Question

An organic compound [A] has molecular formula C₇H₆O₂. When compound [A] is treated with SOCl₂, it yields compound [B]. On heating with NH₃, compound [B] forms compound [C]. Compound [C] forms compound [D] on reaction with Br₂/KOH. Compound [D] responds to carbylamine test.

Identify compounds [A], [B], [C], and [D].

Answer 1

[A] = Benzoic acid (C₆H₅COOH)

[B] = Benzoyl chloride (C₆H₅COCI)

[C] = Benzamide (C₆H₅CONH₂) 

[D] = Aniline (C₆H₅NH₂)

Explanation: Compound [A] has a benzene ring (C₆H₆) with two oxygen atoms, which indicates that it is benzoic acid according to the chemical formula C₇H₆O₂. Benzoyl chloride is created when benzoic acid and SOCl₂ combine. Benzamide is produced when benzoyl chloride reacts with NH₃. Aniline, which reacts to the carbylamine test, is produced when benzamide undergoes Hoffmann bromamide breakdown with Br₂/KOH.