Bioorganic Chemistry

AminesChapte 16

Amines

Amine Nomenclature– Amines are derivatives of Ammonia, NH3

– Classified as 1o, 2o, and 3o amines

N H

H

R

a primary amine

N R'

H

R

a secondary amine

N R'

R''

R

a tertiary amine

(Count R groups on Nitrogen.)

IUPAC Nomenclature

Amines are named by naming the “R” groups

And adding “amine” as a suffix

t-butylamine

H2N C

CH3

CH3

CH3

methylethylamine

NH CH2 CH3CH3

isopropylamine

H2N CH

CH3

CH3triethylamine

N CH2 CH3CH2CH3

CH2

CH3

Nomenclature Aromatic amines

– Aniline is parent– Substitution on N is named as a

“N-alkyl” or “N,N-dialkyl” aniline

N-methylaniline

HN CH3

NH2

aniline

meta-bromo-N,N-diethylaniline

N CH2 CH3CH2CH3

Br

3

Nomenclature

Nomenclature– Use a “N” to locate alkyl groups– More complicated amines are use “amino” to

name the N group as a substituent

o-chloro-N-propylaniline

HN CH2CH2CH3

Cl

3-aminobutanoic acid

CCH2CHCH3 OH

ONH2

p-aminobenzoic acid

COOH

NH22

Nomenclature

Heterocyclic Amines

Pyridine

N

Piperidine

NH

Pyrimidine

N

N

Pyrrole

NH

Pyrrolidine

NH

* *

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A Little Organic Fun

http://www.youtube.com/watch?v=mAjrnZ-znkY

http://www.youtube.com/watch?v=HPGE_GJkLJA

Physical Properties

Amine Physical Properties

– Boiling points slightly

lower than alcohols

– Hydrogen bonding

» occurs with 1o and 2o amines

» not possible with 3o amines

– Water solubility is similar to same MW

alcohols

methylethylamine

N CH2 CH3CH3

H

Physical Properties Amine Physical Properties

– Strong odors» simple amine have an odor similar to ammonia

» resemble the odor of raw fish

» some diamines have especially bad odors

(1,4-diaminobutane)

CH2CH2CH2H2C

NH2NH2

Putrescine Cadaverine(1,5-diaminopentane)

CH2CH2CH2CH2H2CNH2NH2

Pyridine

N

P y r i d i n e

N

Reaction of Amines Amines are BASES!

– React with acids and accept a proton (H+) to Form alkyl ammonium salts

methylamine

NH2H3C + HCl

methylammonium chlorideNH3

+ Cl-H3C

diethylamine

NH CH2 CH3CH2CH3 + HCl

diethylammonium chloride

NH2CH2 CH3CH2CH3+

Cl-

N,N-dimethylaniline

N CH3CH3

+ HCl

NH CH3CH3

N,N-dimethylanilinium chloride

+Cl-

Reaction of Amines

Amines are BASES!

diethylamine

NH CH2 CH3CH2CH3 + CH3COOH

acetic acid

diethylammonium acetateNH2 CH2 CH3CH2CH3

+CH3COO-

?

Reaction of Amines

Amines are BASES!

diethylamine

NH CH2 CH3CH2CH3 + CH3COOH

acetic acid

diethylammonium acetateNH2 CH2 CH3CH2CH3

+CH3COO-

Nomenclature

Nomenclature

methylamine

NH2H3C + HCl

methylammonium chlorideNH3

+ Cl-H3C

Quaternary Ammonium Salts

Four alkyl groups on N– only with ammonium salts– NOT made by acidifying an amine

diethyldimethylammonium bromide

NCH3

CH3CH2 CH3CH2H3C

+Br

-

So……. Tell me about some Way Cool far out Amines…………..

From Yahoo Images

Alkaloids Nitrogen containing compounds found in

roots, bark, leaves, berries, or fruit. Thousands have been extracted (in

containers or by chewing) and used to produce physiological effects in humans and animals

Some are deadly poisons, some cure diseases and some are addictive drugs

atropine

C CH

O

N

H

O

CH2OH

CH3

Alkaloid Example

Coniine– Simple alkaloid– Very poisonous– Hemlock plant

» Socrates (469-399 BC) coniine

NH

CH2CH2CH3

Hemlock From Yahoo Images

Socrates (469-399 BC) was found guilty of corrupting the minds of the youth of Athens and sentenced to death by drinking a mixture containing poison hemlock.

Alkaloid Example

Nicotine– Found in smoking, chewing– Stimulant in small doses– Habit forming– Tars, CO, carcinogens

present in smoke

N

N

CH3

nicotine

From Yahoo Images

How do you know how muchNicotine is in a smoke?

Alkaloid Example

Caffeine– Stimulating action– Found in:

» coffee» tea (black, green)

» colas

» No-Doz» chocolate (theobromine)

caffeine

N

CN

C N

NO

O

H3C

CH3

CH3

From Yahoo Images

Alkaloid Example Atropine

– Plants:» henbane

» Belladonna- (deadly nightshade)

– Dilate pupils of eyes» “used by Cleopatra and

Roman Women to

Enlarge the pupils to

Look more attractiveatropine

C CH

O

N

H

O

CH2OH

CH3

From Yahoo Images

Alkaloid Example Morphine

– Found in Opium Poppy– Simular compounds include

Codeine, Heroin, Demerol, Methadone– Valuable pain killer– Troubled drug for abuse

morphine

N

HO

O

HO

CH3

From Yahoo Images

Other Alkaloid Example

Quinine– Cinchona bark– Used to treat

Malaria Strychnine

– Nux Vomica– rat poison

Reserpine– Indian Snake Root– lowers bp

N

CH3O

HC

OH N

CH=CH2

quinine

Indian Snake Root from Yahoo Images

Amphetamines Amphetamines

– Synthetic amines– Powerful stimulants CNS

» reduce fatigue

» raise glucose blood level

» control mild depression

» reduce hyperactivity in children

» appetite depressant

CH2 CH CH3

NH2

amphetamine (benzedrine)