Download Carboxylic Acids Esters, Amines and Amides

Chapter 18 Amines and Amides
18.2
Properties of Amines
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
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Boiling Points of Amines,
Alcohols, and Alkanes
The boiling points of amines are
 higher than alkanes of similar mass
 lower than alcohols of similar mass
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
2
Hydrogen Bonding in Amines
The polar N—H bond
 provides hydrogen bonding in 1° and 2° amines but
not 3° amines
 is not as polar as the —OH in alcohols
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
3
Solubility in Water
Amines are soluble in water
 if they have 1 to 5 carbon
atoms
 because the N atom in
smaller amines forms
hydrogen bonds with the
polar O—H bond in water
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
4
Learning Check
Consider the following compounds:
1) CH3—CH2—CH2—NH2
2) CH3—CH2—NH—CH3
3) CH3—CH2—CH2—CH3
A. Which compound has the highest boiling point?
B. Which compound(s) is (are) soluble in water?
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
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Solution
Consider the following compounds:
1) CH3—CH2—CH2—NH2
2) CH3—CH2—NH—CH3
3) CH3—CH2—CH2—CH3
A. Which compound has the highest boiling point?
1) CH3—CH2—CH2—NH2
B. Which compound(s) is(are) soluble in water?
1) CH3—CH2—CH2—NH2
2) CH3—CH2—NH—CH3
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
6
Amines React as Bases
Amines are
 Brønsted-Lowry bases that attract a H+ from H2O
to the N atom
 weak bases in water
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
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Neutralization Forms Amine Salts
An amine salt
 forms when an amine is neutralized
by an acid
 is named by replacing the amine
part of the name with ammonium
followed by the name of the
negative ion
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
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Properties of Amine Salts
Amine salts are
 solids at room temperature
 soluble in water and body fluids
 the form used for drugs
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
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Cocaine
Cocaine
 is sold illegally as an amine salt
 is reacted with NaOH to produce the free amine form
known as “crack”
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
10
Learning Check
Write the equation for ethylamine when it reacts with
each of the following:
A. H2O
B. HCl
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
11
Solution
Write the equation for ethylamine when it reacts with
each of the following:
A.
B.
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
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