Amines are organic compounds derived from ammonia by replacing one or more hydrogen atoms with alkyl or aryl groups. Amines are classified as primary, secondary, or tertiary based on the number of alkyl/aryl groups attached to the nitrogen atom. Alkyl amines are more basic than ammonia due to the electron-donating inductive effect of the alkyl groups, which increases the availability of the lone pair on the nitrogen atom. Within alkyl amines, basicity decreases in the order secondary > primary > tertiary. For tertiary amines, steric effects from the three bulky groups decrease basicity. Aromatic amines like aniline are weaker bases than alkyl amines due to the electron-with

1. AMINO COMPOUNDS:

2. Do you know?
AMINO COMPOUNDS :

3. Contents
• Introduction
• Basicity and effect of substituents
• Methods of preparation of Aniline from
Nitrobenzene
• Reactions of amines
with :
acetyl and benzoyl chlorides,
Br2 (aq) and Br2 (CS2 ),
Carbylamine reaction,
Alkylation

4. 4

5. 5

6. Introduction:
(Amines are responsible for the foul smell of dead fish.)
 Amines are stronger bases and better nucleophiles
than other neutral organic compounds.
Defination:
Hydrocarbon derivatives of ammonia (NH3) are
called as amino compounds (amines).
Or
Amines (R-NH2) are organic nitrogen compounds, formed
by replacing one or more hydrogen atoms of ammonia
(NH3) with same number of alkyl groups.
When the hydrocarbon group of an amine is alkyl, cycloallyl
or allyl, it is said to be an aliphatic amine;
while if the hydrocarbon group is aryl, the amine is called an
aromatic amine.

7. Classification of Amines:
7
Amines are also classified as
primary (10),
secondary (20) and
Tertiary (30)
according to number of alkyl group attached to the nitrogen atom.
NR
H
H NR
H
R' NR
R''
R'
N
H3C
H
H
sp3
hybridised
N
H3C
H
CH3
sp3
hybridised
NH3C
CH3
CH3
sp3
hybridised
Methylamine Dimethylamine Trimethylamine
Primary
(1o
)
Secondary
(2o
)
Tertiary
(3o
)

8. 23-8
Structure & Classification
 Amines are further divided into aliphatic,
aromatic, and heterocyclic amines:
• Aliphatic amine: An amine in which nitrogen is bonded
only to alkyl groups.
• Aromatic amine: An amine in which nitrogen is bonded
to one or more aryl groups.
Aniline
(a 1° aromatic amine)
N-Methylaniline
(a 2° aromatic amine)
Benzyldimethylamine
(a 3° aliphatic amine)
NH2 N-H CH2 - N- CH3
CH3 CH3
:
:
:

9. Do you know?
Basic Character of Amines:

10. Structure and bonding
Carbon
Four valence electrons
Four equi. sp3 hybridized orbitals
Each orbital contains one electron
Nitrogen
Five valence electrons
Four equi. sp3 hybridized orbitals
Three orbitals contain one electron each
Fourth orbital contains two electrons

11. Basic Character of Amines:
11
 Amines are basic in nature.
Their basic character is due to presence of lone pair
(unshared pair) of electrons on nitrogen atom due to which
they behave as Lewis base.
Basic strength of the amine depends upon the availability of
lone pair of electrons on nitrogen atom. This lone pair of electrons
is available more easily, and then more is the basicity.
 Any factor that increases the electron density on the
N atom increases an amine’s basicity.
 Any factor that decreases the electron density on N
decreases an amine’s basicity.
Q.1) Discuss / Explain the basic character of Amines. (W-15 & S-16, 2-4 Mark)

12. Basic Character of Amines:
12
NR
H
H
Primary Amine
(1o
)
..
H+
H+
R N
H
H
H
H N
H
H
HNH
H
H
Ammonia
..
More Available
Less Available
R N
H
H
H[ [OR
H N
H
H
H[ [OR
NH2 NH2
....
CH3 NO2
electrons
less available
for bonding
electrons
more available
for bonding
(D) (W)
p-nitroaniline is much weaker base than aniline
Any factor that increases the electron density on the N atom increases an amine’s basicity.
Any factor that decreases the electron density on N decreases an amine’s basicity.

