Chapter 19.13, Problem 35CC

Interpretation Introduction

Interpretation:

The product of the following reaction has to be predicted –

                                     

Concept Introduction:

• Apart from electrophilic substitution reactions, aromatic compounds undergo another type of reactions namely Aromatic nucleophilic substitution reactions.

• A nucleophile, unlike an electrophile is a species that is electron rich and always attracted towards electron deficient site. A nucleophile is mobile unlike electrophile.

• In aromatic compounds the site in the ring where there is deficient of electrons is attacked by the nucleophile. A new $\text{C-Nu}$ bond is formed where ‘Nu’ is the nucleophile and ‘C’ is aromatic ring Carbon. In this process the bond between aromatic Carbon and the substituent bonded with it is broken.

• Let the substituent be ‘X’ that then $\text{C-X}$ bond gets broken and  $\text{C-Nu}$ bond is formed. The substituent ‘X’ is termed as ‘Leaving group’. A good leaving is large in size with high electron affinity that they are capable to grabbing the bond pair electron and leaving form the aromatic C atom. Halogens are known to be excellent leaving group.

• The overall reaction can be represented as follows –