In converting benzene into phenol, Fenton's reagent can be used. In order to transform barbituric acid into alloxan, this reagent can also be used. The Fenton reagent is also useful in the hydroxylation of arenes. The Haber-Weiss reaction, which is a called reaction producing hydroxyl radicals from superoxide and hydrogen peroxide, is based on the first stage of Fenton's reaction (which requires the oxidation of ferrous ions with hydrogen peroxide).In organic synthesis reactions, Fenton's reagent may also be used. For instance, with the aid of Fenton's reagent, the hydroxylation of arenes through a free radical substitution mechanism can be achieved. By using Fenton's reagent, benzene can be converted into phenol. The Fenton reaction can also be used to oxidize alloxan into barbituric acid. The coupling reactions of alkanes are another major application of Fenton's reaction.