Announcements & Agenda (04/02/07)
Pop Quiz Right Now!
Quiz on Wednesday (Chirality & Ch 13)
Will hand HW practice in lab
Today
 Esters (13.3)
 Amines (13.4)
 Amides (13.5)
1
Last Time: Drawing Fischer Projections
2
Last Time: Carboxylic Acids
Carboxylic acids
• are weak acids.
• ionize in water to produce carboxylate
ions and hydronium ions.
O
║
CH3−C−OH + H2O
O
║
CH3−C−O– + H3O+
~1%
Also: Neutralization Reactions! Esterification!
3
Ester Products
Aspirin
• is used to relieve pain
and reduce inflammation.
• is an ester of salicylic
acid and acetic acid.
Oil of wintergreen
• is used to soothe sore
muscles.
• is an ester of salicylic
acid and methanol.
O
C OH
O
O C CH3
O
C O CH3
OH
4
Naming Esters
The name of an ester contains the names of
• the alkyl group from the alcohol.
• the carbon chain from the acid with –ate ending.
methyl
ethanoate (acetate)
O

-oate: means
CH3— O—C —CH3
ester present
IUPAC: methyl ethanoate
common: methyl acetate
5
Esters in Plants
Esters give flowers and fruits their
pleasant fragrances and flavors.
6
Acid Hydrolysis of Esters
• an ester reacts with water to produce a
carboxylic acid and an alcohol.
• an acid catalyst is required.
O

H+
H—C—O—CH2—CH3 + H2O
O

H—C—OH
+ H—O—CH2—CH3
7
Base Hydrolysis (Saponification)
• is the reaction of an ester with a strong base.
• produces the salt of the carboxylic acid and an
alcohol.
O
||
CH3—C—O—CH2—CH3 + NaOH
O

CH3—C—O– Na+ + HO—CH2—CH3
salt of carboxylic acid
alcohol
8
Last Time: Base Hydrolysis of
Triglycerides Make Soaps
9
Carboxylic acids with lots of carbons are fatty
acids (usually even #, 10, 12, 14, 16, 18)
Sodium salts of fatty
acids are soaps.
10
Cleaning Action of Soap
A soap
• contains a nonpolar
end that dissolves in
nonpolar fats and oils,
and a polar end that
dissolves in water.
• forms groups of soap
molecules called
micelles that dissolve in
water and are washed
away.
11
Learning Check
Write the organic products when methyl acetate
reacts with
A. water and an acid catalyst.
O

CH3—C—OH + HO—CH3
B. KOH.
O

CH3—C—O– K+
+ HO—CH3
12
13.4 Amines (Derivatives of NH3)
Typically 3 kinds:
• Primary (1°) amines: 1 carbon group is bonded to N
• Secondary (2°) amines: 2 carbon groups bonded to N
• Tertiary (3°) amines: 3 carbon groups bonded to N.
H
|
CH3—N—H
1°
CH3
|
CH3—N—H
2°
CH3
|
CH3—N—CH3
3°
Quaternary (4°) amines also possible (4 C groups attached
to nitrogen atom)
13
Naming Amines (No need to memorize)
• Simple amines are named as alkylamines.
• Names of alkyl groups bonded to the N atom listed in
alphabetical order in front of amine.
CH3—CH2—NH2
ethylamine
CH3—NH—CH3
dimethylamine
CH3
|
CH3—N—CH2—CH3 ethyldimethylamine
14
Hydrogen Bonding for Amines
• N-H bond provides hydrogen bonding in
1°and 2° amines, but not in 3° amines.
• is not as polar as the O-H bonds in alcohols.
•
H-bonding not as good 
15
Solubility in Water
• Amines with 1-5 carbon atoms are soluble in water.
• Form hydrogen bonds with the polar O-H bond in
water.
16
Amines React as Bases
Like ammonia, amines are weak bases in water.
NH3 + H2O
NH4+ + OH–
ammonium hydroxide
CH3—NH2 + H2O
CH3—NH3+ + OH–
methylammonium hydroxide
17
Neutralization forms Amine Salts
An amine salt
• forms when an amine is
neutralized by acid.
CH3—NH2 + HCl
Cl–
methylamine
CH3—NH3+
methylammonium chloride
18
OK so far???
1. Yes
2. No
3. Kinda…
0%
0%
0%
1
2
3
4
5
19
Properties of Amine Salts
•
•
•
•
solids at room temperature.
soluble in water and body fluids.
the form used for drugs.
DON’T STINK!
20
Alkaloids
• physiologically active
nitrogen-containing
compounds.
• obtained from plants.
• used as anesthetics,
antidepressants, and in
stimulants such as
caffeine.
• often addictive.
21
Cocaine
• sold illegally as the amine salt.
• reacted with NaOH to produce the free
amine form known as “crack.”
22
Caffeine and Nicotine
Caffeine
• is a stimulant of
the central
nervous system
Nicotine
• increases adrenaline
level in blood
N
CH 3
23
Morphine and Codeine
• alkaloids.
• obtained from the
oriental poppy plant.
• used as painkillers.
• modified to make
heroin.
24
Amides 13.5
• In amides, an amino group(–NH2) replaces the –OH
group of carboxylic acids.
O
||
CH3—C—OH
O
||
CH3—C—NH2
25
Preparation of Amides
Amides are produced
• by reacting a carboxylic acid with ammonia
or an amine (1° or 2°).
• using heat.
O

Heat
CH3—C—OH + NH3
O

CH3—C—NH2 + H2O
O
O

Heat

CH3—C—OH + CH3—NH2
CH3—C—NH—CH3 + H2O
26
Some Amides in Health and Medicine
27
Physical Properties of Amides
SIMILAR TO AMINES…
• primary (−NH2) or secondary (−NH−) amides
form hydrogen bonds.
• primary have higher mp’s than secondary.
•
tertiary (no H on N) do not form hydrogen bonds &
have lower melting points.
• all form hydrogen bonds with water.
• with 1-5 carbon atoms are soluble in water.
28
Hydrogen Bonding of Amides
O
||
CH3—C—N—H
|
H
Hydrogen bonding occurs
between primary amides.
O
||
CH3—C—N—H
|
H
29
Hydrolysis of Amides
IMPORTANT TO KNOW
Amides undergo
• Acid hydrolysis to produce a carboxylic
acid and an ammonium salt.
• Base hydrolysis to produce the salt of a
carboxylic acid and an amine or ammonia.
• REACTIONS LOOK SIMILAR TO THOSE
OF ESTERS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
30
Hydrolysis Reactions
acid hydrolysis
O
||
CH3—C—NH2
O
||
CH3—C—OH + NH4+Cl–
HCl + H2O
NaOH
O
||
CH3—C—O– Na+ + NH3
base hydrolysis
31