3.11 Amines

Question 1

What are the properties of Amines?

Answer 1

• Soluble in water due to formation of H bonds
• Nucleophilic due to lone pair on N
• Weak bases so proton acceptor

Question 2

What is the order of basicity?

Answer 2

Weakest :Aromatic Amines, Ammonia, Primary,secondary,Tertiary: Strongest

Question 3

Why are aromatic amines the weakest bases?

Answer 3

Lone pair of e- is delocalised and pulled into pi ring so less available to accept H+

Question 4

Why are Tertiary amines the strongest?

Answer 4

NH directly bonded to 3 alkyl groups
Pushes e-density onto N
Lone pair of electrons more available to accept H+

Question 5

What are the conditions required for reacting Haloalkanes with Amines?

Answer 5

XS NH3
Under pressure to avoid further substitution

Question 6

What are the advantages and disadvantages of reacting amines with haloalkanes?

Answer 6

• 1 Step
  Disadvantages:
  Mix of products
  Gases under pressure are expensive

Question 7

What are the conditions required for reaction of Halo =alkane + CN- to form nitrile?

Answer 7

Acidified HCN
LiALH4 and ether catalyst

Question 8

What are the advantages and disadvantages of reacting haloalkanes with CN- to form an amine?

Answer 8

Advantages:
- No further sub
- 2nd step is 100% atom economy

Disadvantages:
- Two step process
- CN- is toxic