Question

Identify the carboxylic acid chloride that might be used in a Friedel–Crafts acylation reaction to prepare each of the following acylbenzenes:

a.

b.

Short answer

a.

b.

Step-by-step solution

FriedelCrafts acylation

FriedelCrafts acylation reaction involves the introduction of acyl group into the benzene ring. The benzene ring reacts with carboxylic acid chloride in the presence of${\mathbf{AlCl}}_3$ to yield acylbenzene in this reaction.

Carboxylic acid chloride used in the formation of the acylbenzene

To identify the carboxylic acid chloride used in Friedalcraft’s acylation of benzene, the bond between benzene and ketone carbon is broken and replaced with $-Cl$.

(a)The following acyl benzene, 2-methyl-1-phenylpropan-1-one can be produced by reacting benzene with isobutyryl chloride in the presence of $AlC{l}_3$.The carboxylic acid chloride used in this reaction is isobutyryl chloride. The reaction can be given as:

Reaction (a)

(b)The following acylbenzene, benzophenone can be produced by reacting benzene with benzoyl chloride in the presence of $AlC{l}_3$. The carboxylic acid chloride used in this reaction is benzoyl chloride. The reaction can be given as:

Reaction (b)