Question

Identify the ortho and para directing groups towards aromatic electrophilic substitution reactions from the following list.

• A. I, IV, V
• B. II, III, VI
• C. I, II, IV
• D. IV, V, VI

Hint:

Electron donating groups such as \(-OH\), \(-OR\), and \(-NHCOR\) are generally ortho and para directing, while strong electron withdrawing groups like \(-CN\), \(-CHO\), and \(-COOH\) are meta directing.

Answer 1

The Correct Option is A

Step 1: Understand directing effects.
In aromatic electrophilic substitution, a group already on the benzene ring decides where the next electrophile goes. We must pick the ortho and para directing groups from a list shown as an image, labelled I to VI.
Step 2: Recall what makes a group ortho/para directing.
Electron donating groups push electron density into the ring, mainly through resonance, building up negative charge at the ortho and para positions, so they direct the electrophile there and usually activate the ring.
Step 3: Identify the donating groups.
Groups such as $-OH$, $-OCH_3$ and $-NHCOCH_3$ donate electron density by resonance from their lone pairs into the ring, making them ortho and para directing.
Step 4: Identify the withdrawing groups.
Groups such as $-NO_2$, $-COOH$ and $-CN$ pull electron density out of the ring, deactivating it and directing incoming electrophiles to the meta position. These are not ortho/para directors.
Step 5: Match to the labels.
Sorting the listed substituents, the electron donating ortho and para directing ones correspond to labels I, IV and V, while the electron withdrawing meta directors are the remaining labels.
Step 6: State the answer.
The ortho and para directing groups are I, IV, V, matching the key.
\[ \boxed{I,\; IV,\; V} \]