1. 1 19.1 Amines 19.2 Naming Amines 19.3 Physical Properties of Amines Chapter 19 Amines and Amides

2. 2 Amines are organic compounds in which one or more H in ammonia, NH 3, is replaced with alkyl or aromatic groups. H H H | || H—N—H CH 3 —N—H CH 3 —N—CH 3 ammonia Amines

3. 3 Classification of Amines Amines are classified as primary, secondary, or tertiary. In a primary (1°) amine, one carbon group is bonded to the nitrogen atom. A secondary (2°) amine has two carbon groups. A tertiary (3°) amine has three carbon groups. H CH 3 CH 3 | | | CH 3 —N—H CH 3 —N—H CH 3 —N—CH 3 1° 2° 3°

4. 4 Models of Amines The three-dimensional models show the shapes of amine molecules with one or more alkyl groups bonded to the nitrogen atom.

5. 5 Simple amines are named as alkylamines. The alkyl groups bonded to the N atom are listed in alphabetical order in front of amine. CH 3 —CH 2 —NH 2 CH 3 —NH—CH 3 Ethylamine Dimethylamine CH 3 | CH 3 —N—CH 2 —CH 3 Ethyldimethylamine Common Names of Amines

6. 6 In the IUPAC system, amines are named as alkanamines. The –e in the alkane name of the longest chain is changed to –amine. The chain is numbered to locate the amine group and substituents. NH 2 | CH 3 —CH 2 —NH 2 CH 3 —CH—CH 3 Ethanamine 2-Propanamine IUPAC Names of Amines

7. 7 Each alkyl groups bonded to the N atom is named as N-alkyl groups in front of the amine name for the longest chain. HN—CH 3 | CH 3 —CH 2 —CH 2 —NH—CH 3 CH 3 —CH—CH 2 —CH 3 N-Methyl-1-propanamine N-Methyl-2-butanamine Naming Secondary and Tertiary Amines

8. 8 Aromatic Amines  The amine of benzene is named aniline. Aniline 3-Chloroaniline N-Methylaniline

9. 9 Boiling Points of Amines, Alcohols, and Alkanes The boiling points of amines are higher than alkanes, but lower than alcohols of similar mass.

10. 10 Hydrogen Bonding for Amines The polar N-H bond provides hydrogen bonding in 1°and 2° amines, but not 3°. However, the N-H bonds in amines are not as polar as the O-H bonds in alcohols.

11. 11 Solubility in Water Amines with 1-5 carbon atoms are soluble in water. The N atom in amines forms hydrogen bonds with the polar O-H bond in water.