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MHT CET · Chemistry · Carboxylic Acid Derivatives

Which of the following reactions involves \(\alpha\) -halogenation of carboxylic acid?

  1. A Gattermann reaction
  2. B Riemer - Tiemann reaction
  3. C Sandmeyer reaction
  4. D Hell-Vohlard-Zelinsky reaction
Verified Solution

Answer & Solution

Correct Answer

(D) Hell-Vohlard-Zelinsky reaction

Step-by-step Solution

Detailed explanation

Hell Volhard Zelinsky (HVZ) reaction:
This reaction involves alpha bromination of carboxylic acids. Carboxylic acids react with chlorine or bromine in presence of small amount of red phosphorous to give alpha halo carboxylic acids.
\(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{COOH} \stackrel{\mathrm{Br}_{2} / \mathrm{P}}{\rightarrow} \mathrm{CH}_{3}-\mathrm{CHBr}~-\) \(\mathrm{COOH} \stackrel{\mathrm{Br}_{2} / \mathrm{P}}{\rightarrow} \mathrm{CH}_{3}-\mathrm{CBr}_{2}-\)
\(\mathrm{COOH} \stackrel{\mathrm{Br}_{2} / \mathrm{P}}{\longrightarrow}\) No further reaction.