Question

How would you synthesize the following compound starting from benzene? More than one step is needed.

Short answer

It is the process of adding alkyl by replacing hydrogen in the aromatic ring. It is the electrophilic aromatic substitution reaction of the arene with the alkyl chloride.

Benzene first reacts with methyl chloride to form methylbenzene.

Step-by-step solution

Step-by-Step SolutionStep1:  Friedel craft alkylation

It is the process of adding alkyl by replacing hydrogen in the aromatic ring. It is the electrophilic aromatic substitution reaction of the arene with the alkyl chloride.

Benzene first reacts with methyl chloride to form methylbenzene.

 Nitration

Nitration occurs in the presence of nitrous acid with sulphuric acid which leads to direct substitution of the nitro group at the para position of 1-methyl benzene.

 Reaction with potassium permanganate

Potassium permanganate is a reagent used for the reduction of the methyl group to the carboxylic acid followed by hydrolysis.

 Formation of 4-nitrobenzoic acid

Steps followed in the formation of 4-nitrobenzoic aid are as follows:

1. Friedel craft alkylation
2. Nitration
3. Reduction with potassium permanganate

Formation of 4-nitrobenzoic acid