Chapter 18 Amines and Amides 18 2 Properties

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Chapter 18 Amines and Amides 18. 2 Properties of Amines General, Organic, and Biological

Chapter 18 Amines and Amides 18. 2 Properties of Amines General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 1

Boiling Points of Amines, Alcohols, and Alkanes The boiling points of amines are §

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°

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

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) CH 3—CH 2—NH 2 2) CH 3—CH

Learning Check Consider the following compounds: 1) CH 3—CH 2—NH 2 2) CH 3—CH 2—NH—CH 3 3) CH 3—CH 2—CH 3 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. 5

Solution Consider the following compounds: 1) CH 3—CH 2—NH 2 2) CH 3—CH 2—NH—CH

Solution Consider the following compounds: 1) CH 3—CH 2—NH 2 2) CH 3—CH 2—NH—CH 3 3) CH 3—CH 2—CH 3 A. Which compound has the highest boiling point? 1) CH 3—CH 2—NH 2 B. Which compound(s) is(are) soluble in water? 1) CH 3—CH 2—NH 2 2) CH 3—CH 2—NH—CH 3 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

Amines React as Bases Amines are § Brønsted-Lowry bases that attract a H+ from H 2 O to the N atom § weak bases in water General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 7

Neutralization Forms Amine Salts An amine salt § forms when an amine is neutralized

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. 8

Properties of Amine Salts Amine salts are § solids at room temperature § soluble

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. 9

Cocaine § is sold illegally as an amine salt § is reacted with Na.

Cocaine § is sold illegally as an amine salt § is reacted with Na. OH 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

Learning Check Write the equation for ethylamine when it reacts with each of the following: A. H 2 O 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:

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. 12