In this experiment, you will study the activating/deactivating and directing effects of substituent groups on an aromatic ring when the ring undergoes additional electrophilic aromatic substitution. In the class lecture, you will learn that substituents are introduced onto an aromatic ring by means of an electrophilic aromatic substitution reaction. This reaction involves a resonance-stabilized cationic intermediate shown below.
Electrophile
Substituents on the ring can stabilize or destabilize the resultant cationic intermediate, so we classify these substituents as either activators or deactivators, respectively. This will direct the incoming electrophile to a particular ring position, so we classify substituents as either ortho-para-directors or meta-directors.
In this experiment, we will be introducing an iodo-substituent to a ring that is already substituted with two groups, each with their own activating/deactivating and directing behavior. The possible products for the iodination of salicylamide (2-hydroxybenzamide) are shown below:
OH
OH
OH
OH
OH
NH2
NH2
NH2
NH2
NH2
