Matching Named Reactions with Reactants Formed from Organic Chemical Transformations

To find the correct match between List-I (named reactions) and List-II (reactions yielding reactants for List-I), let us analyze the products formed in each reaction of List-II:

1. Reaction (1): $\text{Acetophenone } (\text{C}_6\text{H}_5\text{COCH}_3) \xrightarrow{\text{Zn-Hg, HCl}} \text{Ethylbenzene } (\text{C}_6\text{H}_5\text{CH}_2\text{CH}_3)$ This is a Clemmensen reduction that yields ethylbenzene.

2. Reaction (2): $\text{Toluene } (\text{C}_6\text{H}_5\text{CH}_3) \xrightarrow[\text{(ii) SOCl}_2]{\text{(i) KMnO}_4, \text{ KOH}, \Delta} \text{Benzoyl chloride } (\text{C}_6\text{H}_5\text{COCl})$ Oxidation of toluene yields benzoic acid ($\text{C}_6\text{H}_5\text{COOH}$), which on treatment with thionyl chloride ($\text{SOCl}_2$) produces benzoyl chloride ($\text{C}_6\text{H}_5\text{COCl}$).

3. Reaction (3): $\text{Benzene } (\text{C}_6\text{H}_6) \xrightarrow[\text{anhyd. AlCl}_3]{\text{CH}_3\text{Cl}} \text{Toluene } (\text{C}_6\text{H}_5\text{CH}_3)$ This is a Friedel-Crafts alkylation reaction that produces toluene.

4. Reaction (4): $\text{Aniline } (\text{C}_6\text{H}_5\text{NH}_2) \xrightarrow[273-278\text{ K}]{\text{NaNO}_2/\text{HCl}} \text{Benzenediazonium chloride } (\text{C}_6\text{H}_5\text{N}_2^+\text{Cl}^-)$ This is a diazotization reaction that produces benzenediazonium chloride.

5. Reaction (5): $\text{Phenol } (\text{C}_6\text{H}_5\text{OH}) \xrightarrow{\text{Zn, } \Delta} \text{Benzene } (\text{C}_6\text{H}_6)$ Reduction of phenol with zinc dust yields benzene.

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Now, matching the reactants required for the named reactions in List-I:

• (P) Etard reaction:

  • Reactant required: Toluene ($\text{C}_6\text{H}_5\text{CH}_3$) to form benzaldehyde using chromyl chloride ($\text{CrO}_2\text{Cl}_2$).
  • Toluene is the product of reaction (3).
  • Hence, $\text{P} \rightarrow 3$.

• (Q) Gattermann reaction:

  • Reactant required: Benzenediazonium chloride ($\text{C}_6\text{H}_5\text{N}_2^+\text{Cl}^-$) to form chlorobenzene or bromobenzene using copper powder and halogen acid ($\text{Cu/HCl}$ or $\text{Cu/HBr}$).
  • Benzenediazonium chloride is the product of reaction (4).
  • Hence, $\text{Q} \rightarrow 4$.

• (R) Gattermann-Koch reaction:

  • Reactant required: Benzene ($\text{C}_6\text{H}_6$) to form benzaldehyde using $\text{CO}$ and $\text{HCl}$ in the presence of anhydrous $\text{AlCl}_3/\text{CuCl}$.
  • Benzene is the product of reaction (5).
  • Hence, $\text{R} \rightarrow 5$.

• (S) Rosenmund reduction:

  • Reactant required: Benzoyl chloride ($\text{C}_6\text{H}_5\text{COCl}$) to form benzaldehyde using $\text{H}_2/\text{Pd-BaSO}_4$.
  • Benzoyl chloride is the product of reaction (2).
  • Hence, $\text{S} \rightarrow 2$.

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Conclusion:

The correct match is: $\text{P} \rightarrow 3; \quad \text{Q} \rightarrow 4; \quad \text{R} \rightarrow 5; \quad \text{S} \rightarrow 2$

This corresponds to Option D.