Chapter 18 Amines and Amides

1. Chapter 18 Amines and Amides 18.2Properties of Amines

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

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

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

5. 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?

6. 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

7. Amines React as Bases Amines are • Brønsted-Lowry bases that attract a H+ from H2O to the N atom • weak bases in water

8. 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

9. Properties of Amine Salts Amine salts are • solids at room temperature • soluble in water and body fluids • the form used for drugs

10. Cocaine Cocaine • is sold illegally as an amine salt • is reacted with NaOH to produce the free amine form known as “crack”

11. Learning Check Write the equation for ethylamine when it reacts with each of the following: A. H2O B. HCl

12. Solution Write the equation for ethylamine when it reacts with each of the following: A. B.