PRODUCTION OF MONOCARBOXYLIC ANHYDRIDE

In a process for the preparation of monocarboxylic acid anhydrides of the general formula (RCO)2O by reaction of a carboxylic acid ester or dialkyl ether of the general formula RCOOR or ROR, in which R in each case denotes the same alkyl radical having 1 to 4 C atoms, with carbon monoxide in the gas phase in the presence of iodine or bromine or compounds thereof as reaction promoters and in the presence of a supported catalyst at temperatures from 130 to 400 DEG C and pressures from 1 to 150 bar, where, in the supported catalyst, an organosilicon compound is bonded to a support material as a polyfunctional adhesion promoter on the one hand and to a noble metal compound of group VIII of the Periodic Table on the other hand, a chelate-forming organosilicon compound of the general formula is employed as the polyfunctional adhesion promoter, in which X = -Cl, -Br or -OR ; Y = -NR@, a nitrogen-containing aryl radical, -PR@, AsR@, -SR or -SH; Z = zero, arylene or phenylene (optionally ortho-, meta- or para-substituted> R = C1 to C5-alkyl; R = C1 to C5-alkyl or -C6H5; R = -H, C1 to C3-alkyl; R = C1 to C6-alkyl, C5 or C6-cycloalkyl or -C6H5 or -CH2C6H5, which are optionally substituted by halogen, methoxy, ethoxy or C1 to C3-alkyl groups; n = 0 or 1 or 2; and m = 2 to 6, preferably 2 to 4.