Base name involves longest carbon chain attached to the nitrogen
Other groups attached to the nitrogen have “N-” in front of the substituent names
N-ethyl-N-methyl-ethylamine
N-ethyl-N-methyl-cyclohexylamine

11. Amines and Amides cont’d
Amine-amine hydrogen bonding.

12. Amines and Amides cont’d
Low-molecular amines are soluble in water because of amine-water hydrogen bonding interactions.

13. Amines and Amides cont’d
Ammonium ion has a tetrahedral structure, as does the quaternary ammonium ion.

14. Amines and Amides cont’d
Fig. 17.8
Heterocyclic amines serve as “parent” molecules for more complex amine derivatives.

15. Amines and Amides cont’d
Methoxyamphetamine Isopreternol

16. Basicity of Amines
Like ammonia, amines act as weak __________ in water
_____________ are proton acceptors
When amines react with water, the products are a hydroxide ion and a substituted ammonium ion
Substituted ammonium ion: an ammonium ion in which one or more alkyl, cycloalkyl, or aryl groups have been substituted for hydrogen atoms
CH3NH H2O CH3NH OH–
methylammonium hydroxide
Treating an amine salt with a strong base regenerates the amine

17. Neutralization Forms Amine Salts
Neutralization with _______ gives ammonium salt
CH3NH HCl CH3NH3+ Cl–
methylammonium chloride
Amine salts are named by replacing the “amine” part of the name with “ammonium” followed by the name of the negative ion

18. Properties of Amine Salts
Amine salts are:
Solid at room temperature
Soluble in water and body fluids
The form used for drugs
Ephedrine Hydrochloride Ephedrine HCl Sudafed
Diphenhydramine hydrochloride Diphenhydramine HCl Benadryl

19. Other Amine Salts Cocaine is sold illegally as an amine salt
Cocaine is reacted with NaOH to produce the free amine form, known as “crack” O C H 3 N +
Cl- O C H 3 N
Cocaine (“free base”)
Cocaine Hydrochloride

20. Amines vs. Amides Amides have carbonyl groups next to the nitrogen.
Amines have alkyl groups or hydrogens bonded to the nitrogen.
amide
amine

21. Classification of Amides
Classification depends on the number of alkyl groups connected to the amide nitrogen atom

22. Amines and Amides cont’d
Models of the simplest primary, secondary, and tertiary amides.

23. Amines and Amides cont’d
The high boiling point of amides are related to the numerous amide-amide hydrogen bonding possibilities that exist.

24. Classify each as amine or amide.

25. Amines and Amides cont’d
CC 17. 5

27. Alkaloids Physiologically active nitrogen-containing compounds
Obtained from ____________
Used as anesthetics, antidepressants, and stimulants
Many are ______________

28. Nicotine

29. Caffeine

30. Procaine

31. Preparations of Amines
Amines can be prepared by adding an alkyl halide to ammonia in the presence of base
Two step process: alkylation to produce the salt; reaction with NaOH to produce the amine
NH3 + R-X  R-NH3+Cl-
R-NH3+Cl- + NaOH  RNH2 + NaX + H2O

32. Preparation of Amines Ammonia + alkyl halide + NaOH primary amine
Primary amine+ alkyl halide + NaOH  secondary amine
Secondary amine+ alkyl halide + NaOH  tertiary amine
tertiary amine + alkyl halide  quaternary
ammonium salt

33. Alkylation Reactions

34. Preparation of Amides
Amides are produced by reacting a carboxylic acid with ammonia or an amine (primary or secondary)
“Amidification Reactions”
Dehydration Reaction 
H2O

35. Amidification Reactions
Ammonia + carboxylic acid  primary amide
Primary amine + carboxylic acid 
secondary amide
Secondary amine + carboxylic acid  tertiary amide

36. Reactions of Amides Amides undergo acid hydrolysis base hydrolysis
carboxylic acid salt of carboxylic acid
ammonium salt and an amine or ammonia

37. Reactions of Amides acid hydrolysis O  O HCl + H2O CH3COH + NH4+Cl–
CH3CNH O
NaOH 
CH3CO– Na+ + NH3
base hydrolysis