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Organic Chemistry 6
Molecules with Nitrogen and Their Reactions
IB Topics 10.1.11, 20.1.1, 20.1.2, 20.2.6, 20.4.2, 20.4.5
Reference: Higher Level Chemistry, p. 372-373, p. 399 and 404-405
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Organic Molecules with Nitrogen
There are many types of organic compounds with nitrogen.
We will focus on these three homologous series:
amines
amides
nitriles
2
Amines
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1. Amines
functional group:
amino group
general structure:
R–NH2
N
“R” represents any
hydrocarbon group
general molecular formula:
CnH2n+1NH2
R group
amino
functional
group
(for primary amines)
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1. Amines
Types of Amines
primary
amine
The nitrogen atom is bonded to
ONE carbon atom.
secondary
amine
The nitrogen atom is bonded to
TWO carbon atoms.
tertiary
amine
The nitrogen atom is bonded to
THREE carbon atoms.
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1. Amines
Amines - Condensed Formulas
primary
amine
secondary
amine
tertiary
amine
CH3CH2NH2
CH3 NHCH2CH3
CH3 N(CH3)CH2CH3
(CH3)2NCH2CH3
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1. Amines
Naming Amines
1. base name = stem for # of carbons in the longest chain + anamine
ethanamine
2. secondary amines: name the shorter carbon chain as a branch, and
use N- to identify its location
longest chain = ethanamine
N-methylethanamine
branch = N-methyl
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1. Amines
Naming Amines - continued
3. tertiary amines: name the two shorter carbon chain as branches, and
use N- to identify the location for each branch
branch = N-methyl
branch = N-methyl
longest chain = ethanamine
N,N-dimethylethanamine
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1. Amines
Try These!
Name and classify each amine.
pentanamine (1º)
N-propylbutanamine (2º)
N-ethyl-N-methylpropanamine
(3º)
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Amides
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2. Amides
functional group:
general structure:
amide
O
R C
N
H
H
“R” represents any
hydrocarbon group
H H O
H C C C
H H
R group
N
H
H
amide
functional
group
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2. Amides
Types of Amides
primary
amide
secondary
amide
tertiary
amide
O
R C
N
H
H
O H
R C
O
R C
N R
R
N R
The nitrogen atom is bonded to
ONE carbon atom.
The nitrogen atom is bonded to
TWO carbon atoms.
The nitrogen atom is bonded to
THREE carbon atoms.
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2. Amides
Naming Amides
1. base name = stem for # of carbons in the chain with C=O + anamide
CH3CONH2
ethanamide
2. secondary amides: name the carbon chains on the N atom as a branch, and
use N- to identify its location
branch = N-methyl
N-methylethanamide
base chain = ethanamide
CH3CONHCH3
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2. Amides
Naming Amides - continued
3. tertiary amides: name the two carbon chain on the N atom as branches, and
use N- to identify the location for each branch
branch = N-methyl
branch = N-methyl
base chain = ethanamide
N,N-dimethylethanamide
CH3CON(CH3)2
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2. Amides
Try These!
Name and classify each amide.
H H O
H C C C
H H
N
H
H
propanamide (1º)
N-butylpropanamide (2º)
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Nitriles
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3. Nitriles
functional group:
nitrile
general structure: !
R group
nitrile
functional
group
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3. Nitriles
Naming Nitriles
1. base name = stem for # of carbons in the longest chain + anenitrile
ethanenitrile
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Reactions!
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Reduction of
Reactions
Nitriles
Reduction of NITRILES occurs when hydrogen gas is added.
General equation:
RCN + 2 H2
RCH2NH2
nitrile
Conditions:
catalyst = Ni(s)
amine
+ heat
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Reduction Reactions
Example: Write the equation showing the reduction of propanenitrile.
Name the product. Draw the structures.
CH3CH2CN + 2 H2
CH3CH2CH2NH2
propan-1-amine
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Condensation Reactions
formation of amides
RECALL:
Condensation reactions involve the joining of two small molecules to form one larger
molecule with the loss of a small molecule (such as water).
carboxylic acid + amine
+ H
N
H
R
amide + water
O
R C
N
H
R
+
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Condensation Reactions
example: amide formation
Methanoic acid reacts with ethanamine.
Using structural diagrams, show the condensation reaction.
Name the products that form.
+
Note: Draw the reactants so that the
functional groups are “facing” each other.
+
products
N-ethylmethanamide + water
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