chapter 18 amines chem 2124 – general chemistry ii alfred state college professor bensley

Chapter 18Amines

CHEM 2124 – General Chemistry II

Alfred State College

Professor Bensley

Learning Objectives Identify the characteristics of Amines Name Amines Give examples of common alkaloids Draw the products of acid-base reactions of

amines Identify and name ammonium salts Discuss the importance of amine chemistry in

the pharmaceutical and illicit drug businesses.

Amines

I. Structure and Bonding

A. IntroductionB. Classification

Amines

C. Shape, Bond Angles

D. Physical Properties1. Odor, Polarity, Hydrogen Bonding, Boiling and

Melting Points

Increasing boiling pointIncreasing boiling point

CH3CH2OCH2CH3

diethyl ether

bp = 38 oC

CH3CH2CH2CH2NH2

1-butanamine

bp = 78 oC

Amines

Increasing boiling pointIncreasing boiling point

CH3CH2CH2CH2NH2

1-butanamine

bp = 78 oC

CH3CH2CH2CH2OH1-butanol

bp = 117 oC

Increasing boiling pointIncreasing boiling point

Amines

AminesII. Nomenclature

A. Primary Amines

CH3NH2

methanamine

CH3CH2CH2CH2NH2

1-butanamine

For the common name, name the alkyl groupbonded to the N atom with the suffix “-amine.”

CH3NH2 CH3CH2CH2CH2NH2Common Name:methylamine butylamine

SystematicName:

Amines B. Secondary and Tertiary Amines

1. When the substituents (alkyl groups) are identical:

2. When substituents (alkyl groups) not identical:

Example Name the following 2o amine:

CH3CHCH3

N H

CH3

N-methyl-2-propanamine

Amines

C. Aromatic Rings with N attached

•Reminder: An NH2 group is called an amino group when named as a substituent.

AminesIII. Interesting Amines (Alkaloids)

Amines

IV. Amines as Bases

Amines

base acidconjugate

acidconjugate

base

+ Cl -

Amines

• A water-insoluble amine is converted to a water-soluble ammonium salt by treatment with acid.

water-insolublewater-insoluble

Amines