General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.1 Chapter 18 Amines and Amides 18.2 Properties of Amines

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.2 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.3 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.4 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.5 Learning Check Consider the following compounds: 1) CH 3 —CH 2 —CH 2 —NH 2 2) CH 3 —CH 2 —NH—CH 3 3) CH 3 —CH 2 —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.6 Solution Consider the following compounds: 1) CH 3 —CH 2 —CH 2 —NH 2 2) CH 3 —CH 2 —NH—CH 3 3) CH 3 —CH 2 —CH 2 —CH 3 A. Which compound has the highest boiling point? 1) CH 3 —CH 2 —CH 2 —NH 2 B. Which compound(s) is(are) soluble in water? 1) CH 3 —CH 2 —CH 2 —NH 2 2) CH 3 —CH 2 —NH—CH 3

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

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.8 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 Neutralization Forms Amine Salts

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.9 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.10 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.11 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.12 Solution Write the equation for ethylamine when it reacts with each of the following: A. B.