Download Ch 16 Amines

Ch 16
Amines
Organic and Biochemsity
Section 16.1
Introduction
• Amines
– Nitrogen found in amine group is the fourth most
common element in organic chemistry
– Known for their basicity
Section 16.2
Classification and Structure
• Primary
1⁰
R
NH2
• Secondary
R
2⁰
R
• Tertiary
NH
R
3⁰
R
N
R
• Aliphatic Amines
– All carbon groups bonded to the nitrogen are
ALKYL groups
• Aromatic Amines
– One or more groups bonded to the nitrogen are
ARYL groups
• Heterocyclic Amines
– Nitrogen is a part of the RING
Identify these
examples:
NH2
CH3
CH3
NH
N
CH3
1⁰ Aromatic Amine
Aniline
2⁰ Aromatic Amine
3⁰ Aliphatic Amine
Amphetamines
• 3 examples
Amphetamine
Methamphetamine
Phentermine
• Common physiological effect:
– Reduce fatigue and diminish hunger by raising
glucose levels
• Prescribed to:
– Counter mild depression
– Reduce hyperactivity in children
– Suppress appetites
NH2
Amphetamine
CH3
CH3
NH
Methamphetamine
CH3
NH2
CH3
H3C
Phentermine
found in “Fen-Phen”
• Illegally used to:
– Reduce Fatigue
– Elevate moods – mood enhancement
• ADDICITIVE: Concentrated in Brain and CNS
leads to sleeplessness, weight loss, & paranoia
• Why? How does it work?
– Action similar to Epinepherine
– Excreted by adrenal gland
– Makes glucose more available
– Immediate glucose action
– Commonly called “Adrenalin”
HO
HO
OH
NH
CH3
Heterocyclic Amines
• Heterocyclic Aliphatic Amines
pyrrolidine
piperidine
N
H
N
H
• Heterocyclic Aromatic Amines
pyrrol
pyridine
N
H
N
1. How many hydrogens does piperidine have?
– 11
C5H11N
2. How many hydrogens does pyridine have?
– 5
C5H5N
3. Write the molecular formula of each.
4. How many hydrogens does pyrrolidene have?
– 9
C4H9N
5. How many hydrogens does pyrole have?
– 5
C4H5N
6. Write the molecular formula of each.
Alkaloids
• Naturally occurring amine compounds
– Found in roots, bark or fruits
– Nitrogen found in ring
– “Alkaloid” because compounds are BASIC
• Coniine
– Water Hemlock
– Causes weakness, labored respiration, paralysis and death
• Nicotine
– Tobacco plant
– Addictive in small doses
– Large doses cause depression, nausea, vomiting
• Cocaine
– Leaves of Coca plant
– CNS stimulant
H
H
N
N
H
CH3
N
(s) Coniine
CH3
(s) Nicotine
H
H
H
H
H
H
O
H
H
H
H
O
O
N
H
H
H
O
H
H
H
H
H
H
H
H
Cocaine
Section 16.3
Nomenclature
• Same naming system as ALCOHOLS
• Drop the “ending” or “e” of the parent chain
and add “amine”
H3C
NH2
H3C
NH2
NH2
CH3
H2N
1,6-hexandiamine
2-propanamine
1-phenyl-1-ethanamine
Write the name or formula
1. CH3(CH2)5NH2
1-hexanamine
H3C
2. 1-phenyl-2-propanamine
NH2
3. Cyclohexanamine
NH2
4. 1,4-butandiamine
NH2
H2N
• IUPAC nomenclature retains the common
name:
NH2
NH2
Aniline
H3C
CH3
• __Toluidine___ is methyl substituted aniline
– 2-methyl aniline = o-toluidine
• Largest group bonded to nitrogen is the
parent amine when nitrogen has 2 or more
carbon groups bonded to it (IUPAC)
• Groups attached to Nitrogen are numbered as “N”
NH2
CH3
• N-methylaniline
HN
H3C
• N,N-dimethyl cyclopentanamine
N
CH3
• N-ethyl-2-propanamine
H3C
CH3
HN
• N-ethyl-N-methyl ethanamine
CH3
CH3
N
H3C
CH3
Common Names
• Common names for aliphatic amines list the
groups bonded to the nitrogen in alphabetical
CH
order.
