Question

Identify correct A, B and C in the reaction sequence given below : 
 

• A. A
• B. B
• C. C
• D. D

Hint:

To determine the position of the second substituent, identify the nature of the first:
- \(OH, NH_2, R, X\) are ortho/para directing.
- \(NO_2, CHO, COOH, CN\) are meta directing.
Here, the meta-directing \(NO_2\) ensures that Cl ends up at the 3-position.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
This is a three-step sequence involving nitration, chlorination, and reduction. The key is understanding the directing effects of substituents on the benzene ring.
Step 2: Detailed Explanation:
1. Step 1 (\(conc. HNO_3 / conc. H_2SO_4, \Delta\)): Benzene undergoes nitration to form Nitrobenzene (\(A\)).
2. Step 2 (\(Cl_2 / \text{Anhyd. } AlCl_3\)): Nitrobenzene is chlorinated. The nitro group (\(-NO_2\)) is a strongly deactivating group and is **meta-directing**. Therefore, the chlorine atom attaches to the meta position relative to the nitro group, yielding m-chloronitrobenzene (\(B\)).
3. Step 2 (\(Fe / HCl\)): This reagent reduces the nitro group (\(-NO_2\)) to an amino group (\(-NH_2\)). It does not affect the aryl chloride. The final product is m-chloroaniline (\(C\)).
Step 3: Final Answer:
A = nitrobenzene, B = m-chloronitrobenzene, and C = m-chloroaniline. This matches option (A).