Question

Which of the following reagents is used in the Hoffmann elimination reaction of amines?

• A. NaNO\(_2\) + HCl
• B. CH\(_3\)COCl
• C. Ag\(_2\)O/H\(_2\)O, \(\Delta\)
• D. CHCl\(_3\) + KOH

Hint:

In the Hoffmann elimination reaction, silver oxide (Ag\(_2\)O) and water, under heat, facilitate the formation of an alkene from an amine by elimination of a halogen.

Answer 1

The Correct Option is C

Step 1: Understanding the Hoffmann elimination reaction.
The Hoffmann elimination reaction involves the dehydrohalogenation of amines to form alkenes, and it typically requires reagents like Ag\(_2\)O and heat to proceed effectively. The reaction is characterized by the removal of a halogen atom and a hydrogen atom from adjacent carbons, resulting in the formation of an alkene.

Step 2: Analyzing the options.
(A) NaNO\(_2\) + HCl: This is not used in the Hoffmann elimination reaction. Instead, it is used in diazotization reactions.
(B) CH\(_3\)COCl: This is an acylation reagent, used in reactions like Friedel-Crafts acylation, not for Hoffmann elimination.
(C) Ag\(_2\)O/H\(_2\)O, \(\Delta\): Correct — This is the correct reagent for the Hoffmann elimination reaction. Ag\(_2\)O (silver oxide) in water and heat (\(\Delta\)) promotes the elimination of a halogen from an amine to form an alkene.
(D) CHCl\(_3\) + KOH: This combination is not related to the Hoffmann elimination reaction; it is typically used in other organic reactions, such as the formation of chloroform.

Step 3: Conclusion.
The correct answer is (C) Ag\(_2\)O/H\(_2\)O, \(\Delta\), as these are the reagents required for the Hoffmann elimination reaction.