Dimethyl carbonate (DMC) is actually recognized as an environmentally benign chemical because of its negligible ecotoxicity and low bioaccumulation and persistence. The diffusion of DMC as safe chemical necessarily implies a clean and safe route for its production, such as the base-catalyzed transesterification reaction with methanol of alkylene carbonates. Until now few bases were reported to be effective as heterogeneous catalysts under mild conditions (low temperature and atmospheric pressure). Therefore inorganic salts, namely, Na3PO4 and Na2CO3, were selected because of their basic properties and their negligible ecotoxicity. Using Na3PO4 as catalyst, the equilibrium yield for the reaction ethylene carbonate → DMC is reached in about 1 h at atmospheric pressure and at a temperature above 50 °C, while in the case of the propylene carbonate → DMC reaction, the equilibrium yield is difficult to reach, because the kinetics of this reaction are 5 times slower than those of the EC → DMC reaction. Both reac...