Nucleophilic properties of amines

Question 1

How can primary amines be formed?

Answer 1

= nucleophilic subs
= one stepped reaction
= however lone pair remains on the nitrogen in the primary amine

Question 2

What can the primary amine formed from the nucleophilic subsution of a haloalkane with ammonia do?

Answer 2

= react sucessivley forming secondary amines, teritary amines, and quaternary ammonium salts

Question 3

How do we form the different groups of amines?

Answer 3

= react the priamry amine, can react further with an haloalkane, due to the lone pair of electrons on the nitrogen
= secondary amine reacts to form teritary amine- with haloalkane
=

Question 4

How do we get the quaternary ammonium salt?

Answer 4

= using an excess of haloalkane
= promote this formation
= these are not amines
= N+ charge and a halide - ions
= only first step of mechanism happens

Question 5

What are quaternary salts used as?

Answer 5

= cationic surfactants
= reduce surface tension of liquids
= positive charge of nitrogen is attracted to the negativley charged surfaces such as hair, fibres and plastics, helps uses as fabrid softeners, hair conditoning ect..

Question 6

why is reacting haloalkanes and ammonia not effificnet?

Answer 6

= not efficient for preparing a high yield of primary amines- as further subtutuon reactions can occur

Question 7

What is a beter method?

Answer 7

= 2 stepped method
= convert haloalkane into nitrile using pottasium cyanide, in aqrous ethanol heated under reflux
= reduce nitrile into amine, using LiAlH4 or by reducing using H2, using a nickel catakyst
= 4[H]

Question 8

What is the disadvantage to this method?

Answer 8

= two step reaction
= low yield
= KCN is toxic
=