Question

The reduction of which of the following compounds would yield secondary amine?
A. Alkyl nitrile
B. Carbylamine
C. Primary amine
D. Secondary nitro compounds

Answer 1

Hint: Reduction is the addition of hydrogen or removal of oxygen from the compounds. In secondary amine, two alkyl groups of any hybridization are attached to the nitrogen of the amine group.

Complete Step by Step Solution:
In the first option, alkyl nitrile gives primary amines on reduction. In option C, primary amine will not reduce at all as it is a reduced product of amide. In option D, secondary nitro compounds reduce to give primary amine. Carbylamine, also called isocyanide, gives secondary amine on reduction. Carbylamine is a primary amine. It has an isocyanate functional group in which one pie bond breaks and hydrogen gets attached to the nitrogen and carbon atom of the isocyanide group to give an amine functional group where nitrogen is attached to two carbons. Reduction of carbylamine can be done in presence of hydrogen gas and any metal like nickel or platinum and this takes place as follows:


Image:Reduction of carbylamine

So, option B is correct.

Note: Secondary nitro compounds are those which have two carbons attached to the carbon which is adjacent to the nitrogen of the nitro functional group. On reduction, the oxygen of nitro groups gets removed and two hydrogens get attached to the Nitrogen of the nitro functional group. So, the product will have only one carbon attached to the nitrogen of the amine group which is a primary amine.