Ch 06 Amines and Amides - Angelo State University

44 Pages·2006·1.89 MB·English

Chapter 6 Notes
CCHHEEMM 22335533
FFuunnddaammeennttaallss ooff OOrrggaanniicc CChheemmiissttrryy
CChhaapptteerr
66 AAmmiinneess aanndd AAmmiiddeess
Organic and Biochemistry for Today(4th ed.)
Spencer L. Seager / Michael R. Slabaugh
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NNiittrrooggeenn--CCoonnttaaiinniinngg FFuunnccttiioonnaall GGrroouuppss
• Nitrogen is in Group V of the periodic table, and in
most of its compounds, it has three single bonds and
one lone pair:
N
• In this chapter, we will take a look at two functional
groups which contain nitrogen atoms connected to
carbons: the amines and the amides.
O
R N R'' R C N R'
R' R"
Amine Amide
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Chapter 6 Notes
CCllaassssiiffiiccaattiioonn aanndd
NNoommeennccllaattuurree ooff AAmmiinneess
3
AAmmiinneess
• Amines and amides are abundant in nature. They
are a major component of proteins and enzymes,
nucleic acids, alkaloid drugs, etc. (Alkaloids are N-
containing, weakly basic organic compounds;
thousands of these substances are known.)
• Amines are organic derivatives of ammonia, NH , in
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which one or more of the three H’s is replaced by a
carbon group.
• Amines are classified as primary (1°), secondary
(2°), or tertiary (3°), depending on how many
carbon groups are connected to the nitrogen atom.
H N H R N H R N H R N R''
H H R' R'
Ammonia 1°Amine 2°Amine 3°Amine
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Chapter 6 Notes
EExxaammpplleess:: CCllaassssiiffyyiinngg AAmmiinneess
• Classify the following amines as primary (1°),
secondary (2°), or tertiary (3°).
H CH NH
3 2
CH CH CH N H CH N CH CH CH CHCH
3 2 2 3 3 3 2 3
H
N
CH3CH2 N CH3 N
H
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NNoommeennccllaattuurree ooff AAmmiinneess
• Simple 1°, 2°, and 3° amines: common (trivial)
names are obtained by alphabetically arranging the
names of the alkyl substituents on the nitrogen and
adding the suffix -amine (e.g., ethylmethylamine).
• 1° amines: in the IUPAC system the -NH group in
2
primary amines is treated as a substituent, and
named as the amino group. The rest of the molecule
is named in the usual way.
• Aromatic amines: named as derivatives of the
parent compound aniline. Substituents attached to
the nitrogen are indicated by using “N-” as the
location number.
NH2
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aniline
Chapter 6 Notes
EExxaammpplleess:: NNoommeennccllaattuurree ooff AAmmiinneess
• Provide common names for the following 2° and 3°
amines; for 1° amines, provide common and/or
IUPAC names where possible.
H H
CH NH CH N CH CH N CH CH
3 2 3 3 3 2 3
NH CH
2 3
CH CH CH NH CH CH CH CHCH CH N CH
3 2 2 2 3 2 2 3 3 3
OH
CH CHCH CH NH O NH
3 2 2 2 2
NH
2
NH CH CCH CH CH CHCH
2 3 2 2 2 3
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EExxaammpplleess:: NNoommeennccllaattuurree ooff AAmmiinneess
• Provide names for the following aromatic amines.
NH CH NH2 CH3 CH3 CH3 CH2CH3
3 N N
CH
3
CH CH CH H CH CH
3 3 3 3 3
N N N
CH CH CH CH CH CH
3 2 3 3 2 3
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Chapter 6 Notes
EExxaammpplleess:: NNoommeennccllaattuurree ooff AAmmiinneess
• Draw structural formulas for the following molecules:
– ethylisopropylamine
– tert-butylamine
– 2-aminopentane
– 1,6-diaminohexane
– 2,3,6-triaminobenzoic acid
– 3-amino-1-propanol
– N-methyl-2-chloroaniline
– N,3-diethylaniline
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PPhhyyssiiccaall PPrrooppeerrttiieess ooff
AAmmiinneess
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Chapter 6 Notes
PPhhyyssiiccaall PPrrooppeerrttiieess ooff AAmmiinneess:: HH--BBoonnddiinngg
• 1° and 2° amines can hydrogen bond to each other:
CH N H CH N CH
3 3 3
H H
H H
CH N H N H CH N H N CH
3 3 3
H CH CH CH
3 3 3
• 3° amines cannot hydrogen bond to each other:
CH N CH
3 3
CH CH
3 3
X
CH N CH XN CH
3 3 3
CH CH 11
3 3
PPhhyyssiiccaall PPrrooppeerrttiieess ooff AAmmiinneess:: BBooiilliinngg PPooiinnttss
• Nitrogen is less electronegative than oxygen, so the
N—H bond is not quite as polar as the O—H bond.
– Hydrogen bonds from N—H’s are not as strong
as those resulting from O—H’s.
– Hydrogen bonding between 1° and 2° amines is
not as strong as those found in alcohols or
carboxylic acids.
