The present disclosure relates to an integrated process for carboxylating and oxidizing an aromatic hydrocarbon substituted with at least one alkyl group. The process comprises the sub-steps of: carboxylating the aromatic hydrocarbon substituted with at least one alkyl group using carbon dioxide and at least one catalyst represented by formula I, (AxBy), optionally, in at least one liquid medium to generate a reaction mass comprising at least one oxidizing agent represented by a formula II (HxBy), and a carboxylated product substituted with at least one alkyl group; and (b) in-situ reacting the carboxylated product substituted with at least one alkyl group with the oxidizing agent represented by a formula II formed during sub-step of carboxylation to obtain oxidized product.