3.3.11 - Amines Flashcards
What is the structure of an amide?
R-(C=O)-NH2
What is the structure of an N-substituted amide?
R-(C=O)-NH-R
How do you form an amine from a halogenoalkane?
- Nucleophilic substitution
- With excess ethanolic ammonia
What is the two step process to get from a halogenoalkane to a amine?
Haloalkane to nitrile via Nsub
Reduction of nitrile to a primary amine
How do you form a nitrile from a halogenoalkane? (2)
- KCN
- In aqueous alcohol + reflux
How does acyl chloride form amides?
Addition-elimination reaction
What are the two steps to form aromatic amines?
- Reduction of nitrobenzene with tin and conc HCl under reflux
Why might one amine be a better base than the other? (2)
- Lone pair may be more available
- Due to the inductive (pushing) effect of alkyl groups
Why might one amine be a worse base than the other? (2)
- Lone pair may be delocalised into the benzene ring
- Less available
Why is it better to prepare amines from nitriles than halogenoalkanes?
- Halogenoalkane reaction has a lower atom economy compared to the nitrile reaction
Conditions for reducution of a nitrile into an amine
- LIAlH4 (reducing agent) with ether
Catalytic hydrogenation conditions to reduce a nitrile into an amine (2)
- H2 gas
- Nickel catalyst
What are the conditions for the reduction of nitrobenzene into an aromatic amine? (2)
- Conc HCL
- Sn (tin) catalyst
What reaction do amines undergo with acyl chlorides?
(Nucleophilic) addition-elimination
Outline the nucleophilic addition-elimination mechanism
- NH3 attacks carbon, C=O bond breaks
- Bond reformed, chlorine eliminated, hydrogen from NH3 removed
