Question

Choose the correct order of the basic nature of the below-given amines.

A. Phenyl methenamine

B.$\mathrm{N}-\mathrm{N}$-Dimethylaniline

C. $\mathrm{N}$-Methyl aniline

D. Benzenamine

• A. $\mathrm{D}>\mathrm{C}>\mathrm{B}>\mathrm{A}$
• B. $\mathrm{D}>\mathrm{B}>\mathrm{C}>\mathrm{A}$
• C. $\mathrm{A}>\mathrm{C}>\mathrm{B}>\mathrm{D}$
• D. $\mathrm{A}>\mathrm{B}>\mathrm{C}>\mathrm{D}$

Answer 1

The correct option is D

$\mathrm{A}>\mathrm{B}>\mathrm{C}>\mathrm{D}$

Explanation for the correct option:

(D)

1. The basicity is described as the proton acceptance from the acid or the donation of lone pair to Lewis acid.
2. In the phenyl methenamine the lone pair on nitrogen atom is not conjugation with the phenyl ring which means that the lone pair is localized and can be available for donation to Lewis acid.
3. However for the rest of the structure, nitrogen lone pair is delocalized and not available for donation to Lewis acid.
4. When the hydrogen atom of the amino group of aryl amine is replaced by electron-donating alkyl groups, the basic character of the resulting amine increases.
5. The above points can be summarized in below diagram:

Therefore, option (D) is incorrect.