A) Reimer-Tiemann reaction:
Phenol reacts with chloroform (CHCl\(_3\)) in aqueous sodium hydroxide solution, followed by acidification, to give o-hydroxybenzaldehyde (salicylaldehyde) as the major product.
Matches with IV) Salicylaldehyde. So, A-IV.
B) Etard reaction:
Oxidation of an alkylbenzene (specifically with a methyl group attached to the ring, like toluene) to an aryl aldehyde using chromyl chloride (CrO\(_2\)Cl\(_2\)) in a nonpolar solvent (e. g. , CS\(_2\), CCl\(_4\)), followed by hydrolysis. Toluene \( \rightarrow \) Benzaldehyde.
Matches with I) Benzaldehyde. So, B-I.
C) Sandmeyer reaction:
Conversion of an aryl diazonium salt (ArN\(_2^+\)X\(^-\)) to an aryl halide (Ar-Cl, Ar-Br) or aryl cyanide (Ar-CN) using cuprous salts (CuCl, CuBr, CuCN) respectively. For example, benzenediazonium chloride \( \xrightarrow{CuCl/HCl} \) Chlorobenzene.
Matches with III) Chlorobenzene. So, C-III.
D) Friedel-Crafts reaction:
This refers to either Friedel-Crafts alkylation (Ar-H + R-X \( \xrightarrow{AlCl_3} \) Ar-R) or Friedel-Crafts acylation (Ar-H + RCO-X \( \xrightarrow{AlCl_3} \) Ar-COR).
The product list includes Acetophenone (Ph-CO-CH\(_3\)). This is formed by Friedel-Crafts acylation of benzene with acetyl chloride (CH\(_3\)COCl) or acetic anhydride.
Matches with II) Acetophenone. So, D-II.
The correct matching is:
A - IV
B - I
C - III
D - II
This corresponds to option (3).
