6.1.1 (k,l) Directing Effect

(k) the 2- and 4-directing effect of electron-donating groups (OH, NH₂) and the 3-directing effect of electron-withdrawing groups (NO₂) in electrophilic substitution of aromatic compounds

{Learners will not be expected to know further electron-donating or electron-withdrawing groups; relevant additional data will be supplied in examinations.}

(l) the prediction of substitution products of aromatic compounds by directing effects and the importance to organic synthesis

We saw with Phenols that Electron donating groups (which activate the ring) direct the electrophile towards 2 and 4.

2 is likely to be around twice as common as 4 because there are two equivalent Carbon atoms in the 2 position (2 and 6) but only one Carbon 4.

The reason for this is not examinable at A level, though there are plenty of internet sites that will explain it to you if you're interested.

The syllabus only mentions -NH₂ and -OH groups specifically so we have to assume that this is the only activating groups you are supposed to recall (this is a new addition to the syllabus so past papers aren't much guide).

You could reasonably expect a question that told you that Chloro/Bromo groups (or some other group) has the same directing effect as an -OH/-NH₂ group

It won't come as a surprise to learn that electron withdrawing groups (which deactivate the ring) direct electrophiles to position 3.

The only example that you're expected to recall is -NO₂ group.

Because the NO₂ group in Nitrobenzene is deactivating the ring we would still have to use Conc. Sulphuric/Conc Nitric mixture to achieve the second nitration - almost all of which will form 1,3-dinitrobenzene