NEET 2023 Phase 2 · ChemistryPrevious Year Question

Choose the correct sequence of reagents for the conversion of 4-nitrotoluene to 2-bromotoluene.

Answer: (A) (A) $Br X_{2}$ ; $Sn / HCl$ ; $NaNO X_{2} / HCl$ ; $H X_{2} O / H X_{3} PO X_{2}$ . Starting from 4-nitrotoluene the $- NO X_{2}$ is a strong o,p-director, so brominating first ( $Br X_{2}$ ) installs Br ortho to the methyl (the eventual 2-position).

A.(A) $Br X_{2}$ ; $Sn / HCl$ ; $NaNO X_{2} / HCl$ ; $H X_{2} O / H X_{3} PO X_{2}$ ✓
B.(B) $Sn / HCl$ ; $Br X_{2}$ ; $NaNO X_{2} / HCl$ ; $H X_{2} O / H X_{3} PO X_{2}$
C.(C) $NaNO X_{2} / HCl$ ; $Sn / HCl$ ; $Br X_{2}$ ; $H X_{2} O / H X_{3} PO X_{2}$
D.(D) $Sn / HCl$ ; $NaNO X_{2} / HCl$ ; $Br X_{2}$ ; $H X_{2} O / H X_{3} PO X_{2}$

Correct Answer

(A) (A) $Br X_{2}$ ; $Sn / HCl$ ; $NaNO X_{2} / HCl$ ; $H X_{2} O / H X_{3} PO X_{2}$

Solution & Explanation

Starting from 4-nitrotoluene the $- NO X_{2}$ is a strong o,p-director, so brominating first ( $Br X_{2}$ ) installs Br ortho to the methyl (the eventual 2-position). $Sn / HCl$ then reduces $- NO X_{2}$ to $- NH X_{2}$ ; $NaNO X_{2} / HCl$ diazotises it; and $H X_{3} PO X_{2} / H X_{2} O$ carries out reductive deamination (replacing $- N X_{2} X^{+}$ by $- H$ ), removing the nitrogen handle and leaving 2-bromotoluene.

🎯

43,000+ questions in हिंदी & English · one-tap toggle

Practice NEET 2023 Phase 2 Chemistry — free, with instant solutions

43,000+ NEET questions solved step-by-step, chapter-wise, in the MedicNEET app.

Open →📚Practice all NEET Chemistry PYQs chapter-wise →💡Don't get it? Learn the Haloalkanes And Haloarenes concepts →

← Chemistry Q11 Chemistry Q13 →

More NEET PYQ solutions

ChemIdentify the suitable reagent for the following conversion: C6H5COOCH3 -> C6H5CHO (methyl benzoate to benzaldehyde)ChemThe correct order of decreasing acidity of the following aliphatic acids is ChemThe major product of the following reaction is: 4-oxo-4-phenylbutanenitrile C6H5-CO-CH2-CH2-CN is treated with (i) CH3MgBr (excess) and then (ii) H3O+.ChemOut of the following complex compounds, which compound will have the minimum conductance in solution?ChemWhich of the following are paramagnetic? A. [NiCl4]^2- B. Ni(CO)4 C. [Ni(CN)4]^2- D. [Ni(H2O)6]^2+ E. Ni(PPh3)4 ChemThe correct order of the wavelength of light absorbed by the following complexes is: A. [Co(NH3)6]^3+ B. [Co(CN)6]^3- C. [Cu(H2O)4]^2+ D. [Ti(H2O)6]^3+ChemThe correct order of decreasing basic strength of the given amines is: (N-ethylethanamine = (C2H5)2NH; ethanamine = C2H5NH2; N-methylaniline = C6H5NH(CH3); benzenamine/aniline = C6H5NH2)ChemPredict the major product P in the following sequence of reactions. The starting material is 1-methylcyclopent-1-ene: (i) HBr, benzoyl peroxide; (ii) KCN; (iii) Na(Hg)/C2H5OH P (major). The structures of the options (A)-(D) are shown in the image below:

More: All NEET 2023 Phase 2 Chemistry PYQs · NEET Chemistry PYQs · All NEET PYQs · Previous year papers