Substituents on an aromatic ring can have several effects on electrophilic aroma
ID: 987479 • Letter: S
Question
Substituents on an aromatic ring can have several effects on electrophilic aromatic substitution reactions. Substituents can activate or deactivate the ring to substitution, donate or withdraw electrons inductively, donate or withdraw electrons through resonance, and direct substitution either to the ortho/para or to the meta positions. From the following lists, select the substituents that have the indicated property. The substituents are written as -XY, where X is the atom directly bound to the aromatic ring.
(1) Activation of the ring toward substitution
-NHCOCH3, -Cl, -OCOCH3, -CN
(2) Withdrawal of electrons through resonance
-OH, -OCH3, -NO2, SO3H
(3) Ortho/para-directed substitution
-CN, -Br, -SO3H, -NHCOCH3, -CH3
Explanation / Answer
(1). Electron donating substituents activate the benzene ring toward substitution. Among the following given groups, the electron donating groups that will activate the ring are:
-NHCOCH3 and -OCOCH3
(2). Groups which deactivates teh ring toward substitution and withdraw electrons through resonance are:
-NO2 and SO3H
(3). Groups which favours the Ortho/para-directed substitution are:
-NHCOCH3 and -CH3