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

a.

b.

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.

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)