Question

A nitrogen containing organic compound gave an oily liquid on heating with bromine and potassium hydroxide solution. On shaking the product with acetic anhydride, an antipyretic drug was obtained. The reactions indicate that the starting compound is

• A. Aniline
• B. Benzamide
• C. Acetamide
• D. Nitrobenzene

Answer 1

Answer: (B)

Benzamide

Answer 2

$C_{6}H_{5}CONH_{2} + Br_{2} + KOH \rightarrow C_{6}H_{5}CONHBr + KBr + H_{2}O$

$\mathbf{\downarrow}\mathbf{KOH}$

$\mathbf{K}_{\mathbf{2}}\mathbf{C}\mathbf{O}_{\mathbf{3}}\mathbf{+}\mathbf{C}_{\mathbf{6}}\mathbf{H}_{\mathbf{5}}\mathbf{N}\mathbf{H}_{\mathbf{2}}\overset{\leftarrow}{\mathbf{\quad}\mathbf{2KOH}\mathbf{\quad}}\mathbf{C}_{\mathbf{6}}\mathbf{H}_{\mathbf{5}}\mathbf{NCO + KBr +}\mathbf{H}_{\mathbf{2}}\mathbf{O}$

$\mathbf{C}_{\mathbf{6}}\mathbf{H}_{\mathbf{5}}\mathbf{N}\mathbf{H}_{\mathbf{2}}\mathbf{+ (C}\mathbf{H}_{\mathbf{3}}\mathbf{CO}\mathbf{)}_{\mathbf{2}}\mathbf{O}\mathbf{\rightarrow}\mathbf{C}\mathbf{H}_{\mathbf{3}}\mathbf{CONH}\mathbf{C}_{\mathbf{6}}\mathbf{H}_{\mathbf{5}}\mathbf{+ C}\mathbf{H}_{\mathbf{3}}\mathbf{COOH}$

(Acetanilide antipyretic)