Download Chapter Fifteen

15.1 Amines
Amine: A compound that has one or more organic
groups bonded to nitrogen: primary, RNH2,
secondary, R2NH, or tertiary, R3N.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
1
Primary alkyl amines are named by identifying the
alkyl group attached to nitrogen and adding the
suffix -amine to the alkyl group name.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
2
Simple, secondary and tertiary amines (those possessing two
or three identical groups on the nitrogen, respectively) are
named by adding the appropriate prefix, di- or tri-, to the
alkyl group name along with the suffix -amine.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
3
► When R groups in 2 or 3 amines are different, the
compounds are named as N-substituted derivatives
of a 1 amine. The parent compound is chosen as the
1 amine that contains the largest of the R groups.
► All other groups are considered to be N-substituents.
The following compounds are named as
propylamines because the propyl group in each is the
largest alkyl group:
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
4
► The simplest aromatic amine is known by the
common name aniline.
► The –NH2 functional group is an amino group, and
when this group is a substituent, amino- is used as a
prefix.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
5
15.2 Properties of Amines
The lone electron pair on the N in amines causes
amines to be weak Brønsted–Lowry bases or Lewis
bases, electron pair donors, by forming a bond with
an H+ ion from an acid or water.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
6
► Protein in flesh contains amine groups. Volatile amines
produced during decay are responsible for the odor of rotten fish
or decaying meat. Cadaver-sniffing dogs are used to detect the
strong odor of the amines produced from decaying flesh.
► Many amines cause
physiological responses.
Simpler amines are
irritating and toxic.
Some complex amines
from plants can be very
poisonous. Many useful
drugs are amines.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
7
► Because of hydrogen bonding, 1 and 2 amines have
higher boiling points than alkanes of similar size.
Amines are lower boiling than alcohols of similar size.
► All amines can hydrogen-bond to water molecules
through the lone electron pair on their nitrogen atoms.
Amines with up to about 6 C’s are soluble in water.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
8
3 amine molecules have no H atoms attached to N and therefore
cannot hydrogen-bond with each other. As a result they are much
lower boiling than alcohols or 1 or 2 amines of similar
molecular weight.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
9
15.3 Heterocyclic Nitrogen Compounds
► Heterocycle: A ring that contains nitrogen or some
other atom in addition to carbon.
► Heterocycles are common in many natural
compounds found in plants and animals.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
10
15.4 Basicity of Amines
► Aqueous solutions of amines are basic because of the
formation of Ammonium ions. Positive ions formed
by addition of H+ to ammonia or an amine.
► Nonaromatic amines are slightly stronger bases than
ammonia, which is stronger than aromatic amines.
► Amines exist as ammonium ions in the aqueous
environment of blood and other body fluids.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
11
15.5 Amine Salts
► Ammonium salt: An ionic compound composed of
an ammonium cation and an anion; an amine salt.
► Ammonium salts are generally odorless, white,
crystalline solids that are much more water-soluble
than neutral amines because they are ionic.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
12
► Diphenhydramine is available in over-the-counter
medications. Antihistamines of this type are oily
liquids and difficult to formulate as such, so they are
converted to amine salts for formulation into
medications. Diphenhydrammonium chloride is also
called Diphenhydramine hydrochloride.
► In medicinal chemistry,
amine salts are named by
combining the names of
the amine and the acid
used to form its salt.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
13
15.6 Amines in Plants: Alkaloids
Alkaloid: A naturally occurring, nitrogen-containing
compound isolated from a plant; usually basic, bitter,
and poisonous. The bitterness and poisonous nature
of alkaloids probably evolved to protect plants from
being devoured by animals.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
14
► Many alkaloids are physiologically active.
► Caffeine and nicotine are stimulants.
► Others are notable as pain relievers (analgesics), as
sleep inducers, and for the euphoric states they can
create.
Copyright © 2010 Pearson Education, Inc.
Chapter Fifteen
15