US 4,536,354 AGranted

Process for the preparation of carboxylic anhydrides

AssigneeShell Oil Company

InventorEit Drent

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Abstract

A process is disclosed for preparing carboxylic acid anhydrides by reacting certain esters or ethers with carbon monoxide in the presence of a nickel catalyst, a source of iodide and/or bromide and conventional promoters, which process is improved by the use as co-promoters of a compound selected from compounds of the formula ##STR1## in which X represents phosphorus, arsenic or antimony and Y represents oxygen, sulphur or selenium, and a and b are O or 1 and R.sup.5 represents hydrogen or an optionally substituted hydrocarbon group and R.sup.6 and R.sup.7 represent an optionally substituted hydrocarbon group; compounds wherein a and b are O and R.sup.6 and R.sup.7 form a heterocyclic group with X and R.sup.5 represents hydrogen or an optionally substituted hydrocarbon group; and complexes of compounds of formula I with any of a hydrocarbon iodide or bromide, an acyl iodide or bromide, or hydrogen iodide or hydrogen bromide.

Claims19

Dependent claims

Process for the preparation of a carboxylic anhydride by reacting under virtually water-free conditions an ester having the formula R.sup.1 COOCH.sub.2 R.sup.2 or an ether having the formula R.sup.3 OR.sup.4 in which R.sup.1, R.sup.3 and R.sup.4 represent hydrocarbon groups containing up to 20 carbon atoms and which may be substituted with halogen atoms, and R.sup.2 represents hydrogen or a hydrocarbon group containing up to 20 carbon atoms and which may be substituted with halogen atoms;

with carbonmonoxide in the presence of a nickel catalyst, an iodide and/or bromide source and at least one co-promoter, the improvement comprising that the reaction is carried out in the presence of:
(A) a compound having the formula ##STR4## in which X represents phosphorus, arsenic or antimony and Y oxygen, sulphur or selenium and a and b are 0 or 1 and R.sup.5 represents hydrogen or a hydrocarbon group containing up to 30 carbon atoms which may be substituted with halogen atoms and R.sup.6 and R.sup.7 represent a hydrocarbon group containing up to 30 carbon atoms which may bear substituent selected from the group consisting of halogen atoms, and a R.sup.9 R.sup.10 X.dbd.Y group wherein X and Y are defined above and R.sup.9 and R.sup.1O represent a hydrocarbon group containing up to 8 carbon atoms, or a and b are 0 and R.sup.6 and R.sup.7 together form a heterocyclic group with X, and R.sup.5 is as defined above;
or (B) in the presence of a complex of a compound having the formula I with a hydrocarbon iodide or bromide, an acyl iodide or bromde or HI or HBr.

Dependencies are inferred from the claim text.