13. Basic Character of Amines:
13
Thus amines react with acids; to form salts.
Amine salts on treatment with a base like NaOH or KOH (OH-), regenerate
the parent amine.
RNH2 + H2O + XRNH3X + OH
..
salt from base
(NaOH / KOH)
Amine
R NH2 H X R NH3 X
NH2
H Cl
NH3Cl
+
Salt
+
Aniline Quaternary Ammonium Chloride
e.g.
..
Amine Acid
..

14. Calculation of Equilibrium constant or
Dissociation constant or Basicity constant (Kb):
14
Aqueous solution of ammonia and amines are alkaline in nature
because of the formation of hydroxide ions (OH-).
Basic character or Base Strength of amines can be explained
in terms of their Kb and pKb values.
Basicity constant is defined
as the concentration of the
products of ionization in
moles per liter divided by
the concentration of the
un-ionised base,
Stronger bases will have higher (larger) values of
basicity constant (Kb) or smaller value of pKb.
R NH2 + H2O
R NH3]
R NH2]
[OH]
[H2O]
R NH3 + OH
K =
pKb = - log Kb
[
[
R NH3]
R NH2]
[OH]
[H2O]K x =
[
[
R NH3]
R NH2]
[OH]
Kb =
[
[
Basicity constant =
Kb Basicity
pKb Basicity
..
..
..
..

15. Relation between Basicity & Kb
15
Stronger bases will have higher (larger) values of
basicity constant (Kb) or smaller value of pKb.
NH3C
H
HNH3C
CH3
CH3
Methyl Amine
(1o
)
Trimethyl Amine
(3o
)
NH
H
H
Ammonia
.. ..
Amines are more basic than ammonia because the electron release (donating) by alkyl groups
increases lone-pair availability.
NH3C
H
CH3
Dimethyl Amine
(2o
)
....
Kb = 6.7 x 10-5
54 x 10-5 37 x 10-5 1.8 x 10-5
Low value High value

16. Structure - Basicity relationship of amines:
16
Basicity of amines is related to their structure.
Basic character of an amine depends upon the formation of the
cation by accepting a proton from the acid.
The more stable the cation is relative to the amine, more basic is
the amine.
NR
H
H
Primary Amine
(1o
)
..
H+
H+
R N
H
H
H
H N
H
H
HNH
H
H
Ammonia
..
More Available
Less Available
R N
H
H
H[ [OR
H N
H
H
H[ [OR

17. LOGO
Alkanamines
Versus
Ammonia:
Q.1) Why alkyl amines are more basic than ammonia? (W-12, 1 Mark)
Q.2) Explain why dimethyl amine [(CH3)2NH] is more basic than methyl amine
[CH3NH2] whereas trimethyl amine [(CH3)3N] is less basic than dimethyl amine
[(CH3)2NH]? (W-12, 2 Mark)
Q.3) Which is the strongest base. (S-13, ½ Mark)
(a) Methyl amine (b) Dimethyl amine (c) Trimethyl amine (d) Ammonia
Q.4) Discuss the relative basic character of ammonia and aliphatic amines.
(W-18, 4 Mark)

18. Alkanamines Versus Ammonia:
Alkyl amines (Aliphatic amines) are more basic
than ammonia:
Aliphatic amines are stronger bases than
ammonia due to +I effect of alkyl groups,
increasing the high electron density on the
nitrogen atom.
18
NR
H
H
Amine
NH
H
H
Ammonia
.. ..
More Available Less Available
Amines are more basic than ammonia because the electron release (donating) by alkyl groups
increases lone-pair availability.

