Question

How is a nitroalkane converted to a primary amine?

OR 

What is the action of LiAlH₄/ether on :

(i) 1- Nitropropane 

(ii) 2-MethyI-l-nitropropane?

Answer 1

When a nitroalkane is refluxed with tin (or iron) and concentrated HCl it gives corresponding primary amine.

For example,

(1) nitromethane on reduction by refluxing with Sn and concentrated HCl gives methylamine.

(2) 1-Nitropropane on reduction with Sn and concentrated HCl gives propan-1-amine.

(3) Niirobenzcnc on reducion with tin and concentrated HCI or by using H₂/Pd in ethanol gives anilinc.

(4) When nitropropane is reduced in the presence of LiAlH₄ in ether, n-propyl amine is obtained.

(5) When 2-methyl-1-nitropropane is reduced in the presence of LiAlH₄ in ether, 2-methyl propan-1-amine is obtained.