Consider the following reaction: Name of the reaction is :

The correct answer is Option (4) → Fittig reaction

Sodium in dry ether joins two organic groups of halides by removing the halogen as NaX. The three coupling reactions differ in what is coupled:

• Wurtz reaction: two alkyl halides give an alkane (R–R).

• Wurtz-Fittig reaction: an alkyl halide and an aryl halide give an alkylarene (Ar–R).

• Fittig reaction: two aryl halides give a diaryl (Ar–Ar).

Here only an aryl halide is used and two aryl groups join, so it is the Fittig reaction. Chlorobenzene gives biphenyl:

    \( \ce{2C6H5Cl + 2Na} \xrightarrow{\text{dry ether}} \ce{C6H5-C6H5 + 2NaCl} \)

• Option (1) Balz-Schiemann reaction — Incorrect. It prepares aryl fluorides: the diazonium fluoroborate is heated and decomposes. No sodium and no coupling are involved.

      \( \ce{ArN2^+BF4^-} \xrightarrow{\Delta} \ce{Ar-F + BF3 + N2} \)

• Option (2) Wurtz reaction — Incorrect. Two alkyl halides are joined by sodium in dry ether to give an alkane.

      \( \ce{2R-X + 2Na} \xrightarrow{\text{dry ether}} \ce{R-R + 2NaX} \)

• Option (3) Wurtz-Fittig reaction — Incorrect. A mixture of an alkyl halide and an aryl halide gives an alkylarene; here only the aryl halide is used.

      \( \ce{Ar-X + R-X + 2Na} \xrightarrow{\text{dry ether}} \ce{Ar-R + 2NaX} \)

• Option (4) Fittig reaction — Correct. Two aryl halides are coupled by sodium in dry ether to give a diaryl, as in the reaction shown.

NCERT (2026-27 edition):
Reaction with Metals