Question

Which of the following reactions is used for the conversion of alkyl chloride to alkyl iodide?

• A. Fittig reaction
• B. Finkelstein reaction
• C. Swartz reaction
• D. Friedel Craft's reaction

Hint:

To avoid confusing the two halogen exchange reactions, use this mnemonic:
Finkelstein is for Iodides (F and I don't match).
Swartz is for Fluorides (S and F don't match).

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks us to identify the specific named chemical reaction responsible for converting an alkyl chloride into an alkyl iodide.

Step 2: Key Formula or Approach:
This transformation is a classic halogen exchange reaction. To synthesize an alkyl iodide, an alkyl chloride or alkyl bromide is reacted with sodium iodide (NaI) in a solvent of dry acetone.

Step 3: Detailed Explanation:
Let's review the purpose of each named reaction in the options:
(A)

Fittig reaction: Used to couple two aryl halides to form a diaryl compound using sodium metal.
(B)

Finkelstein reaction: The exact halogen exchange reaction described. The general equation is: $\text{R-Cl} + \text{NaI} \xrightarrow{\text{dry acetone}} \text{R-I} + \text{NaCl}\downarrow$. The precipitation of NaCl in dry acetone drives the reaction forward via Le Chatelier's principle.
(C)

Swartz reaction: A different halogen exchange reaction used specifically to synthesize alkyl fluorides using metallic fluorides like AgF or $\text{CoF}_2$.
(D)

Friedel Craft's reaction: An electrophilic aromatic substitution reaction used to attach alkyl or acyl groups to a benzene ring.

Step 4: Final Answer:
The conversion of alkyl chloride to alkyl iodide is achieved via the Finkelstein reaction, which matches option (B).