The correct answer is Option (2) → (A), (B) and (C) only
Hoffmann bromamide degradation converts amides into primary amines using bromine and a strong base such as NaOH.
General reaction: RCONH₂ + Br₂ + NaOH → RNH₂ + CO₂
- (A) Used to prepare primary amines: This is the primary purpose of the reaction. An amide ($R-CONH_2$) is converted into a primary amine ($R-NH_2$). It is a very useful "stepping-down" reaction in organic synthesis.
- (B) Amides are treated with bromine in aqueous solution: Bromine ($Br_2$) is a required reagent. It reacts with the amide to form an $N$-bromoamide intermediate.
- (C) NaOH is used in this reaction: A strong base, typically sodium hydroxide ($NaOH$) or potassium hydroxide ($KOH$), is essential. The base is needed to deprotonate the amide and to facilitate the rearrangement of the alkyl/aryl group from the carbonyl carbon to the nitrogen.
- (D) HCl is used in this reaction: This is incorrect. The reaction occurs under strongly basic conditions. Adding hydrochloric acid ($HCl$) would neutralize the base and stop the reaction.
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