Question

Name of the reaction in which benzoyl chloride is converted to benzaldehyde is

• A. Friedel-Crafts acylation
• B. Reduction
• C. Rosenmund reduction
• D. Nucleophilic substitution

Hint:

The Rosenmund reduction is a selective reduction of acyl chlorides to aldehydes, and it involves the use of hydrogen and a palladium catalyst.

Answer 1

The Correct Option is C

The reaction that converts benzoyl chloride to benzaldehyde is called the \textit{Rosenmund reduction}. In this process, benzoyl chloride (C\(_6\)H\(_5\)COCl) is reduced to benzaldehyde (C\(_6\)H\(_5\)CHO) using hydrogen gas (\(H_2\)) in the presence of a palladium on barium sulfate (Pd/BaSO\(_4\)) catalyst. This reduction process selectively reduces the acyl chloride to an aldehyde, without reducing the aromatic ring. - Friedel-Crafts acylation is a reaction where an acyl group is introduced to an aromatic ring using an aluminum chloride (AlCl\(_3\)) catalyst, but it does not convert acyl chlorides into aldehydes. - Reduction in general refers to the process of adding electrons (often involving hydrogen), but it’s not specific to benzoyl chloride. - Nucleophilic substitution refers to a class of reactions where a nucleophile replaces a leaving group, but this is not the mechanism for reducing benzoyl chloride to benzaldehyde. Therefore, the Rosenmund reduction is the correct name for this specific reaction.