Chapter 13: AMINES-DIAZONIUM SALTS pdf

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ORGANIC CHEMISTRY
Dr Nam T. S. Phan
Faculty of Chemical Engineering
HCMC University of Technology
Office: room 211, B2 Building
Phone: 8647256 ext. 5681
Email:
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Chapter 13: AMINES-DIAZONIUM
SALTS
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NOMENCLATURE OF AMINES
Common names: alkyl + amine
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IUPAC names: alkan + amine
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Substituents are listed in alphabetical order,
regardless of whether they are attached to the
nitrogen or the hydrocarbon
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PREPARATIONS OF AMINES
Alkylation of ammonia
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Gabriel synthesis of primary amines
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Amines by reduction
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Preparation of arylamines
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•

It is possible to selectively reduce just 1 of 2
nitro groups using S
2-
•
H
2
/Pd, Fe/HCl… will reduce both nitro groups
1:1 molar ratio
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Amines
by
reductive
amination
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Amines by Hoffman Rearrangement
Have 1 less
carbon atom
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BASICITY OF AMINES
NOTE:
•
pK
a
of conjugate
acid
•
in water at 25
o
C
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REACTIONS OF AMINES
Reactions
with
primary
amines
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Reactions with secondary amines
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Reactions with carboxylic acid derivatives
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Reactions with alkyl halides
Nucleophilic
substitution
reaction
Excess amine
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The Hofmann elimination reaction
Quaternary ammonium hydroxide formation
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Different from Zaitsev’s product
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Oxidation reactions
Amines can be oxidized by hydrogen peroxide,
peroxyacids, other common oxidizing agents
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Reaction of primary amines with HNO
2

Stable
NOT stable

HNO
2
is unstable, aqueous
NaNO
2
/ acid should be used
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Mechanism:
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Alkyl diazonium salt is NOT stable
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REACTIONS OF DIAZONIUM SALTS
Sandmeyer reactions
KCl, KBr can NOT be used in place of CuCl, CuBr