Question

Which of following reactions yields biphenyl from chlorobenzene?

• A. Swartz reaction
• B. Wurtz reaction
• C. Fittig reaction
• D. Finkelstein reaction

Hint:

To remember the distinction easily, use this mental map: Wurtz is for Water-like chains (aliphatic alkanes), Fittig is for Flat rings (aromatic biphenyls), and the combined Wurtz-Fittig couples one of each!

Answer 1

The Correct Option is C

Step 1: Understand the target reaction.
Two chlorobenzene (aryl halide) molecules must couple to give biphenyl. We need the name of this coupling.
Step 2: Recall the coupling family.
Coupling with sodium in dry ether splits by substrate: alkyl halides give the Wurtz reaction, aryl halides give the Fittig reaction, and a mix of the two gives Wurtz-Fittig.
Step 3: Test Swartz.
The Swartz reaction makes alkyl fluorides by halogen exchange - not a coupling.
Step 4: Test Wurtz.
Wurtz couples alkyl halides into alkanes, not aryl halides.
Step 5: Test Fittig.
Fittig couples two aryl halides with Na in dry ether: $2\text{C}_6\text{H}_5\text{Cl} + 2\text{Na} \rightarrow \text{C}_6\text{H}_5\text{-C}_6\text{H}_5 + 2\text{NaCl}$, exactly giving biphenyl.
Step 6: Test Finkelstein and conclude.
Finkelstein only swaps a halide for iodide using NaI in acetone. So the biphenyl-forming reaction is the Fittig reaction, option (3).
\[ \boxed{\text{Fittig reaction gives biphenyl}} \]