Question

Which among the following compounds is treated with benzonitrile to obtain benzophenone in dry ether and then acid hydrolysis?

• A. CH\(_3\)COCH\(_3\)
• B. C\(_6\)H\(_5\)MgBr
• C. C\(_6\)H\(_5\)ONa
• D. CH\(_3\)MgBr

Hint:

Grignard reagents like C\(_6\)H\(_5\)MgBr react with nitriles to form ketones, which can then undergo acid hydrolysis.

Answer 1

The Correct Option is B

Step 1: Understanding the reaction.
In the reaction, benzonitrile reacts with phenyl magnesium bromide (C\(_6\)H\(_5\)MgBr) in dry ether to form benzophenone. The reaction also involves acid hydrolysis to complete the conversion. This is a typical Grignard reaction followed by acid hydrolysis.

Step 2: Analyzing the options.
(A) CH\(_3\)COCH\(_3\): Incorrect — This is acetone, not involved in this reaction.
(B) C\(_6\)H\(_5\)MgBr: Correct — This is phenyl magnesium bromide, which reacts with benzonitrile to form benzophenone.
(C) C\(_6\)H\(_5\)ONa: Incorrect — This is phenoxide, not a suitable reactant in this case.
(D) CH\(_3\)MgBr: Incorrect — This is methyl magnesium bromide, which would not form benzophenone.

Step 3: Conclusion.
The correct answer is (B) C\(_6\)H\(_5\)MgBr, as it is treated with benzonitrile to form benzophenone.