Question

\(\text{o-Phenylenediamine}\) \(\xrightarrow{HNO_3} X\text{ Major Product X is}\): 

• A.

  

• B.

  

• C.

  

• D.

  

Hint:

When performing reactions involving amines, the functional group often reacts with the reagent to form imines or other derivatives based on the substitution pattern of the aromatic ring.

Answer 1

The Correct Option is C

To determine the major product formed when o-Phenylenediamine is treated with nitric acid \((HNO_3)\), we can analyze the nitration process on an aromatic amine compound.

o-Phenylenediamine is a benzene derivative with two adjacent amine \((NH_2)\) groups. Under nitration conditions, such as using \(HNO_3\), these amine groups can influence the position and occurrence of electrophilic substitutions due to their strong activating and ortho-/para-directing nature.

Given the strong activating nature of the \(-NH_2\) groups, the nitration will predominantly occur at the position ortho and para to these groups. However, since both amine groups are in the ortho position relative to each other, the available position that is least hindered and preferred for substitution in the electron-rich aromatic ring is between the amine groups.

Thus, the major product of the nitration of o-Phenylenediamine will occur at the remaining adjacent ortho position, resulting in the introduction of a nitro \((NO_2)\) group in between the two amine groups.

The correct transformation is:

When o-phenylenediamine is treated with nitric acid, nitration occurs at the position ortho to the amino group. The nitro group (\(NO_2\)) replaces the hydrogen attached to the benzene ring, forming a nitrated product. In this case, the major product formed is an imine (\(C = N\)) structure, which is the result of the reaction between the amino group and the nitro group.
Thus, the correct product is a structure with a carbon-nitrogen double bond (C = N).