Chapter 15
 Amines
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-derive from ammonia
-one or more of the hydrogen atoms have been
replaced by an organic group
-pyramidal in structure
-1° amine indicates 1 H replaced
-2° amine indicates 2 H’s replaced
-3° amine indicates 3 H’s replaced
The N atom is more electronegative than the H
so the N-H bond is polar
 Amines
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amines can bond to each other through hydrogen
bonding and can also bond to water molecules
1° amines have higher boiling points than alkanes
but lower boiling points than alcohols of similar
molar mass
3° amines cannot bond to other amines because
there is no H available to bond
3° amines have much lower boiling point than 1°
and 2° amines of similar molar masses
 Amines
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H bonds between amines not as strong as those in
alcohols because the N is not as electronegative
as the O.
1° and 2° amines have a lower boiling point than
alcohols
All can form H bonds with water at the N
Small amines are soluble in water (6 carbons or
less)
Solubility decreases as the carbon chain
increases
 Amines

1. Determine the name of the parent compound
(the longest continuous carbon chain containing
the amine group)
2. Replace the –e ending from the alkane parent
with –amine

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
IUPAC
Ex. Ethane becomes ethanamine
3. Number the parent chain so that the carbon
with the amine group has the lowest number
4. Name and number any substituents and add
them as prefixes
 Example
2-pentanamine
 For
2° and 3° amines, the prefix N-alkyl is
added (just add the letter N)
 Example
N,N-Dimethylpropanamine
A
simple benzene ring with an amine is
benzenamine (aniline)
 See pg 499 with methyl group
 If other groups are attached to the N group,
use the letter N- followed by the name of the
group
N-methyl-1-phenyl-2-propanamine
 Amines
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
Common names
-used for simple amines
-use the common names of alkyl groups bonded
to the amine and the ending –amine
-list alphabetically if multiple
Dimethyl amine
Ethylmethylamine
 Amphetamines




(benzedine, methadrine)
-stimulates the central nervous system, elevate
blood pressure and pulse rate, decrease fatigue
-used to treat depression and epilepsy
-found in diet pills (decrease appetite)
-controlled federally because excessive use can
cause mental illness and paranoia
 Analgesics
(demerol)- pain relief
 Anesthetics (novocaine)- pain blocker
 Ephedrine



-decongestant in cough syrup and nasal spray
-sales of ephedrine and pseudoephedrine are now
behind the counter
-pharm. companies replacing these with
phenylephrine
 Preparation
of amines
 In a lab setting, they are prepared by reducing
amides into a nitro compound.
 1° amines are created by reducing a nitro
compound with a reducing agent
 Ex. Nitrobenzene is reduced to aniline
The symbol [H] is
often used to show
that any reduction
agent can be used.
 1°,
2°, 3° amines are produced when amides
are reduced
 If the N on the amide has 2 hydrogen atoms,
a 1° amine is produced
 If there is 1 H and 1 organic compound, a 2°
amine is produced
 If both are organic compounds, a 3° amine is
produced
See page 503 for 3 different reactions
 Basicity
 When
dissolved in water, an amine will
accept an H+ ion and become a weak base.
 The lone pair from the N bonds with the H+
ion making an alkylammonium ion. Hydroxide
ions are also produced.
 Creates a base solution.
You do not need to know the reaction. You
need to know why amines act as bases.
 -Formed
from the reaction between a
carboxylic acid derivative and either
ammonia or an amine.
 -Composed of a carbonyl group (from the
carboxylic acid) and an amino group (from
the ammonia or amine)
 Amide
bond- bond between the carbonyl
carbon and the N that contains the amine or
ammonia
 -Most
are solid at room temp.
 -very high boiling points (due to strong H
bonds between amides)
 -simple amides are soluble in water (due to
strong H bonds between amides)
 -cannot become basic like amines (do not
accept H+ in water)
 -there is a strong attraction between the O
of the carbonyl group and the lone pair of
the N which does not allow it to hold the H+
(this attraction creates a resonance hybrid)
 Amides
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Both IUPAC and Common come from the IUPAC
and Common names of the carboxylic acids from
which they are made.
-Remove –ic acid ending from the common name
or –oic acid of IUPAC name of carboxylic acid
-Replace with –amide
Propanamide
N-Propylbutanamide
 See
table 15.4 for IUPAC to Common
comparisons
 Substituents
on the N are placed as prefixes
 -indicated by N- followed by the substituent
name
 -no spaces between prefix and amide name
 Barbiturates


(barbital)
-“downers”
-used as sedatives, anticonvulsants for epileptics,
brain disorders
 Acetaminophen
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

-used in place of aspirin
-found in Tylenol
-relieves pain, reduces fever
 Phenacetin
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
-pain reliever created in 1887
-banned in 1083 due to cause of kidney damage and
blood disorders
 Preparation
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of Amides
-prepared from carboxylic acid derivative (either
acid chlorides or acid anhydrides)
Recall: Acid chlorides are made from carboxylic
acids that react with a reagent like PCl5
Acid chlorides react rapidly with ammonia or
amines
2 moles of ammonia or amines needed in a
reaction
 Type
of reaction- Acyl group transfer reaction
 Acyl group- found on the acid chloride
 -transferred from the Cl to the N of one of
the ammonia/ amine molecules
 -the 2nd reacts with the HCl that forms from
the transfer to create ammonium chloride or
alkyl-ammonium chloride
See reaction page 513
 The
reaction between acid anhydride and 2
moles of ammonia/ amine is also an acyl
group transfer reaction.
 See reaction page 514
 Commercial
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Amide
-aspartame
-artificial sweetener
-made from 2 amino acids (aspartic acid and
phenylalanine) joined by an amide bond