19. Alkylamines are stronger bases than ammonia?
 Due to the electron donating (releasing) nature of alkyl group,
it (R) pushes electrons towards nitrogen and thus makes the
unshared electron pair (lone pair electron) more available for
sharing with the proton of the acid.
 Moreover, the substituted ammonium ion formed from the
amine gets stabilized due to dispersal of the positive charge by
the +I effect of the alkyl group.
19
NR
H
H
Primary Amine
(1o
)
..
H+
H+
R N
H
H
H
H N
H
H
HNH
H
H
Ammonia
..
More Available
Less Available
R N
H
H
H[ [OR
H N
H
H
H[ [OR

20. tertiary amine > secondary amine> primary amine > NH3
 Thus, the basic nature of aliphatic amines should increase with increase
in the number of alkyl groups.
 This trend is followed in the gaseous phase.
 The order of basicity of amines in the gaseous phase follows the expected order:
 tertiary amine > secondary amine> primary amine > NH3.
20
NR
H
HNR
R''
R'
Primary Amine
(1o
)
Tertiary Amine
(3o
)
NH
H
H
Ammonia
.. ..
Amines are more basic than ammonia because the electron release (donating) by alkyl groups
increases lone-pair availability.
NR
H
R'
Secondary Amine
(2o
)
....

21. pramodpadole@gmail.com
Order of Basicity:
Case-I
2o > 1o
Secondary
amines (R-NH2)
are more basic
than Primary
amine
Order
of
Basicity:
Case-II
2o > 1o > 3o
Tertiary amines
are less basic
(weaker base)
than Secondary
and Primary
amine
2o > 1o 2o > 1o > 3o

22. Case-I): 2o > 1o
 Secondary amines (R-NH2) are more basic than Primary
amine.
 These are because of the loan pair of electrons on nitrogen
atom easily available for donation due to the presence of
two electrons donating (releasing) alkyl group.
22
NR
H
H
Primary Amine
(1o
)
..
NR
H
R'
Secondary Amine
(2o
)
..
>
Most basic Least basic

23. Case- II): 2o > 1o > 3o
 Tertiary amines are less basic (weaker base) than
Secondary and Primary amine
23
Least basicMost basic
NR
H
H NR
R''
R'
Primary Amine
(1o
)
Tertiary Amine
(3o
)
NH
H
H
Ammonia
.. ..
NR
H
R'
Secondary Amine
(2o
)
.. ..
> > >
NH3C
H
H NH3C
CH3
CH3
Methyl Amine
(1o
)
Trimethyl Amine
(3o
)
NH
H
H
Ammonia
.. ..
NH3C
H
CH3
Dimethyl Amine
(2o
)
.. ..
Kb 6.7 x 10-554 x 10-5
37 x 10-5 1.8 x 10-5
> > >

24. 2o > 1o > 3o
Why?
3o amine is less basic
than
2o amine & 1o amine

25. Do you know?
Tertiary amines are less basic (weaker base)
than
Secondary and Primary amine

26. Tertiary amines are less basic (weaker base) than
Secondary and Primary amine
Stability of
Ammonium ion:
depends upon the
solvation energy
More is
the solvation energy;
stable are
the ammonium ions.
Steric effect:
3o amines,
There are three bulky alkyl groups
(overcrowding of the three alkyl
groups attached to nitrogen)
These causes steric hindrance due
to this, a protection of nitrogen
of tertiary amine
become relatively difficult.
3o amine
Less basic
than 1o & 2o

27. LOGO
More is the solvation energy; stable are the ammonium ions.
 In the aqueous solution, the substituted ammonium cation gets
stabilized not only by electron releasing effect of the alkyl group (+I) but
also by solvation with water molecules.
 The greater the size of the ion, lesser will be the solvation and the less
stabilized is the ion.
 The orders of stability of ions are as follows:
R N
H
H
H
O H
R N
H
H
R'
R N
H
R'
R''
10 20
30
H
O H
H
O H
H
O H
H
O H
H
O H
H
Greater is the stability of the substituted ammonium cation,
stronger should be the corresponding amine as a base.

