When disubstituted benzenes undergo electrophilic substitution, the product distribution depends on the directing effect of both substituents. When the directing effects of both substituentsreinforce each other,a single product is obtained. For example, bromination of p-nitrotoluene occurs ortho to the methyl group and meta to the nitro group, which isthe same position, resulting in a single product. However, if the directing effects of the two groups oppose each other, the more strongly activating group directs the substituentposition. For instance, in the nitration of p-methylphenol, the stronger activator—the hydroxyl group—directs the substitution ortho to it. Substituents with similaractivating properties furnish a mixture of products. The steric effect is also instrumental in determining product distribution. For instance, nitration of p-tert-butyltoluene occurs at the less hindered position—ortho to the methyl group. Similarly,substitution does not usuallyoccur between two groups in a meta-disubstituted ring.