Question

Which of the following is obtained by hydrogenation of benzoyl chloride in presence of Pd on BaSO\(_4\)?

• A. Benzene
• B. Benzoic acid
• C. Benzyl alcohol
• D. Benzaldehyde

Hint:

Rosenmund reduction converts acid chlorides selectively into aldehydes using a poisoned catalyst.

Answer 1

The Correct Option is D

Step 1: Identify the reaction.
Hydrogenation of acid chlorides in the presence of \(\text{Pd/BaSO}_4\) is known as the Rosenmund reduction.

Step 2: Apply Rosenmund reduction.
In this reaction, an acid chloride is selectively reduced to an aldehyde without further reduction to alcohol.

Step 3: Reaction involved.
\[ \text{C}_6\text{H}_5\text{COCl} \xrightarrow[\text{Pd/BaSO}_4]{\text{H}_2} \text{C}_6\text{H}_5\text{CHO} \]

Step 4: Analyze options.
(A) Benzene is not formed in this reaction.
(B) Benzoic acid is not a reduction product.
(C) Benzyl alcohol is not formed due to poisoned catalyst.
(D) Benzaldehyde is the correct product.

Step 5: Conclusion.
Benzaldehyde is obtained by hydrogenation of benzoyl chloride using Pd on BaSO\(_4\).