28. LOGOOrder of basicity of aliphatic amines
Thus, the order of basicity of aliphatic amines:
Solvation energy primary > secondary > tertiary
Inductive effect tertiary > secondary > primary
Steric Hindrance or effect tertiary > secondary > primary
Least basicMost basic
NR
H
H NR
R''
R'
Primary Amine
(1o
)
Tertiary Amine
(3o
)
NH
H
H
Ammonia
.. ..
NR
H
R'
Secondary Amine
(2o
)
.. ..
> > >

29. 29

30. LOGOBy Dr. P. R. Padole
Arylamines Vs Ammonia:
Q.1) Aniline is a weaker base than methyl amine. (S-12, S-14 & W-16, ½ Mark)
Q.2 Explain: Aniline is a weaker base than aliphatic amines. (S-12, 2 Mark)
Q.3) Explain why, aromatic primary amine is weaker base than aliphatic amine. (W-14, 2 Mark)
Q.4) Explain why: Methyl amine is much stronger base than aniline? (W-16, 2 Mark)
Q.5) Explain why: p-nitroaniline is much weaker base than aniline? (W-16, 2 Mark)
Q.6) Aniline is ________ in nature. (W-17, ½ Mark)
(a) Acidic (b) Basic (c) Neutral (d) Amphoteric
Q.7) The nature of Aniline is: (W-19, ½ Mark)
(a) Acidic (b) Basic (c) Phenolic (d) Neutral

31. LOGO
Arylamines Versus Ammonia:
 Aromatic amines are weaker bases than ammonia
due to the electron withdrawing nature of the aryl group
(benzene ring) by resonance effect (+ R-effect).
31
NH2
Aniline
..
+ H
(Weak Base)
(from Acid)
lone pair of electrons present on N
is Less available or
not easily available for protonation
NH3
Ammonium cation
(Salt)
So, it is weaker than
aliphatic amine
Aromatic Amine
(Stronger Base) (Salt)
NR
H
H
Aliphatic Amine
..
H++ R N
H
H
H
More easily Available

32. LOGO
Arylamines Versus Ammonia:
 In aniline (aromatic amine), -NH2 group is attached
directly to the benzene ring because of that the
lone pair of electrons present on nitrogen atom is
involved in the conjugation with the π-bond of the
benzene ring by + R-effect and thus making it
less available for protonation.
32
NH2
Aniline
..
NH2
Aniline
..
Not easily available for protonation
H+ H N
H
H
HNH
H
H
Ammonia
..
More Available
(Weak base)
(Strong base)
<
lone pair electrons
less available on N atom
lp electrons
easily involved
in the
delocalization

33. LOGO
Arylamines Versus Ammonia:
 Hence aromatic amines are less basic than aliphatic
amines which show no resonance.
 If we write different resonating structures of aniline, we will find that
aniline is a resonance hybrid of the following five structures.
 On the other hand, anilinium ion obtained by accepting a proton can
have only two resonating structures (Kekule structure).
33
NH2 NH2 NH2
I II III
NH2
IV VElectron density on N is less
H N H
[
[
Resonance hybrid




NH2
Aniline
..
+ H
(Weak Base)
(from Acid)
Aromatic Amine
NH3
I
NH3
II
[ [
Two resonating structures

34. LOGO
Arylamines Versus Ammonia:
 We know that greater the number of resonating structures, greater is
the stability. Thus aniline (more resonating structures) is more stable
than anilinium ion. Hence, the proton acceptability or the basic nature
of aniline or other aromatic amines would be less than that of ammonia.
 Hence aromatic amines are less basic than ammonia
which shows no resonance.
In case of substituted aniline, it is observed that electron donating (releasing) groups (D)
like –OCH3, –CH3 increase basic strength
whereas electron withdrawing groups (W) like –NO2, –SO3H, –COOH, –X
decrease the basic strength (basicity) of aromatic amines.
34
NH2 NH2
....
CH3 NO2
electrons
less available
for bonding
electrons
more available
for bonding
(D) (W)
p-nitroaniline is much weaker base than aniline

