Which of the following can be prepared by Sandmeyer reaction ?
A. ArCl
B. ArF
C. ArBr
D. ArCN
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A, C and D only
In the Sandmeyer reaction, an arenediazonium salt is treated with a copper(I) salt, and the –\( \ce{N2^{+}} \) group is replaced by Cl, Br or CN. Fluorine cannot be introduced this way: aryl fluorides are made by heating the diazonium fluoroborate (Balz–Schiemann reaction).
(A) ArCl — Correct. Made with \( \ce{CuCl/HCl} \).
(B) ArF — Incorrect. Made from the diazonium salt and fluoroboric acid; the fluoroborate decomposes on heating to the aryl fluoride. This is not a Sandmeyer reaction.
(C) ArBr — Correct. Made with \( \ce{CuBr/HBr} \).
(D) ArCN — Correct. Made with \( \ce{CuCN/KCN} \).
NCERT (2026-27 edition):
Replacement by Halide or Cyanide Ion
Replacement by Fluoride Ion
