Question

How do you convert:
Chlorobenzene to biphenyl

Hint:

The Wurtz-Fittig reaction is used for coupling two aromatic rings to form biphenyl.

Answer 1

Chlorobenzene to Biphenyl Conversion:

The synthesis of biphenyl (C₆H₅-C₆H₅) from chlorobenzene (C₆H₅Cl) is achieved via the Wurtz-Fittig Reaction. This is a cross-coupling process where two aryl halides react with sodium metal.

Reaction:

2 C₆H₅Cl + Na → C₆H₅-C₆H₅ + 2 NaCl

Mechanism:
1. Performed in dry ether with heating, sodium metal transfers electrons to chlorobenzene, producing a phenyl radical (C₆H₅•) and sodium chloride (NaCl). 2. Two phenyl radicals combine to yield biphenyl (C₆H₅-C₆H₅).

Conditions:
- Sodium metal (Na) acts as the reducing agent.
- Anhydrous ether is essential to exclude moisture.

Summary:
Heating chlorobenzene with sodium metal in ether initiates a Wurtz-Fittig reaction, resulting in the formation of biphenyl.