Method for preparation of DINITROTOLUENES

The present invention relates to a preparation process of dinitrotoluene by reacting mononitrotoluene and nitric acid in the liquid phase. The method is characterized in that the reaction is conducted in the presence of an acid and inorganic solid comprising at least one component selected from the group consisting of orthophosphoric acid, pyrophosphoric acid, metaphosphoric acid, metal dihydrogen phosphate, metal hydrogen phosphates, metal pyrophosphates and metal orthophosphates derived from metals capable of forming cations carriers 1 to 5 positive charges.