H 3C
3
H3C
H3C
NH2
Methylamine
C
CH2
NH2
N
H 2C
CH3
tert-butylamine
• Draw the structure of
Cyclohexylmethylamine
Isopropylamine
Triethylamine
CH3
CH3
diethylmethylamine
Amine Salts
• When 4 atoms or groups are bonded to the
nitrogen
• Named as a salt with an “anion” (chloride)
• Ending “amine” is replaced with -ammonium_
• Ending “aniline” is replaced with -anilinium
• Ending “pyridine” is replaced with -pyridinium
• Ammonium chloride
H
H
Cl
+
N
-
H
H
• Tetramethyl ammonium chloride H C
3
CH3
+
N
CH3
• Pyridinum chloride
• Anilinium chloride
+
H
+
Cl
N
H
H
Cl
N
H
-
-
Cl
CH3
-
Section 16.4
Physical Properties
• Amines are ___POLAR__ molecules
• Primary and Secondary amines will form
____H-Bonds___ between themselves
• Tertiary amines will NOT form __H-Bonds____
between themselves
• ALL amines will form _____H-Bonds___ with
WATER!
• The N-H h-bond is WEAKER than the O-H hbond.
• Methanamine vs. Methanol
CH3NH2
CH3OH
Molar Mass
31.1
32.0
Boiling Point
-6.3⁰C
65.0⁰C
• Why?
•Stronger H-Bonding between Methanol
Molecules
Section 16.5
Basicity
• Amines are _Slightly Strong to Weak Bases__
• Example:
H
H3C
N
H
+
H
O
H
+
H3C N
H
H
H
• Base dissociation constants


[CH 3 NH 3 ][OH ]
4
Kb 
 4.37 x10
[CH 3 NH 2 ]
+
-
HO
• 2 ways to measure “base” strength
– pKb -Log of Kb
• Smaller values = Stronger Bases
<3 = Very Strong base
>6 = Weak Base
– pH
• Larger values = Stronger Bases
13-14 = Very Strong base
8-10 = Weak Base
Amine
pKB
Base Nature
Aliphatic
3.0-4.0
Slightly Strong
Ammonia
4.74
Aromatic
8.5-9.5
Weak
For each Set, choose which is the more “basic”
NH2
NH2
CH3
N
N
H
NH2
H3C
NH3
• Basicity and Blood
– Most Aliphatic amines are fairly strong bases
– How will they be found in the blood stream?
• In their “Ionic” or “Ammonium” Form
• Example: Dopamine
HO
HO
NH2
HO
HO
H+
NH
H
HO
Section 16.6 REACTIONS
• Amines react with strong acids to form watersoluble salts
HO
HO
H
NH2
+
HO
HO
H
H
H
+
N
H
H Cl
+
HO
(R) Norepinephrine
Only Slightly water soluble
(R) Norepinephrine hydrochloride
Very water soluble
Cl
-
Solubility of amine type DRUGS
• Many drugs have “∙HCl” in their chemical formula
• WHY?
– High molecular weight amines are insoluble in blood
– Treated with an acid – they form a water/blood
soluble salt
– Amines are also susceptible to oxidation from
atmospheric O2.
– Amine salts are less likely to be oxidized and retain a
longer shelf life
– LOOK AT LABELS!
• Examples
– Phenylephrine∙HCl
H
H
HO
N
HO
CH3 HCl
• Is it (R) or (S)?
– (Neo-Synephrine)
– Procaine∙HCl
– (Novocain)
CH3
O
N
O
CH3 HCl
H2N
O
CH3
– Methadone ∙HCl
– (Methadone)
N
CH3
HO
– Albuterol ∙HCl
– (Proventil)
CH3 HCl
CH3
H
N
CH3
HO
CH3 HCl
CH3
HO
Chapter 17: Aldehydes & Ketones
Naming Introduction
Aldehydes
• Terminal –CHO group
• Suffix: “al”
• Naming similar to alcohols
O
H3C
CH3
C
C
H3C
Ketones
• Internal –C=O group
• Suffix: “one”
• Naming similar to alcohols
H
O
Name the Following
CH3
O
O
H3C
CH3
CH3
CH3
H3C
H
H3C
CH3
O
CH3
Cl
O
Draw the Following
• 1,6-dichloro-3-hexanone
• 5-methylheptanal
• 1,6-hexandial
• 3-bromo-2-butanone
Sections 17.1-17.3
• Order of Precedence of Main Functional Groups
Class
Group
Suffix if highest
Prefix if Lower
Carboxylic acid
Highest
-COOH
-oic acid
Never Lower!
Aldehyde
-CHO
-al
oxo
Ketone
-C=O
-one
oxo
Alcohol
-OH
-ol
hydroxy
Amine
-NH2
-amine
amino
• Examples: Draw the following
– 2-aminohexanal
– 1-amino-2-hydroxyl-3-pentanone
– 5-hydroxyl-2-hexenal
– 3-methyl-2-oxobutanal
– 4-amino-3-penten-2-one
• Name the following
H3C
O
O
CH2
H3C
CH3
OH
O
OH
O
CH3
O
OH
NH2