35. LOGO
Preparation of Aniline from Nitrobenzene:
Reduction of Nitrobenzene:
Aniline

36. LOGO
Preparation of Aniline from Nitrobenzene:
 Reduction of Nitro compounds:
When nitrobenzene is reduced by the reducing
reagent like,
(i) H2 in the presence of Ni, Pd or Pt as catalyst,
(ii) Zn or Fe or Sn and HCl;
(iii) Lithium Aluminum hydride (LiAlH4); to form aniline.
36
Aniline
Q.1) Explain: Conversion of nitrobenzene to aniline using Ni catalyst. (S-12, 2 Mark)
Q.1) How will you prepare the Aniline from nitrobenzene? (W-14, 2 Mark)
NO2 NH2(i) H2 / Ni or Pd or Pt as catalyst
(ii)Zn/HCl or Fe/ HCl or Sn/HCl
(iii) LiAlH4
Aniline
Nitrobenzene
+ 6 [H] + 2 H2O
Reduction by
or
3 H2

37. LOGOElectrophilic Substitution in the Ring:
The amino group (-NH2) activates the benzene ring by
resonance mechanism (+R-effect) and the ortho–para
positions are centers of high electron density.
37
Q.1) In aniline electophilic substitution occurs at: (S-15, ½ Mark)
(a) Ortho-para (b) Meta (c) All positions (d) None of these.
NH2 NH2 NH2
I II III
NH2
IV VElectron density on N is less
H N H
[
[
Resonance hybrid





38. LOGOAniline

39. Chemical Reactions of Aniline:
AnilineAcetanilide
Benzanilide
Phenyl
isocyanide
N-methyl
aniline
Br2
Aqueous Br2Br2 in CS2
2,4,6-
tribromoaniline
Ortho & para-
bromoaniline
1Reaction with
Acetyl chloride
Or Acetic anhydride
Reaction with
CHCl3 and
alco. KOH

40. LOGO
(i) Preparation of Acetanilide from Aniline:
Or
Action of Acetyl Chloride or Acetic Anhydride
on Aniline:
Or
Reaction with Acetyl chloride:
Acylation Reaction
Q.1) Explain the Conversion of aniline to Acetanilide. (W-13, 2 Mark)
Q.2) How does aniline react with Carbonyl chloride? (W-16, 2 Mark)
Q.3) How will you prepare Acetanilide from Aniline? (S-17, 2 Mark)
Q.4) What happen when Aniline is treated with Acetyl chloride? (W-19, 2 Mark)

41. LOGO
Preparation of Acetanilide from Aniline:
 Reaction with Acetyl chloride (Acylation Reaction):
When aniline is reacted with acetyl chloride (or acetic anhydride);
to form acetanilide.
41
N
H
H
Cl C CH3
O
C CH3
O
N
H
Aniline
+
Acetanilide
Acetyl chloride + HCl
OR
N
H
H
C
O
C CH3
O
N
H
Aniline
+
AcetanilideAcetic anhydride
+ CH3COOH
CH3
C
O
CH3
O
gacial
CH3COOH

42. LOGO
Q.1) How will you convert Aniline to benzanilide? (S-12, S-13, W-13, S-14, W-14, S-15, W-15 & W-18, 2 M)
Q.2) Complete the following reaction. (W-16, 2 Mark)
Q.3) How will you prepare Benzanilide from Aniline? (S-17, 2 Mark)
(ii) Action of Benzoyl chloride:
Or Preparation of Benzanilide from Aniline:
Or Reaction with Benzoyl chloride:
NH2
COCl
NaOH
?

