question_answer

Among the following groups the ortho and para directing group is :

A) \[COCH{{3}_{}}\]             

B) \[~N{{H}_{2}}\]

C) \[~NHCOC{{H}_{3}}\]    

D) ?COOH

Correct Answer: B

Solution :

2 and 6 are ortho position 4 is para position 3 and 5 are meta position with respect to the substituent - X. Aromatic compounds undergo electrophilic substitution reaction. Those groups which increase the electron density on ortho, para position (\[viz,-C{{H}_{3}},-{{C}_{2}}H{{ & }_{5}},-OH,-Br,-N{{H}_{2}},-NHR\]etc.) are called ortho/para directing group substituents, which increases electron density on meta position (\[-N{{O}_{2}},-CN,-CHO,-COR.\]\[-COOH,-COOR,-S{{O}_{3}}H\]etc. are meta directing groups.