European Patent Office - EP 0445891 B1

EP 0 445 891 B1A dimethyl carbonate yield of 2.88 g (32 mmoles) is determined.EXAMPLE 355 60 g of methanol, 12.2 g (51 moles) of sodium peroxydisulphate and 1 .68 g (1 0 mmoles) of hydrobromicacid in 48 wt% aqueous solution are introduced into a 250 ml pressure vessel lined internally with Teflonand fitted with a mechanical stirrer and heat transfer means. Carbon monoxide is fed into the pressure vesselto a pressure of 3 MPa (30 kg/cm2). It is heated to 110°C under stirring for 105 minutes. It is then cooled toambient temperature, the gas vented and the liquid subjected to gaschromatography analysis.10 A dimethyl carbonate yield of 1 .35 g (1 5 mmoles) is determined.EXAMPLE 3670 g of methanol, 8.9 g (50 moles) of N-bromosuccinimide and 1.68 g (10 mmoles) of hydrobromic acid in15 48 wt% aqueous solution are introduced into a 250 ml pressure vessel lined internally with Teflon and fittedwith a mechanical stirrer and heat transfer means. Carbon monoxide is fed into the pressure vessel to a pressureof 3 MPa (30 kg/cm2). It is heated to 70°C under stirring for 120 minutes. It is then cooled to ambient temperature,the gas vented and the liquid subjected to gaschromatography analysis.A dimethyl carbonate yield of 4.23 g (47 mmoles) is determined.20Claims251. A process for preparing an organic carbonate having the general formula:OR35or a cyclic organic carbonate having the general formula:40(II)45wherein: R is a CrC10 linear or branched alkyl, or a C5-C6 cycloalkyl, and R' is a C2-C5 linear or branchedalkylene, by reacting an alcohol R-OH, or a diol HO-R'-OH, respectively, with carbon monoxide at a tem-50 perature of from 25°C to 200°C, the cabon monoxide pressure being of from 0,1 MPa to 1 0 MPa (1 kg/cm2to 100 kg/cm2), characterized in that said reaction is carried out in the presence of a catalyst consistingof a halogen selected from chlorine, bromine and iodine, or in the presence of a catalyst consisting of saidhalogen and/or a halide ion selected from the chloride, the bromide and the iodide ion and an oxidizingagent capable of oxidizing said halide ion to its corresponding halogen, with the proviso that said halide55 ion is other than an ion derived from the halides of a metal of the platinum group or of copper.2. A process as claimed in claim 1 , characterised in that R-OH is chosen from methanol, ethanol, n-propanol,iso-propanol, n-butanol, iso-butanol, 2-ethylhexanol and cyclohexanol, and is preferably methanol; and12