1. Amines and Amides
Chapter 16

2. Nitrogen Fourth most common atom in living systems.
Important component of the structure of nucleic acids, DNA, and RNA
Essential to the structure and function of proteins – enzymes and antibodies

3. Amine Structure Characterized by the presence of an amino group (-NH2)
One or more of the hydrogen atoms can be replaced by an organic group.

4. Amines
Organic derivatives of ammonia and, like ammonia, they are basic.
Amines are classified according to the number of alkyl groups attached to the nitrogen.

5. Classification of Amines
Primary (1°) – one hydrogen replaced
Secondary (2°) – two hydrogens replaced
Tertiary (3°) – three hydrogens replaced

6. Properties of Amines
Because nitrogen is more electronegative than hydrogen, the N-H bond is polar.
Hydrogen bonding can occur between amines and water.
Primary and secondary amines have higher boiling points than tertiary amines because tertiary amines cannot form hydrogen bonds.
Small amines (six or fewer carbons) are soluble in water.

7. Naming Amines - IUPAC Least common system used
Parent chain is longest continuous chain to which the amine group is attached.
Use a number to indicate the position of the alkane.
Add the prefix “amino” to the name of the alkane.
If a substituent is present on the nitrogen, it is designated by the prefix N-alkyl.

8. Naming Amines - IUPAC aminomethane aminoethane N-methylaminomethane
N-methylaminoethane
N,N-dimethylaminomethane

9. Naming Amines – CA system
CA system – Chemical Abstracts system
The final –e of the parent name is dropped and the suffix –amine is added.
For secondary and tertiary amines, the prefix N-alkyl is added to the parent compound.

10. Naming Amines – CA system
methanamine
ethanamine
N-methylmethanamine
N-methylethanamine
N,N-dimethylmethanamine

11. Aromatic Amines Aniline or benzenamine o-toluidine p-toluidine
m-toluidine

12. Other Common Name Amines
methylamine
ethylamine
dimethylamine
ethylmethylamine
trimethylamine

13. Amides
Products formed in a reaction between a carboxylic acid and an amine.
Contains two portions: the carbonyl group from a carboxylic acid and the amino group from the amine
Amide Bond

14. Properties of Amides Most are solids at room temperature
Very high boiling points – hydrogen bonding between N-H bond of one amide and the C=O group of the second amide
Simpler ones are quite soluble in water
Unlike amines, amides are NOT bases

15. Naming Amides - IUPAC
Replace the –oic acid from the carboxylic acid with the ending –amide.
Substituents on the nitrogen are placed as prefixes and are indicated by N- followed by the name of the substituent.

16. Examples
Ethanamide
Acetamide
Propanamide
N-methylpropanamide