Substituents on an aromatic ring can have several effects on electrophilic aroma
ID: 505878 • 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.Explanation / Answer
Activation of ring towards substitution:
-CH3 activates by +I effect
-SO3H deactivates due to -M effect
-NHCOCH3 activates by +M effect
-Cl activates by +M effect
Answer:
-CH3, -NHCOCH3, -Cl
withdrawal of electrons through resonance:
-OCH3 donates by +M effect
-CN withdraws due to -M effect
-NH2 donates by +M effect
-COOH withdraws due to -M effect
Answer: -CN , -COOH
ortho/para directed:
-CH3 shows +H effect and hence O/P directing
-NO2 shows -M effect and hence M directing
-COOH shows -M effect and hence M directing
-OH shows +M effect and hence O/P directing
-Cl shows +M effect and hence O/P directing
Answer: -CH3, -OH, -Cl