Skip to main content
Library homepage
 

Text Color

Text Size

 

Margin Size

 

Font Type

Enable Dyslexic Font
Chemistry LibreTexts

Ortho, Para Directing Group

( \newcommand{\kernel}{\mathrm{null}\,}\)

A monosubstituted benzene, when treated with an electrophile, could undergo three electrophilic aromatic substitution reactions. Each reaction yields a disubstituted benzene as the organic product, which can be identified using the descriptors ortho, meta, and para (see ortho carbon).

orthoparadirectinggroup1.png

A = any substituent
E+ = electrophile

If the relative yield of the ortho product and that of the para product are higher than that of the meta product, the substituent on the benzene ring in the monosubstituted benzene is called an ortho, para directing group. If the opposite is observed, the substituent is called a meta directing group.

eg. 1:

orthoparadirectinggroup2.png

Thus, the methyl group is an ortho, para directing group.

eg. 2:

orthoparadirectinggroup3.png

Thus, the nitro group is a meta directing group.

Ortho, para directing groups are electron-donating groups; meta directing groups are electron-withdrawing groups. The halide ions, which are electron-withdrawing but ortho, para directing, are the exception.

Common ortho, para directing groups:

orthoparadirectinggroup4.png

Common meta directing groups:

orthoparadirectinggroup5.png

see also activating group, deactivating group


This page titled Ortho, Para Directing Group is shared under a All Rights Reserved (used with permission) license and was authored, remixed, and/or curated by Gamini Gunawardena via source content that was edited to the style and standards of the LibreTexts platform.

  • Was this article helpful?

Support Center

How can we help?