Question

In which of the following compounds, an electrophile prefers to attack the meta position?

• A. Phenol
• B. Chlorobenzene
• C. Nitrobenzene
• D. Aniline

Hint:

Common meta-directing groups: \[ -NO_2,\; -CHO,\; -COOH,\; -COR,\; -CN,\; -SO_3H \] Common ortho/para-directing groups: \[ -OH,\; -NH_2,\; -OR,\; -NHR,\; -Cl,\; -Br \]

Answer 1

The Correct Option is C

Step 1: Recall the directing rule.
In aromatic electrophilic substitution, the group already on the ring decides where the electrophile attacks. Electron-donating groups send it to ortho and para, electron-withdrawing groups send it to meta.

Step 2: Look at phenol.
$-OH$ donates electrons by resonance, so it is ortho and para directing, not meta.

Step 3: Look at chlorobenzene.
$-Cl$ withdraws by induction but donates by resonance, and overall it is ortho and para directing. So not meta.

Step 4: Look at aniline.
$-NH_2$ is a strong electron donor by resonance, hence ortho and para directing. Not meta.

Step 5: Look at nitrobenzene.
$-NO_2$ strongly pulls electrons out of the ring, leaving the meta position least deactivated, so it is meta directing.

Step 6: Conclusion.
Only nitrobenzene directs the electrophile to the meta position.
\[ \boxed{\text{Nitrobenzene}} \]