3.3.11 - Amines

Question 1

What is the structure of an amide?

Answer 1

R-(C=O)-NH2

Question 2

What is the structure of an N-substituted amide?

Answer 2

R-(C=O)-NH-R

Question 3

How do you form an amine from a halogenoalkane?

Answer 3

• Nucleophilic substitution
• With excess ethanolic ammonia

Question 4

What is the two step process to get from a halogenoalkane to a amine?

Answer 4

Haloalkane to nitrile via Nsub
Reduction of nitrile to a primary amine

Question 5

How do you form a nitrile from a halogenoalkane? (2)

Answer 5

• KCN
• In aqueous alcohol + reflux

Question 6

How does acyl chloride form amides?

Answer 6

Addition-elimination reaction

Question 7

What are the two steps to form aromatic amines?

Answer 7

• Reduction of nitrobenzene with tin and conc HCl under reflux

Question 8

Why might one amine be a better base than the other? (2)

Answer 8

• Lone pair may be more available
• Due to the inductive (pushing) effect of alkyl groups

Question 9

Why might one amine be a worse base than the other? (2)

Answer 9

• Lone pair may be delocalised into the benzene ring
• Less available

Question 10

Why is it better to prepare amines from nitriles than halogenoalkanes?

Answer 10

• Halogenoalkane reaction has a lower atom economy compared to the nitrile reaction

Question 11

Conditions for reducution of a nitrile into an amine

Answer 11

• LIAlH4 (reducing agent) with ether

Question 12

Catalytic hydrogenation conditions to reduce a nitrile into an amine (2)

Answer 12

• H2 gas
• Nickel catalyst

Question 13

What are the conditions for the reduction of nitrobenzene into an aromatic amine? (2)

Answer 13

• Conc HCL
• Sn (tin) catalyst

Question 14

What reaction do amines undergo with acyl chlorides?

Answer 14

(Nucleophilic) addition-elimination

Question 15

Outline the nucleophilic addition-elimination mechanism

Answer 15

• NH3 attacks carbon, C=O bond breaks
• Bond reformed, chlorine eliminated, hydrogen from NH3 removed

Question 16

How do you name N-substituted amines?

Answer 16

N - (group attached to N) (amide name)