Question

Which of the following group(s) is/are ortho and para directing?

• A. $-CN$
  
• B. $-N{O}_2$
  
• C. $-N{H}_2$
  
• D. $-OH$

Answer 1

Answer: (C), (D)

$-OH$

Both $N{H}_2$ and $OH$ shows +R effect. Hence, they donate their lone pair of electrons and increasing the electron density at ortho and para position. This activates the ortho and para position for electrophilic substitution reaction. These groups are called activating groups or ortho/para directing groups.

$CN$ and $N{O}_2$ shows -R effect which decrease the electron density at ortho and para position. Thus, these group are called deactivators or meta directiong groups.