Question

Which one of following is incorrect statement about above reaction?

• A. If R is $C{u}_{2}C{l}_2/HCl$ the (P) is same as (A)
• B. If R is $HB{F}_4/\Delta$ then (P) is fluorobenzene
• C. If R is $KI$ then (P) is iodobenzene
• D. If R is $KBr$ then (P) is bromobenzene

Answer 1

The correct option is D If R is $KBr$ then (P) is bromobenzene

Option (d) is the answer.
Explanation :
Conversion of (A) to (B) proceeds through Benzyne mechanism. (B) upon treatment with $NaN{O}_2/HCl$ produces benzenediazonium chloride (C) as follow:

As per options provided here
(a.) (A) will be the product when R is $CuCl/HCl$


(b.) Fluorobenze will be the product when R is $HB{F}_4$ (fluoroboric acid).


(c.) Iodobenzene will be the product when R is $KI$.


(d.) Bromobenzene will be the product if R is $C{u}_{2}B{r}_2/HBr$ not $KBr$.