Preparation of carboxylic-acid anhydrides by carbonylation.

摘要

1. Process for the preparation of anhydrides of carboxylic acids by carbonylation of carboxylic esters of formula RCOOR in which R denotes an alkyl radical containing up to 12 carbon atoms or a radical C6 H5 -Cx H2x -, x being an integer from 1 to 6 included, in a liquid phase containing a solvent chosen from the amides of carboxylic acids, in a substantially anhydrous medium, in the presence of an effective quantity of nickel and a halogen-based promoter, characterised in that the reaction is carried out in the presence of at least one alkyl iodide or acyl iodide and at least one co-catalyst chosen from the ionic compounds of the alkali metals and alkaline earth metals.