In a process for oxidizing a hydrocarbon to a corresponding hydroperoxide, alcohol, ketone, carboxylic acid or dicarboxylic acid, the hydrocarbon is contacted with an oxygen- containing gas in the presence of a catalyst comprising a cyclic imide of the general formula (I), wherein each of R1 and R2 is independently selected from hydrocarbyl and substituted hydrocarbyl radicals having 1 to 20 carbon atoms, or from the groups SO3H, NH2, OH and NO2, or from the atoms H, F, Cl, Br and I provided that R1 and R2 can be linked to one another via a covalent bond; each of Q1 and Q2is independently selected from C, CH, N and CR3; each of X and Z is independently selected from C, S, CH2, N, P and an element of Group 4 of the Periodic Table; Y is O or OH; k is 0, 1, or 2; 1 is 0, 1, or 2; m is 1 to 3, and R3 can be any of the entities listed for R1. The contacting produces an effluent comprising an oxidized hydrocarbon product and unreacted imide catalyst of formula (I) and the effluent is treated with an aqueous solution of a base to produce an aqueous phase comprising at least part of the unreacted imide catalyst of formula (I) and an organic phase comprising oxidized hydrocarbon product. The organic phase can then be recovered.