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Starting from p-toluidine (a benzene ring bearing -NH2 and -CH3 groups at para positions), the following reaction sequence is carried out: Step 1: NaNO2 + HCl at 0-5 deg C, then Cu2Cl2 + HCl gives compound [A]. Step 2: [A] treated with Cl2 under UV light (hv) gives compound [B]. Step 3: [B] treated with sodium metal in dry ether (Wurtz conditions) gives the major product [C]. Identify [C].

1. ClCH2-C6H4-C6H4-CH2Cl (with Cl on both benzylic carbons)
2. CH3-C6H4-C6H4-CH3 (4,4'-dimethylbiphenyl)
3. ClCH2-C6H4-C6H4-CH3 (one benzylic Cl, one methyl)
4. CH3-C6H4-C6H4-CH2Cl (one methyl, one benzylic Cl)

Correct answer: ClCH2-C6H4-C6H4-CH2Cl (with Cl on both benzylic carbons)

Solution

p-Toluidine is converted to p-chlorotoluene [A] by Sandmeyer reaction, then free-radical chlorination with Cl2/hv substitutes the benzylic CH3 to give p-chlorobenzyl chloride [B] (Cl-C6H4-CH2Cl). Wurtz coupling of two molecules of [B] with sodium gives [C] = ClCH2-C6H4-C6H4-CH2Cl.

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