Amines 2

Question 1

exam Q (Amines PMT 2016-2021)

6-bromohexylamine reacts with ammonia to form 1,6-diamino hexane.
Suggest the structure of a cyclic structure that can be formed as biproduct of this reaction.

Answer 1

• You have:
  Br(CH₂)₆NH₂
• The Br will react with H of NH₂ to form HBr.
• Structure closes in on itself:
• 6 carbons and N-H embedded within (leaving 7-sided shape.)

Refer to One Note Amines Q2b to see drawing of the impurity!

Question 2

exam q (Amines PMT 2016-2021)

Phenylamine can be prepared by reduction of nitrobenzene using tin and excess HCl.
Explain why an aqueous solution is obtained from this reduction even though phenylamine is insoluble.

Answer 2

• The amine produced ie. C₆H₅NH₂ will react with HCl further to produce C₆H₅NH₃⁺ and Cl⁻ ions – which will dissolve in water.