1. Amines - classification
quaternary ammonium salts 3o

2. Nomenclature
To name aliphatic amines, name the alkyl groups bonded to the amine nitrogen and then add the suffix “amine”:
(CH3)3CNH2
C2H5NHCH3
ethylmethylamine
t-butylamine
Systematic nomenclature adds the suffix to the name of the hydrocarbon:
CH3CH2NH2
C2H5NHCH3
ethanamine
N-methylethanamine

3. Nomenclature
In the IUPAC system, the -NH2 group is called the amino group. The prefix “amino” (or “methylamino”, “diethylamino” etc.) is therefore used in naming complex molecules.
4-aminobutanoic acid
-aminobutyric acid
H2NCH2CH2CH2CO2H
H2NCH2CH2OH
2-aminoethanol
ethanolamine
2-methylaminoheptane

4. Nomenclature m-nitroaniline 3-nitrobenzenamine N-ethyl-N-methylaniline
N-ethyl-N-methylbenzenamine

5. Nomenclature
Salts of amines are named by replacing the suffix amine by ammonium:-
ethylammonium sulfate
trimethylammonium nitrate
anilinium chloride

6. Physical Properties
Tertiary amines, having no N-H bonds, cannot form hydrogen bonds (N-H H).
1o and 2o amines can! Their intermolecular association by hydrogen bonding reduces their volatility relative to hydrocarbons of similar molecular weight.
Amines having less than six carbon atoms show an appreciable water solubility.

7. Preparation - alkylation

8. Preparation - reduction of nitro compounds
1º amine

9. Preparation - reductive amination
amphetamine

10. Preparation - reduction of nitriles

11. Preparation - Hofmann degradation
phentermine - an appetite suppressant

12. Hofmann degradation

13. Reactions - basicity
stronger base
weaker base

14. Reactions - basicity
Kb: CH3NH2 = 4.75x10-4, NH3 = 1.78x10-5, C6H5NH2 = 4.26x10-10

15. Reactions - basicity
Kb: CH3NH2 = 4.75x10-4, NH3 = 1.78x10-5

16. Reactions - basicity

17. Reactions - basicity

18. Substituent effects
Substituents attached to the aromatic ring which are electron attracting reduce the basicity of amines.
Electron-repelling substituents increase amine basicity.

19. Action of nitrous acid +
1. NaNO /H 2
RNH
ROH 2 2. H O/ D 2

20. Aromatic diazonium salts

21. Sandmeyer reaction

22. Gattermann reaction

23. Aromatic diazonium salts

24. Aromatic diazonium salts
Synthesis of phenols
Substitution by H

25. Synthesis of the three bromotoluenes
oops

26. Synthesis of the bromotoluenes

27. Synthesis of m-bromotoluene

28. Coupling Reactions of Diazonium Compounds
An electrophilic attack......
p-(dimethylamino)azobenzene

29. congo red

30. Preparation of substituted amides

31. Preparation of substituted amides

32. Nomenclature of Substituted Amides

33. Sulfanilic acid ? mp > 280-300o OH- - soluble
H+ - insoluble
dipolar ion - a zwitterion
“zwitter” - hermaphrodite

34. Sulfa drugs
sulfanilimide

35. Spectroscopic Properties
N-H - stretching cm-1
1o amines show 2 high intensity peaks
NMR - the amino H gives a peak which can be found almost any where in the spectrum (similar to the -O-H proton).

36. Problems
Try problems (a) - (d), (a) - (e), (a) - (e), 20.24, 20.26, 20.30, 20.31, 20.37, 20.38, 20.39, 20.44, and