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: Understanding the Question:
We are asked to identify the specific named organic reaction that couples two chlorobenzene molecules to generate a biphenyl product.

Step 2: Key Formula or Approach:
Coupling reactions using metallic sodium in dry ether vary depending on the nature of the organic halides used: 1. Alkyl halides + Na/ether $\rightarrow$ Alkanes (

Wurtz Reaction)
2. Aryl halides + Na/ether $\rightarrow$ Biphenyls (

Fittig Reaction)
3. Alkyl halide + Aryl halide + Na/ether $\rightarrow$ Alkylbenzene (

Wurtz-Fittig Reaction)

Step 3: Detailed Explanation:
Let's evaluate the named choices to verify their chemical transformations: 4.

Swartz reaction: A halogen exchange method used to synthesize alkyl fluorides by treating alkyl chlorides/bromides with metallic fluorides like AgF or $\text{SbF}_3$.
5.

Wurtz reaction: Involves the coupling of aliphatic alkyl halides with sodium metal to yield symmetrical alkanes.
6.

Fittig reaction: Two molecules of an aryl halide (such as chlorobenzene) are treated with sodium metal in the presence of dry ether. The sodium atoms abstract the chlorine atoms, creating phenyl radicals that couple together to form a diphenyl (biphenyl) structure: $$2\text{C}_6\text{H}_5\text{Cl} + 2\text{Na} \xrightarrow{\text{Dry Ether}} \text{C}_6\text{H}_5\text{-C}_6\text{H}_5\text{ (Biphenyl)} + 2\text{NaCl}$$ 7.

Finkelstein reaction: A halogen exchange method where an alkyl chloride or bromide is converted into an alkyl iodide using sodium iodide (NaI) in acetone.

Step 4: Final Answer:
The reaction that yields biphenyl from chlorobenzene is the Fittig reaction, which corresponds to option (C).