Chapter 19.12, Problem 34ATS

Interpretation Introduction

Interpretation:

• Synthesis of the following compound starting from benzene has to be illustrated.

                                 

• The ease of installing the sixth substituent on the above compound has to be analyzed.

• The aromatic ring in the above whether activated or deactivated has to be inferred.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.

• The most common type of reactions that benzene undergoes is electrophilic substitution reactions. An electrophile is a species that is deficient of electrons. So the term electrophilic substitution reactions mean the reactions involving substitution of a group or an atom by electrophile.

• The structure of benzene is described as follows – planar, six memebered cyclic ring made of Carbon and Hydrogen atoms. The skeleton of the ring is made of $\text{C-C}$ bonds. There are 3 $\text{C=C}$ bonds present in benzene ring. Each Carbon is bonded to one Hydrogen atom. Thus there are 3 $\text{C=C}$ bonds, 6 $\text{C-C}$ bonds and 6 $\text{C-H}$ bonds present in benzene.

• In benzene electrophilic substitution reaction involves the reaction between electrophile and $\text{C-H}$ bonds of the benzene. As a consequence, Hydrogen atom in the $\text{C-H}$ bond is substituted by the electrophile.

• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.

• So it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. The key to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.