Comprehension
The reaction of amines with mineral acids to form ammonium salts shows that these are basic in nature. Aliphatic amines are stronger bases than ammonia whereas aromatic amines are weaker bases than ammonia. Aliphatic and aromatic primary and secondary amines react with acid chlorides, anhydrides and esters by nucleophilic substitution reaction. The main problem encountered during electrophilic substitution reactions of aromatic amines is that of their high reactivity. Substitution tends to occur at ortho- and para-positions. Hinsberg reagent is used for the identification and distinction between primary, secondary and tertiary amines. Aryldiazonium salts, usually obtained from arylamines, undergo replacement of the diazonium group with a variety of nucleophiles to provide advantageous methods for producing aryl halides, cyanides, phenols and arenes.
Question: 1

Write structural formulae of the compound A and B:
CH3CONH2 ⟶ (NaOBr) A
A ⟶ (C6H5COCl / Base) B

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CH 3 CONH 2 (acetamide) with NaOBr undergoes the Hofmann bromamide degradation reaction. In this reaction the amide loses its carbonyl carbon as carbonate and gives a primary amine with one carbon less.
Updated On: Jun 16, 2026
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Solution and Explanation

Step 1: Look at the first reagent.
\(CH_3CONH_2\) (acetamide) is treated with NaOBr, which is the same as Br\(_2\) plus NaOH. This is the Hofmann bromamide degradation.

Step 2: What this reaction does.
In Hofmann degradation an amide loses its carbonyl carbon and is turned into a primary amine with one carbon less than the starting amide.

Step 3: Find A.
Acetamide has 2 carbons. Removing the carbonyl carbon leaves a one carbon amine, methanamine. So \(A = CH_3-NH_2\) (methylamine).

Step 4: Second reagent.
A is then treated with benzoyl chloride \((C_6H_5COCl)\) in the presence of a base. This is benzoylation (an acylation of the amine).

Step 5: Find B.
The N-H of methylamine is replaced by the benzoyl group, giving an N-substituted amide. So \(B = C_6H_5CONHCH_3\) (N-methylbenzamide).

Answer: \(A = CH_3NH_2\) (methanamine) and \(B = C_6H_5CONHCH_3\) (N-methylbenzamide).
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