The role of dimethylcarbonate in the replacement of hazardous chemicals

In the frame of green chemistry, devising safer processes and products, phosgene substitution looks to be of great importance. Dimethylcarbonate (DMC), a non-toxic and environmentally benign chemical, represents a viable actual or potential phosgene substitute. Exploiting CuCl catalytic properties, EniChem developed on industrial scale the first non-phosgene DMC production process, based on one-step oxy-carbonylation of CH3OH. A commercially established process for the melt polymerization production of aromatic polycarbonates, making use of DMC and diphenylcarbonate (DPC) as intermediates, avoids at the same time the use of phosgene as a reactant, of methylene chloride as a solvent and the co-production of NaCl. Development of a non-phosgene production of isocyanates, taking place through thermolysis of the corresponding carbamate, produced from amine-carbonate reaction, is under way. (C) 2000 Academie des sciences / Editions scientifiques et medicales Elsevier SAS.