Synthesis of Mono-Substituted Benzenes:

Some substituents cannot be introduced straight onto an aromatic ring through electrophilic substitution. These involve the following groups -

• NH₂,
• -NHR,
• NR₂,
• NHCOCH₃,
• CO₂H,
• CN,
• OH.

Even though these groups cannot be added directly onto the aromatic ring they can be acquired through transforming a functional group that can be applied directly through electrophilic substitution. Three of the most significant transformations are displayed in figure.

Figure: Functional group transformations of importance in aromatic chemistry.

Nitro, alkyl, and acyl groups can willingly be added via electrophilic substitution and can then be transformed to amino, carboxylic acid, and alkyl groups correspondingly. One time the amino and carboxylic acid groups have been acquired, they can be further transformed to a large range of other functional groups like secondary and tertiary amines, amides, diazonium salts, halides, nitriles, esters, phenols, alcohols, and ethers.