Patent ID: 6740768
Filing Date: 2004-05-25
Classification: C07C,Y02P

Abstract:
Process for the preparation of symmetrical and asymmetrical carbonates of the general formula Iin which R and Râ€² are the same or different and signify a straight-chained or branched alkyl group with 1 to 10 C-atoms, a benzyl group unsubstituted or substituted with up to three C1-C4-alkyl groups, C1-C4-alkoxy groups, halogen atoms, with a cyano group, a nitro group, a trifluoromethyl group or an alkoxycarbonyl group with up to 4 C-atoms, characterised in that one converts alcohols of the general formula II and alkyl or aryl halides of the general formula IIIRâ€”OHâ€ƒâ€ƒII Râ€²â€”HALâ€ƒâ€ƒIII in which R and Râ€² possess the above-given meaning and HAL stands for chlorine, bromine or iodine, by reaction with carbon dioxide and caesium carbonate in a dipolar aprotic solvent into organic carbonates of the general formula I.