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US 5,476,959 AGranted
Process for the preparation of dialkyl carbonates
AssigneeBayer Aktiengesellschaft
InventorsKonrad Hable, Alexander Klausener, Zoltan Kricsfalussy, Heinz Landscheidt, Erich Wolters, Eberhard Zirngiebl
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Abstract
Dialkyl carbonates can be prepared by reacting carbon monoxide with alkyl nitrites in a continuous gas phase reaction in the presence of a heterogeneous platinum metal catalyst, the activity of this catalyst being maintained by the addition of small amounts of halogen. The dialkyl carbonates are thus formed with almost quantitative selectivity and no deactivation of the catalyst occurs.
Claims15
A process for the preparation of a dialkyl carbonate of the formula
- O.dbd.C(OR).sub.2,
- wherein
- R represents linear of branched C.sub.1 -C.sub.4 -alkyl,
- by reacting carbon monoxide (CO) with an alkyl nitrite of the formula
- RONO,
- wherein
- R is as defined,
- in the presence of an inert gas, in the presence of the corresponding alcohol and in the presence or absence of NO, on a supported platinum metal catalyst, at elevated temperature in a continuous gas phase reaction, wherein the reaction is carried out at a volume ratio of alkyl nitrite:CO=0.1 to 10:1, a pressure of 0.5 to 10 bar, and a temperature of 50.degree. to 170.degree. C., element halogen being added batchwise or continuously.
5 more elements
Dependencies are inferred from the claim text.