Question

In the following reaction the reagent A is,
\[ {Ar-N2^+X^- →[A] Ar-N2^+BF4^- →[\Delta] Ar-F + BF3 + N2} \]

• A. hydrofluoric acid
• B. boron trifluoride
• C. boric acid
• D. fluoroboric acid

Hint:

Schiemann reaction specifically uses fluoroboric acid to introduce fluorine into aromatic compounds.

Answer 1

The Correct Option is D

Step 1: Identify the reaction.
The given reaction is the Schiemann reaction, which is used to prepare aryl fluorides from aryl diazonium salts.
Step 2: Role of reagent A.
Fluoroboric acid converts the aryl diazonium salt into aryl diazonium tetrafluoroborate, which is a stable intermediate.
Step 3: Heating the intermediate.
On heating, aryl diazonium tetrafluoroborate decomposes to form aryl fluoride, boron trifluoride, and nitrogen gas.
Step 4: Conclusion.
The reagent A used in the given reaction is fluoroboric acid.