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US 4,788,333 AGranted
Hydrocarboxylation of unsaturated carboxylic acids to linear dicarboxylic acids
AssigneeE. I. Du Pont de Nemours and Company
InventorPatrick M. Burke
Life of this patent
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Abstract
The preparation of linear dicarboxylic acids, e.g., adipic acid, by hydrocarboxylating unsaturated monocarboxylic acids, e.g., 3-pentenoic acid, with carbon monoxide and water in the presence of a rhodium-containing catalyst, an iodide promoter and certain inert halocarbon solvents, e.g., methylene chloride.
Claims8
A process for the preparation of linear saturated dicarboxylic acids which comprises contacting an unsaturated monocarboxylic acid having the formula
- wherein R is selected from the class consisting of hydrogen, methyl and ethyl, n is 0-8 with carbon monoxide and water in the presence of a rhodium-containing catalyst, an iodide compound and a hydrolysis resistant saturated halocarbon solvent, except fluorocarbon, and mixtures thereof having 1-2 carbon atoms and when the solvent has two carbon atoms not more than two halogen atoms are attached to each carbon atom, at a temperature in the range of 100.degree.-240.degree. C. and a pressure in the range of 14-240 atmospheres while maintaining the concentration of water less than 4.3% by weight based upon the weight of the solvent.
Dependencies are inferred from the claim text.