See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1: Identify the functional group. The structure contains a C=O group bonded to an NH, making it an amide. Step 2: Identify the acyl (carbonyl) side chain. Starting from the carbonyl carbon, we count: C(=O)-CH2-CH2-CH2-Cl. This is a 4-carbon chain with a chloro substituent at C4 (the terminal carbon). The parent acid would be 4-chlorobutanoic acid, so the acyl portion is named '4-chlorobutanamide'. Step 3: Identify the N-substituent. On the nitrogen side: NH-CH2-CH2-CH(Cl)-CH3. Counting from the nitrogen: C1 is CH2, C2 is CH2, C3 is CH(Cl), C4 is CH3. This is a 4-carbon chain (butyl) with a chloro group at C3 (counting from the nitrogen attachment point). Wait, re-examine: NH-CH2-CH2-CH(Cl)-CH3 — the nitrogen is attached to C1(CH2), then C2(CH2), then C3(CH(Cl)), then C4(CH3). So this is a 3-chlorobutyl group. Step 4: Assemble the name. The compound is an amide where the acyl group comes from 4-chlorobutanoic acid and the N-substituent is a 3-chlorobutyl group. The full IUPAC name is: 4-chloro-N-(3-chlorobutyl)butanamide. Step 5: Verify numbering. For the N-substituent, numbering starts at the carbon attached to nitrogen: C1-C2-C3(Cl)-C4(Me), confirming '3-chlorobutyl'. For the acyl chain, numbering starts at the carbonyl carbon: C1(C=O)-C2-C3-C4(Cl), confirming '4-chlorobutanamide'. Therefore, the correct answer is 4-chloro-N-(3-chlorobutyl)butanamide.