JEE Main 2022 · 27 Jun · Shift 2 · Chemistry Q74

← JEE Main 2022 · 27 Jun · Shift 2

ChemistrySingle correct+4 / -1Question 74 of 90

Product 'A' of following sequence of reactions is
$\text{Ethylbenzene}\xrightarrow[\text{(c) alc. KOH}]{\text{(a) Br}_2\text{, Fe}\quad\text{(b) Cl}_2,\ \Delta}\underset{\text{Major Product}}{\text{'A'}}$

α-Chlorostyrene, C6H5-C(Cl)=CH2

α-Chlorostyrene: benzene ring bearing C(Cl)=CH2.

α-Bromostyrene, C6H5-C(Br)=CH2

α-Bromostyrene: benzene ring bearing C(Br)=CH2.

1-Bromo-4-(chloroethynyl)benzene

Para-bromophenyl ring bearing a C≡C-Cl group.

4-Bromostyrene, Br-C6H4-CH=CH2 (para)

4-Bromostyrene: vinyl group para to Br on a benzene ring.

Answer and worked solution

Official answer: D

Steps. $\mathrm{Br_2/Fe}$ brominates the ring para to ethyl; $\mathrm{Cl_2}$ with heat chlorinates the benzylic carbon; alcoholic KOH eliminates HCl: 4-bromostyrene.

(D)

Topics:Aromatic hydrocarbons and electrophilic substitution Elimination reactions

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JEE Main 2022 · 27 Jun · Shift 2, Chemistry question 74