See image — Aromatic Hydrocarbons Chemistry Question

💡 Solution & Explanation

Step 1 - Identify the final product and work backwards. The final product is 2-aminophenol (a benzene ring bearing OH and NH2 at ortho positions). The reaction B --> 2-aminophenol uses Br2 + KOH, which is the Hofmann bromamide (Hofmann rearrangement) reaction. This reaction converts a primary amide (RCONH2) to a primary amine (RNH2) with loss of one carbon (as CO2). So B must be a primary amide that gives 2-aminophenol, meaning B is 2-hydroxybenzamide (the amide of 2-hydroxybenzoic acid, i.e., salicylamide): the ring bears OH and CONH2 at ortho positions. Under Hofmann conditions, -CONH2 --> -NH2, giving 2-aminophenol. Step 2 - Identify A from the conversion A --[(i) SOCl2, (ii) NH3]--> B. SOCl2 converts a carboxylic acid to an acid chloride, and then NH3 converts the acid chloride to a primary amide. So A must be the carboxylic acid corresponding to B. Since B is 2-hydroxybenzamide, A is 2-hydroxybenzoic acid (salicylic acid): benzene ring with OH and COOH at ortho positions. Step 3 - Determine which compound on hydrolysis gives A (2-hydroxybenzoic acid). Hydrolysis of an ester gives a carboxylic acid and an alcohol (or phenol). We need hydrolysis to yield 2-hydroxybenzoic acid (salicylic acid) as the acid component. Option (a): 2-nitrophenyl 2-nitrobenzoate — the acid portion is 2-nitrobenzoic acid (NO2 on the acid ring). Hydrolysis gives 2-nitrobenzoic acid, NOT 2-hydroxybenzoic acid. This is wrong. Option (b): 2-nitrophenyl 2-hydroxybenzoate — the structure shows a benzene ring with HO at the ortho position bearing the C=O, esterified with 2-nitrophenol. Hydrolysis gives 2-hydroxybenzoic acid (salicylic acid) + 2-nitrophenol. The acid product is exactly A (2-hydroxybenzoic acid / salicylic acid). This is correct. Step 4 - Confirm. Option (b) on hydrolysis yields 2-hydroxybenzoic acid (A), which upon treatment with SOCl2 then NH3 gives 2-hydroxybenzamide (B), which upon Hofmann rearrangement (Br2/KOH) gives 2-aminophenol as shown. Therefore, the correct answer is B.