Question

Knowing that the sulfonation of benzenes with sulfuric acid is a reversible process, explain how you could leverage this to allow you to make just 1-(1,1-dimethylethyl)-2-nitrobenzene from (1,1-dimethylethyl)benzene.

Answer 1

Answer:

1-(1,1-dimethylethyl)-2-nitrobenzene from (1,1-dimethylethyl)benzene can be made in three steps as mentioned below.

Explanation:

(1,1-dimethylethyl)benzene is sulphonated first. Here $SO_{3}H$ groups add onto para position to 1,1-dimethylethyl group due to electron donating effect and bulky size of 1,1-dimethylethyl group.

In the second step, nitration of the resulting compound is done. Here nitro group adds onto ortho position to 1,1-dimethylethyl group due to combined presence of ortho orienting 1,1-dimethylethyl group and para orienting $SO_{3}H$ group.

Then the resulting compound was heated in presence of strong acid. As sulphonation is a reversible process therefore $SO_{3}H$ group leaves benzene ring in this condition.

Schematic represention has been shown below.