See image — Aromatic Hydrocarbons Chemistry Question

💡 Solution & Explanation

Concept: Electrophilic Aromatic Substitution (EAS) and the directing effects of substituents on a benzene ring. Step 1: Identify the product. The product shown is bromobenzene with a nitro group (NO2) substituent. The structure appears to be o-bromonitrobenzene or m-bromonitrobenzene based on the drawing, but given the context of the question, the product is a nitrobromobenzene (specifically, the product of nitration of bromobenzene). Step 2: Determine the best synthetic route. The product is a nitrated bromobenzene. There are two possible routes: - Route A: Start with bromobenzene (C6H5Br) and perform nitration using HNO3 and H2SO4 (mixed acid). - Route B: Start with nitrobenzene (C6H5NO2) and perform bromination using Br2/FeBr3. Step 3: Consider directing effects. - In bromobenzene (C6H5Br), the Br substituent is an ortho/para director. Nitration with HNO3/H2SO4 introduces NO2 at ortho or para positions relative to Br. This gives o-bromonitrobenzene and p-bromonitrobenzene as major products. - In nitrobenzene (C6H5NO2), the NO2 substituent is a meta director and deactivator. Bromination with Br2/FeBr3 would give m-bromonitrobenzene. Step 4: Identify which product is shown. The structure in the image shows the NO2 group positioned in a way consistent with ortho or para substitution relative to Br, which matches the product obtained from option (a). Step 5: Eliminate other options. - Option (b): C6H5Br + H2SO4, heat would give sulfonation, not nitration. - Option (c): C6H5NO2 + Br2, FeBr3 would give meta product (m-bromonitrobenzene), not ortho/para. - Option (d): C6H5NO2 + HBr is not a valid EAS reaction under normal conditions. Step 6: Option (a) uses bromobenzene with the mixed acid (HNO3, H2SO4), which is the classic nitration condition. Since Br is an o/p director, this gives the ortho and para nitrobromobenzene products shown. Therefore, the correct answer is A.