The major products obtained from the reactions in List-II are the reactants for the named reactions mentioned in List-I. Match each entry in List-I with the appropriate entry in List-II and choose the correct option.
- P → 2; Q → 4; R → 1; S → 3
- P → 2; Q → 3; R → 4; S → 1
- P → 5; Q → 3; R → 4; S → 2
- P → 5; Q → 4; R → 2; S → 1
Answer
(2) P → 2; Q → 3; R → 4; S → 1
Solution
(1) Étard reaction gives benzaldehyde, which has no α-H: reactant for Cannizzaro reaction, so S → 1.
[figure] [(ii) H3O+](i) CrO2Cl2/CS2 [figure]
(2) Acid → acid chloride → amide → (dehydration) nitrile: reactant for Stephen reaction, so P → 2.
[figure] PCl5 [figure] NH3 [figure]
P4O10, [figure]
(3) Reduction, then diazotisation gives the diazonium salt: reactant for Sandmeyer reaction, so Q → 3.
[figure] Fe, HCl [figure] NaNO2, HCl, 273-278 K [figure] Cl-
(4) Side-chain chlorination and hydrolysis give benzaldehyde; Tollens' oxidation gives benzoic acid; then acid chloride and amide. Benzamide is the reactant for Hoffmann bromamide degradation, so R → 4.
[figure] Cl2/h [figure] H2O [figure]
Tollens' reagent [figure]
SO2Cl2 [figure] NH3 [figure]
(5) Protection, nitration and deprotection give p-nitroaniline, which is not needed.
[figure] (CH3CO)2O [figure] HNO3, H2SO4 [figure] aq. NaOH [figure]
Answer: (B)