In an Organic Chemistry II class you often add groups to aromatic systems. If you’re wondering where the substitution will take place, check out this table for some guidelines. When using this table, remember two things:
O-p-directors always beat m-directors.
Strong activators always beat weak activators.
| Ortho-Para-Directors | |
|---|---|
| Very Strong Activators | -NH2, -NHR, -NR2, -OH, -O– |
| Moderate Activators | -OR, -NH-CO-R, -O-CO-R |
| Weak Activators | -R, -C6H5 |
| Mild Deactivators | -F, -Cl, -Br, -I |
| Meta-Directors | |
| Very Strong Deactivators | -N+R3, -NO2, -CN, -CCl3, -CF3 |
| Moderate to Mild Deactivators | -CN, -SO3H, -CO-R, -COOH, -COOR, -CONH2, -N+H3 |