Ch 13 Carboxylic Acids, Esters, Amines and Amides

SWBAT:Name/Draw compounds with functional groupsDescribe/Explain properties of functional groupsComplete/Show reactions of functional groups

Chapter 13.4Amines

Amines

• They are derivatives of ammonia NH3

• H-groups are replaced by alkyl or aromatic groups

Subclasses of Amines

Naming Amines• Similar to ether…• List the alkyl groups in alpha order• No gaps• Ends in -amine

methylamine dimethylamine

Practice

ethylmethylpropylamine

ethyldimethylamine

triphenylamine

Aromatic Amines

• Aromatic amines use the name aniline• Amino bearing Carbon is C#1

2,6-diethyl-4-methylaniline

aniline

Naming Anilines

N-ethylaniline

• Alkyl groups attached to the nitrogen of the aniline are named with the prefix N- followed by the alkyl name

N, N-dimethylaniline

Properties of Amines

Boiling Point• Amines can have polar N-H bond, so they can

form H-bonds• But…N is not as electronegative as the O in

alcohols…so the H-bonds are weaker!• BP is below AlcoholBp differences among different types of amines!• 1o amines highest BP (2 H-bonds) • 2o amine lower (1 H-bond)• 3o amine lowest (only dipole)

Properties of AminesSolubility• Amine group is polar: soluble in water, will

form H-bonds• Small amines (1-5 C atoms) are soluble• Large amines (<6 C atoms) are not

Famous Amines

• Acetyl choline – neurotransmitter

• Nicotine

Famous Amines• Prozac – Fluoxetine

• Caffeine

Reaction of Amines

A. 1o and 2o Amines react as Bases – they accept H+ ions like ammonia below:The unpaired valence e- of N attract H+

H+ H-N-H + H2O → H-N-H + OH-

H H

NH3 + H2O → NH4+ + OH-

ammonia ammonium ion

Reacting as a Base

• Primary

• Secondary

• Tertiary amines do not react!dimethyammonium ionDimethylamine

Neutralization Reaction

Base + Acid → Salt NH3 + HCl → NH4

+Cl- Ammonia Ammonium

chloride (salt)

a) Primary amineCH3-NH2 + HCl → CH3-NH3

+Cl- Methylamine methylammonium

chloride

b) Similar for secondary amine

HomeworkChapter 13

Page 448 13.34 – 13.44 (even)