Starting from toluene, propose a synthesis of this trisubstituted benzene

A chemical reaction in which one functional group in a chemical compound replaced another functional group.is known as substitution reaction. It is classified into two types i.e, electrophilic substitution reaction and nucleophilic substitution reaction.

By sulphonation of toluene we can substitute SO₃H to the para position of the benzene ring as methyl is a ortho, para directing group.SO₃H is a meta director. Then by the addition of nitric acid we can substitute nitro group to the ring at the ortho position.

Then by permanganate oxidation we can add –COOH group in place of methyl group.

We have to removeSO₃H from the compound to get the desired product. And nitro group can be reduced to amino group to obtain the final product.