The correct order of the following compounds showing increasing tendency towards nucleophilic substitution reaction is: (i) (see structure) (ii) (see structure) (iii) (see structure) (iv) (see structure)iiiiiiiv
(A)(iv) < (i) < (iii) < (ii)
(B)(iv) < (iii) < (ii) < (i)
(C)(i) < (ii) < (iii) < (iv)✓ Correct
(D)(iv) < (i) < (ii) < (iii)
Answer: (C)
Solution
Nucleophilic aromatic substitution is favored by electron-withdrawing groups (EWGs) that stabilize the negative charge in the Meisenheimer intermediate. (i) Chlorobenzene has no EWG, so it's least reactive. (ii) p-nitrochlorobenzene has one NO₂ group activating the ring. (iii) 2,4-dinitrochlorobenzene has two NO₂ groups. (iv) 2,4,6-trinitrochlorobenzene has three NO₂ groups, making it most reactive. Increasing order: (i) < (ii) < (iii) < (iv). Answer: (C).
JEE Main · 2021 · 24 Feb 2021 · Shift 2 · Single correct option