43. Preparation of Benzanilide from Aniline:
Reaction with Benzoyl chloride:
When aniline is reacted with benzoyl chloride in
presence of NaOH; to form benzanilide.
 This reaction is called Benzoylation Reaction.
43
N
H
H
Cl C C6H5
O
C C6H5
O
N
H
Aniline
+
BenzanilideBenzoyl chloride
+ HCl
NaOH

44. LOGO
Alkyl halides (Alkylation):
Reaction with
Preparation of N-methyl aniline:
Preparation of N-dimethyl aniline:
Preparation of Quaternary ammonium iodide:
Aniline

45. Reaction with Alkyl halides
(Alkylation Reaction):
 When Aniline is heated with methyl iodide under
pressure; to form N-methyl aniline (20 amine),
which is then converted to dimethyl aniline (30
amine) and finally to quaternary ammonim iodide
(salt).
45
Q.1) How will you obtain N-methyl aniline form Aniline? (S-17 & W-19, 2 Mark)
N
H H
N
CH3 H
N
CH3
CH3CH3N
CH3 CH3
Aniline
N-Methyl aniline
+ CH3-I
Quaternary ammonium
Iodide
N-Dimethyl
aniline
I
- HI - HI
.. .. ..
+ CH3-I + CH3-I

46. Do you know?
Carbylamines Reaction

47. Carbylamines Reaction
(Isocyanides Test):
47
Or Preparation of Phenyl isocyanide from Aniline
by Carbylamine Reaction:
Q.1) How will you convert Aniline to phenyl isocyanide by Carbylamine reaction? (S-12 & S-14, 2 Mark)
Q.2) How will you convert Aniline to phenyl isocyanide? (S-13 & S-15, 2 Mark)
Q.3) Explain the Carbylamine reaction of aniline. (W-13 & S-15, 2 Mark)
Q.4) How will you prepare phenyl isocyanide from aniline? (W-17, 2 Mark)
Q.5) What happen when Aniline is treated with Chloroform and alcoholic KOH? (W-19, 2 Mark)
Q.6) The reaction of aniline with chloroform and alcoholic caustic potash solution is
called as Carbylamines reaction
When aniline is reacted with chloroform (CHCl3) and
alcoholic KOH solution (caustic potash solution); to form
phenyl isocyanide (phenyl carbylamines).
Aniline
NH2
+
Phenyl isocyanide
Alcohol
NC
CHCl3 + 3 KOH + 3 KCl + 3 H2O

48. Reaction with Bromine (Br2):
Reaction with
aqueous Bromine:
Or
Preparation of
2,4,6-tribromo
Aniline
from Aniline:
Bromine
Br2
Reaction with
Bromine in CS2 :
Or
Preparation of
ortho and para-
bromo Aniline
from
Aniline:

49. Reaction with aqueous Bromine:
Or Preparation of 2,4,6-tribromo Aniline from Aniline:
 When Aniline is reacted with aqueous solution of
Bromine (Br2); to form 2,4,6-tribromoaniline.
Q.1) What happens when aniline is treated with aqueous Br2? (S-17 & S-18, 2 Mark)
Q.2) How will you prepare 2,4,6-tribromoaniline from Aniline? (W-17, 2 Mark)
Q.3) Complete the following reaction and predict the product: (S-19, 2 Mark)
NH2
NH2
Br Br
Br
Aniline
+ 3 Br2 (aq)
2,4,6-Tribromoaniline (White ppt)
H
H
H
+ 3 HBr
Br----Br
Br----Br
Br----Br
?
NH2
+ Br2(aq)

50. Reaction with Bromine in CS2 :
Or Preparation of ortho and para-bromo Aniline from Aniline:
 When Aniline is treated or reacted with Bromine (Br2) in Carbon
disulphide (CS2); to form mixture of ortho and para-bromo aniline
(2-bromoaniline and 4-bromoaniline).

