Which of the given reaction cannot be used to prepare aromatic nitriles ( A r C N ) ?

Step-by-step solution

Halogen have - I and + M effect by which its electron delocalized in benzene ring by resonance & due to its - I effect its bonded with benzene ring and cannot be substitute by C N - & show the inertness against nucleophilic substitution with K C N while other option gives Aromatic nitrile A r N 2 + + C u C N → A r C N + N 2 + C u + A r C O N H 2 → P 2 O 5 A r C N A r C O N H 2 + S O C l 2 → A r C N + S O 2 + 2 H C l