Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE MainChemistryHydrocarbons

Consider the following sequence of reactions starting from benzene: Benzene CH ₃ CH ₂ CH ₂ Cl, AlCl ₃ P (major) Br ₂ , Fe Q (major) NBS, h R alc. KOH, S (major) The IUPAC name of the final major product 'S' is:

Options

  1. A1-bromo-4-(prop-1-enyl)benzene
  2. B1-bromo-4-(prop-1-en-2-yl)benzene
  3. C1-(2-bromopropan-2-yl)benzene
  4. D1-bromo-2-(prop-1-en-2-yl)benzene

Correct answer

B. 1-bromo-4-(prop-1-en-2-yl)benzene

Step-by-step solution

Step 1: Reaction of benzene with n-propyl chloride and AlCl ₃ generates a primary carbocation ( CH ₃ CH ₂ CH ₂^+ ), which undergoes a 1,2-hydride shift to form a more stable secondary carbocation ( CH ₃ CH ^+ CH ₃ ). Electrophilic aromatic substitution yields isopropylbenzene (cumene) as the major product 'P'. Step 2: Bromination of isopropylbenzene with Br ₂/ Fe occurs via electrophilic aromatic substitution. The bulky isopropyl group directs the incoming bromine predominantly to the para position due to steric hi

Practice Hydrocarbons on Quantrex Academy →

More from Hydrocarbons

In the following reaction sequence, Q , R , S and T are the major products. The correct statement(s) about Q , R , S and T is(are) 2026Treatment of buta-1,3-diyne with NaNH ₂ ( 2 equivalents), followed by reaction with excess of trans - CH ₃ -CH=CH-CH ₂ -Br gives X as the major product. The maximum number of carbo 2026The List-II contains products obtained from the reaction of compounds in List-I with O ₃ /Zn- H ₂ O followed by cyclization (via more stable enolate) in the presence of aqueous NaO 2026Natural rubber on complete ozonolysis ( O ₃ /Zn- H ₂ O ) gives compound X as the major product. X gives positive iodoform and Tollen's tests. X on heating with aqueous NaOH gives Y 2026An optically active alkyl bromide C₄ H₉ Br, reacts with ethanolic KOH to form major compound [A] which reacts with bromine to give compound [B]. Compound [B] reacts with ethanolic 2026An alkane (Y) requires 8 moles of oxygen for complete combustion and on chlorination with Cl₂ /h , (Y) gives only one monochlorinated product (Z) . The total number of primary carb 2026R_f value for 2 -methylpropene in a solvent system (Ethyl acetate + ether) is 0.42 . 2 -methylpropene is treated with dilute H ₂ SO ₄ to give major organic product (X). R_f value f 2026Given below are two statements: Statement I: Methane can be prepared by decarboxylation of sodium ethanoate, Kolbe's electrolysis of sodium acetate and reaction of CH ₃ MgBr with w 2026 Full Hydrocarbons list All JEE Main PYQs