IIT-JEE 2007 · Paper 1 · Chemistry Q26

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ChemistrySingle correct+3 / -1Question 26 of 66

In the following reaction, the structure of the major product 'X' is

Benzanilide $\xrightarrow[\text{conc. }\ce{H2SO4}]{\text{conc. }\ce{HNO3}}$ X

Benzanilide (Ph-NH-CO-Ph) treated with conc. HNO₃/conc. H₂SO₄ to give X.

N-Phenyl-3-nitrobenzamide: NO₂ meta on the benzoyl ring.

N-(4-Nitrophenyl)benzamide: NO₂ para on the anilide (N-phenyl) ring.

N-Phenyl-4-nitrobenzamide: NO₂ para on the benzoyl ring.

N-(3-Nitrophenyl)benzamide: NO₂ meta on the anilide ring.

Answer and worked solution

Official answer: B

Which ring is activated? In benzanilide $\ce{Ph-NH-CO-Ph}$ the NH group donates its lone pair into the N-phenyl ring (an -NHCOR group is a moderate ortho/para director), while the C=O group withdraws from the benzoyl ring.

Nitration therefore occurs on the anilide ring, mainly at the less hindered para position: N-(4-nitrophenyl)benzamide.

(B)

Topics:Aromatic hydrocarbons and electrophilic substitution Electronic effects (inductive, resonance, hyperconjugation)

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IIT-JEE 2007 · Paper 1, Chemistry question 26