Question

An aromatic compound ‘A’ (C₇H₆O₂) on reaction with aqueous ammonia and heating forms compound ‘B’. ‘B’ on heating with Br₂ and alcoholic potash forms a compound ‘C’ of molecular formula C₆H₇N. Write the reactions involved and identify ‘A’, ‘B’, ‘C. 

Answer 1

Given:

Compound A: C₇H₆O₂ (aromatic compound, likely a benzoic acid derivative).
Reaction with aqueous ammonia and heating gives Compound B (likely an amide)
Compound B reacts with Br₂ and alcoholic KOH (Hofmann bromamide reaction) to form Compound C C₆H₇N, a primary aromatic amine.

The molecular formula matches benzoic acid C₆H₅COOH.

Reaction of Compound A with Aqueous Ammonia:

Benzoic acid reacts with aqueous ammonia NH₃ to form benzamide C₆H₅CONH₂ on heating.

\[\ce{C6H5COOH + NH3 -> C6H5CONH2 + H2O}\]

Reaction of Compound B with Br₂ and Alcoholic KOH to form aniline C₆H₅NH₂.

\[\ce{C6H5CONH2 + Br2 + 4KOH −> C6H5NH2 + K2CO3 + 2KBr + 2H2O}\]

• Compound A: C₆H₅COOH (benzoic acid)
• Compound B: C₆H₅CONH₂ (benzamide)
• Compound C: C₆H₅NH₂ (aniline)