• 1° and 2° amines have lower boiling points than
alcohols of similar molecular weight.
• 3° amines, since they do not hydrogen bond to each
other, have boiling points similar to hydrocarbons of
the same molecular weight.
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Chapter 6 Notes
PPhhyyssiiccaall PPrrooppeerrttiieess ooff AAmmiinneess:: BBooiilliinngg PPooiinnttss
Boiling Point:
Carboxylic acid
Alcohols
1°/2° Amines
3° Amines/Alkanes
Molecular Boiling
Name
weight point
Acetic acid 60.0 g/mol 118°C
1-propanol 60.1 g/mol 97°C
propylamine 59.1 g/mol 48°C
ethylmethylamine 59.1 g/mol 36°C
trimethylamine 59.1 g/mol 2.9°C
butane 58.1 g/mol -0.5°C
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PPhhyyssiiccaall PPrrooppeerrttiieess ooff AAmmiinneess:: WWaatteerr SSoolluubbiilliittyy
• 1°, 2°, and 3° amines can all form hydrogen bonds
with water.
• Low-molecular weight amines are generally water-
soluble.
H H H
O O O
H H H H H
CH N H O CH N H O CH N CH
3 3 3 3
H H
H CH CH
3 3
O
H H
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Chapter 6 Notes
PPhhyyssiiccaall PPrrooppeerrttiieess ooff AAmmiinneess:: OOddoorr
• Low molecular-weight amines tend to have sharp,
penetrating odors similar to ammonia
• Higher molecular-weight amines often smell like
rotting fish, and are often found in decaying animal
tissues.
NH NH
2 2
CH N CH CH CH CH CH CH CH CH CH CH
3 3 2 2 2 2 2 2 2 2 2
CH NH NH
3 2 2
Trimethylamine 1,4-Diaminobutane 1,5-Diaminopentane
Responsible for the (Putrescine) (Cadaverine)
odor of rotting fish A poisonous oil present in A poisonous, viscous liquid
rotting flesh; produced present in rotting flesh;
during the decomposition of produced during the
the amino acid arginine; also decomposition of the amino
partially responsible for the acid lysine; also partially
odorofurineandbadbreath responsible for the odor of
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urineandbad breath
EExxaammpplleess:: PPrreeddiiccttiinngg PPhhyyssiiccaall PPrrooppeerrttiieess
• Arrange the following compounds in order of
increasing boiling point. (All of the compounds
have about the same molecular weight.)
propanoic acid, diethylamine, 1-butanol,
ethyldimethylamine
• Which member of each of the following pairs of
compounds would you expect to have a higher
boiling point?
– 2-aminopropane or 2-aminohexane
– triethylamine or 1-aminohexane
– propanoic acid or diethylamine
– 1-pentanol or 1-aminopentane
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Chapter 6 Notes
SSoommee IImmppoorrttaanntt
AAllkkaallooiiddss
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IImmppoorrttaanntt AAllkkaallooiiddss
O CH3 O CH3 H
CH3 N H N
N N N
CH
O N N O N N N 3
Nicotene
CH3 CH3 Found in tobacco plants; mild
Caffeine Theobromine stimulant in small doses;
Found in the seeds of Coffea arabica, Found in the seeds of addictive, but not especially
roasted coffee beans; inhibits the action of Theobroma cacao; the harmfulitself
phosphodiesterase, an enzyme which stimulating ingredient in
inhibits cyclic adenosine monophosphate chocolate.
(AMP), which is responsible for forming
glucose in the bloodstream
CH
3 N
HO
N
CH O
3
N
Dextromethorphan Quinine
CH3OIngredient in cough suppressants. Antimalarial drug from cinchona tree 18
Chapter 6 Notes
CH CH CH
3 3 3
N O N N
OCH
3 O
H
H
O H H
O O
O
O O OH
OH
Cocaine Atropine
The form which is “snorted” relaxes muscles and reduces secretion
is the hydrochloride salt; the of saliva during surgery; used to Scopolamine
free-base “crack” form is dilate pupils for eye examinations. used in treatment of motion
burned and inhaled, and sickness
reaches the brain in 15
H C CH
seconds. 3 3
N+
R
N Zephiran chloride
H H (benzalkonium chloride)
Coniine Antiseptic compound that kills
Poisonfromhemlock bacteria and fungi on contact
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O O CH2CH3
H N
N CH CH
2 3
CH3O H
N
CH
N 3
H
H
Melatonin
A naturally occuring hormone produced in the
pineal gland; its production is triggered by the N
absence of light; causes drowsiness in humans H
Lysergic acid diethylamide (LSD)
at night, triggers birds to migrate, and signals
A synthetic hallucinogen from alkaloids obtained
dogs to shed their winter coats; sold as a
from ergot, a fungus which grows on rye
treatment for jet lag.
OH
Strychnine N
H N A poison from strychnos N
O
plant (Nux vomica); used
H H as a rat and mouse poison HO P O N N
N OH
H
OH OH
O O
H Inosine Monophosphate (IMP)
With monosodium glutamate (MSG), one of the
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major substances responsible for the flavor of meat