The sulfonation of benzene is typically achieved by reacting with fuming sulfuric acid, which is a mixture of H2SO4 and sulfur trioxide (SO3) known as oleum. The reaction follows an electrophilic aromatic substitution mechanism, producing benzenesulfonic acid. The … Read more
In today’s post, we will talk about the chlorination and bromination of benzene via electrophilic aromatic substitution. Remember, in the introductory post about aromatic compounds, we mentioned that, unlike alkenes, dienes, and other conjugated systems, benzene does not react with … Read more
Nitration of benzene or its derivatives introduces a nitro (NO2) group into the aromatic system. The reaction is carried out with a mixture of nitric and sulfuric acids at temperatures above 50 oC. The role of sulfuric acid … Read more
We have learned that activating groups are ortho, para directors, and the meta product for these benzene derivatives is obtained only in negligible quantities. To obtain a meta-substitution product, a deactivating group such as a nitro or a carbonyl group is needed. … Read more
Preparation of Aniline There are a few main ways of preparing aniline: Reduction of the Nitro Group We can add a nitro group to benzene or its derivative via a standard nitration using HNO3 and H2SO4, and then reduce the … Read more
Preparation of Phenols Phenols can be prepared industrially by a substitution reaction of aryl halides under extreme conditions: This is a type of nucleophilic aromatic substitution via a benzyne intermediate: Milder conditions suitable for laboratory preparation … Read more
Remember, earlier, we discussed the Friedel–Crafts acylation reaction, which is used for preparing aryl ketones by reacting aromatic compounds with an acyl halide in the presence of a Lewis acid catalyst. Now, here is a question: how can … Read more
In the last few articles, we talked about the key electrophilic aromatic substitution reactions and the synthetic strategies based on the ortho, meta, para directing effects. Below is a summary of electrophilic aromatic substitution practice problems from different topics. … Read more
In the previous post, we talked about the nucleophilic aromatic substitution, looking at the specifics of the mechanism, regiochemistry, and the limitations. Below are some additional examples to practice these concepts.
We have seen that most reactions of aromatic compounds involve electrophilic substitutions because the π electrons make the aromatic ring electron-rich and therefore, nucleophilic. However, some aryl halides with a strong electron-withdrawing substituent(s) on the ring can undergo nucleophilic substitution … Read more
