Process for the preparation of monocarboxylic anhydrides

摘要

In the process for the preparation of monocarboxylic anhydrides of the general formula (RCO)2O by reacting a carboxylic ester or dialkyl ether of the general formulae RCOOR or ROR, where R is in each case the same alkyl radical having 1-4 C atoms, with carbon monoxide in the gas phase in the presence of iodine or bromine or compounds thereof as reaction promoter and in the presence of a supported catalyst containing noble-metal compounds of Group VIII of the Periodic Table at temperatures from 130 to 400 DEG C and pressures from 1 to 150 bar, the support material in the supported catalyst includes a noble-metal chelate compound formed from the noble-metal compound and a chelating agent having organonitrogen, organophosphorus, organoarsenic or organosulphur groups.