Question

 Explain it with reason. 

(i) tert-Butylamine cannot be prepared by the action of NH₃ on tert-butyl bromide. 

(ii) Isocyanides are hydrolysed by dilute acids but not by alkalis to form amine and formic acid. 

(iii) How will you explain the acidic nature of 1º and 2º nitroalkanes? 

(iv) Aniline does not undergo Friedel Craft’s reaction? 

(v) Although boron trifluoride adds on trimethylamine, it does not add on triphenylamine. Comment.

Answer 1

(i) Steric hinderance 

(ii) Isocyanides are stable in strong basic conditions, but they are sensitive of acids.

(iv) Aniline forms a salt with AlCl₃. Due to this nitrogen atom of aniline acquires a positive charge and hence acts as a strong deactivating group and doesn’t allow the reaction to take place. 

(v) The basicity of nitrogen in trimethylamine is greater.