ABC26OR0029 · General Organic Chemistry
Subject: Organic Chemistry · Chapter: General Organic Chemistry · Topic: Aromaticity · Exam: CSIR-NET DEC 2013 · Marks: 2 · Difficulty: Medium
The correct order for the rates of electrophilic aromatic substitution of the following compound is 
(I) (II) (III)
(I) (II) (III)(a)I $>$ II $>$ III
(b)II $>$ I $>$ III
(c)III $>$ II $>$ I
(d)I $>$ III $>$ II
Answer
Answer (as printed): D
Explanation
Pyridine (II) will be more prone to nucleophilic aromatic substitution than electrophilic. Nitrogen in pyridine decreases the electron density of the ring. In (I), the nitrogen donates its lone pair to the ring thus increasing the electrophilicity of the ring. Hence it is most prone to electrophilic aromatic substitution.