Alkyl groups that are attached to benzene rings can be oxidized with potassium permanganate, KMnO4, or a combination of sodium dichromate, Na2Cr2O7, and H2SO4 to form carboxylic acids. This is a great way to form benzoic acid compounds.

We have seen previously that benzylic positions are quite reactive to free radical halogenation because the radicals that form are stabilized through resonance.