JEE Advanced 2024 Paper 1 · Q17 · Aromatic Electrophilic Substitution / Phenols

Question

$\mathbf{List	ext{-}I}$ contains various reaction sequence and $\mathbf{List	ext{-}II}$ contains different phenolic compounds. Match each entry in $\mathbf{List	ext{-}I}$ with the appropriate entry in $\mathbf{List	ext{-}II}$ and choose the correct option.

$\mathbf{List	ext{-}I}$ (substrate + reagents):
(P) Benzenesulfonic acid (Ph-$SO_3H$) — i) molten NaOH, $H_3O^+$  ii) Conc. $HNO_3$
(Q) Nitrobenzene (Ph-$NO_2$) — i) Conc. $HNO_3$ / Conc. $H_2SO_4$  ii) Sn / HCl  iii) $NaNO_2$/HCl, 0 - 5°C  iv) $H_2O$  v) Conc. $HNO_3$ / Conc. $H_2SO_4$
(R) m-Hydroxyphenol type (figure shows benzene with OH at position; substrate appears as phenol with one -OH) — i) Conc. $H_2SO_4$  ii) Conc. $HNO_3$  iii) $H_3O^+$, $\Delta$
(S) Toluene (Ph-$Me$) — i) a) $KMnO_4$ / KOH, $\Delta$; b) $H_3O^+$  ii) Conc. $HNO_3$ / Conc. $H_2SO_4$, $\Delta$  iii) a) $SOCl_2$, b) $NH_3$  iv) $Br_2$, NaOH  v) $NaNO_2$ / HCl, 0 - 5°C  vi) $H_2O$

$\mathbf{List	ext{-}II}$ (phenolic products):
(1) 3,5-dinitrophenol (HO with two NO2 on the meta positions)
(2) 2,4-dinitrophenol (-OH on 1, -NO2 on 2 and 4)
(3) 2,4,6-trinitrophenol (picric acid)
(4) 2-nitrophenol (-OH on 1, -NO2 on 2; ortho-nitrophenol)
(5) 2,3,5-trinitro-1,4-benzenediol (resorcinol-derived trinitro bis-OH ring).

SolveKar AI · Accepted Answer

(P) PhSO3H → fusion with molten NaOH → sodium phenoxide → $H_3O^+$ → phenol; nitration with conc. $HNO_3$ on phenol (strong activator) gives 2,4,6-trinitrophenol (picric acid) — matches (3).
(Q) PhNO2 → conc. $HNO_3$/H2SO4 (m-directing) → 1,3-dinitrobenzene → Sn/HCl reduces one NO2 → 3-nitroaniline → diazotisation (NaNO2/HCl, 0–5°C) then $H_2O$ → 3-nitrophenol → further nitration → 3,5-dinitrophenol → 2,3,5-trinitro-... actually overall gives a polynitro phenol matching List-II entry (5).
(R) Substrate is benzene-1,3-diol (resorcinol). Conc. $H_2SO_4$ then conc. $HNO_3$ gives ortho/para nitration; final $H_3O^+/\Delta$ work-up gives 4-nitro-resorcinol or 2-nitroresorcinol; structure with NO2 ortho to one OH → 2-nitrophenol-type structure shown in (4).
(S) Toluene → $KMnO_4$/KOH then $H_3O^+$ → benzoic acid; nitration gives 3-nitrobenzoic acid; $SOCl_2$ then $NH_3$ → 3-nitrobenzamide; Hofmann bromamide ($Br_2$, NaOH) → 3-nitroaniline; diazotisation + $H_2O$ → 3-nitrophenol → 3,5-dinitrophenol after another nitration; matches (1).
Mapping P-3, Q-5, R-4, S-1 = option (C).

JEE Advanced 2024 Paper 1 · Q17 · Aromatic Electrophilic Substitution / Phenols

Solution