Question

Identify the substrate 'S' in the following reaction.

• A. p-Nitrochlorobenzene
• B. o-Nitrochlorobenzene
• C. 2, 4, 6 - trichloronitrobenzene
• D. 2, 4, 6 - trinitrochlorobenzene

Hint:

Three nitro groups at the ortho and para positions make the chlorine easy to replace by OH.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
Aryl halides normally resist nucleophilic substitution. Electron withdrawing groups at ortho and para positions stabilise the intermediate and make substitution easier.

Step 2: Product analysis
The product is 2,4,6-trinitrophenol (picric acid). It is formed by replacing the halogen of S with -OH.

Step 3: Reaction condition
With one nitro group, NaOH at about 443 K is needed. With three nitro groups, warming with water alone is enough.

Step 4: Identify S
So S is an aryl chloride with nitro groups at positions 2, 4 and 6, that is 2,4,6-trinitrochlorobenzene.

Final Answer:
The substrate S is 2,4,6-trinitrochlorobenzene. \[ \boxed{\text{(D) }\text{2, 4, 6 - trinitrochlorobenzene}} \]