Q.1) How does aniline react with Carbon disulphide (CS2)? (W-16, 2 Mark)
Q.2) What happens when aniline is treated with Br2 in Carbon disulphide (CS2)?
(S-17 & S-18, 2 Mark)
Q.3) How will you prepare ortho and para bromoaniline from aniline? (W-17, 2 Mark)
NH2 NH2
Br
NH2
Br
Aniline
+
2-Bromoaniline
(o-bromo aniline)
in CS2
+
4-Bromoaniline
(p-bromo aniline)
Br2

51. LOGO
Hoffmann’s Exhaustive Methylation:
Hoffmann’s Degradation or
Hoffmann’s Rearrangement:
Q.1) Explain Hoffmann’s exhaustive methylation for opening of heterocyclic ring.
(S-14, 4 Mark)
Q.2) Explain Hoffmann’s exhaustive methylation with mechanism.
(S-15 & S-16, 4 Mark)
Q.3) Explain Hoffmann’s exhaustive methylation reaction. (S-19, 4 Mark)

52. www.themegallery.com
Hoffmann’s Exhaustive Methylation:
Hoffmann’s Degradation or Hoffmann’s Rearrangement:
The complete process of converting an amine (10, 20 or 30),
to an unsaturated compound by the pyrolytic decomposition
(by heating) of the quaternary ammonium hydroxide
(obtained by treating amine with the excess of methyl
iodide and then hydrolyzing the resulting quaternary
ammonium iodide with moist silver oxide) is called the
Hoffmann’s Exhaustive Methylation or the Hoffmann’s
Degradation or Hoffmann’s rearrangement.
52
C
H
C
NH2
CH3I
C
H
C
N(CH)3 I
C
H
C
N(CH3)3OH
C C + N(CH3)3 H2O
(excess)
Moist
Ag2O Heat
+
Amine
(1o
, 2o
or 3o
)
unsaturated
compound
Hydrolysis Decomposition

53. www.themegallery.com Mechanism of Hoffmann’s Exhaustive Methylation:
Step-1) Reaction with excess of Methyl iodide by SN2 reaction:
 The conversion of an amine (10, 20 or 30) to quaternary
ammonium iodide by treating the amine with excess of methyl
iodide is an SN2 reaction, here the amine is the incoming
nucleophile and iodine is the leaving nucleophile.
Step-2) Reaction with moist silver oxide is a simple ion-exchange reaction:
 The conversion of the quaternary ammonium iodide to quaternary
ammonium hydroxide by the action of moist silver oxide is a simple
ion-exchange reaction.
53
Amine
(1o
, 2o
or 3o
)
C C N
H H
H
CH3 I C C N
H H
H
C C N
H H
H
CH3 C C N
H CH3
CH3
CH3CH3
: +
 + CH3I
excess

I II
quaternary ammonium iodide
 
C C N
H CH3
CH3
CH3 I
quaternary ammonium iodide
C C N
H CH3
CH3
CH3+ Ion exchange reaction
+AgOH OH AgI
Moist
Ag2O
quaternary ammonium hydroxide

54. www.themegallery.com Mechanism of Hoffmann’s Exhaustive Methylation:
Step-3) Pyrolytic decomposition; to form unsaturated compound:
 The pyrolytic decomposition of the quaternary ammonium
hydroxide to an unsaturated compound, water and 30 amine is a
-elimination reaction which usually follows the E2 pathway;
and so the Hoffmann’s product are usually obtained in the pyrolytic
decomposition of quaternary ammonium hydroxide.
54
C C N
H CH3
CH3
CH3 OH
quaternary ammonium hydroxide
C C N
H CH3
CH3
CH3 C C N
CH3
CH3
CH3+ +
HO
H2O
Pyrolytic
decomposition
By E2
elimination reaction
:
unsaturated
compound

55. 55