Claims
- 1. A process for preparing aliphatic carboxylic acids having 4 to 11 carbon atoms by oxidation of the corresponding aldehydes with oxygen or oxygen-containing gas mixtures at 20 to 100° C., wherein the oxidation of the purified aldehydes takes place in the presence of 0.1 to 5.0 ppm by weight of a metal selected from the group consisting of vanadium, chromium, molybdenum, iron, cobalt, nickel, ruthenium, rhodium, palladium or copper or the corresponding amount of a compound of such a metal or mixtures of such metals and/or metal compounds, based on the aldehyde employed, with the proviso that the addition of polydentate ligands containing nitrogenous heterocycles shall be excluded.
- 2. The process of claim 1, wherein the oxidation of the aldehydes takes place in the presence of from 0.2 to 3 ppm of the metal or the corresponding amount of a compound of such a metal or mixtures of such metals and/or metal compounds, based on the aldehyde employed.
- 3. The process of claim 1, wherein the metal compounds are selected from the group consisting of carboxylates, acetylacetonates and carbonyl compounds.
- 4. The process of claim 3, wherein the metal carboxylates are salts of the carboxylic acids produced as the result of the oxidation of the aldehydes employed.
- 5. The process of claim 1, wherein the oxidation is carried out at temperatures in the range from 20 to 80° C.
- 6. The process of claim 1, wherein the oxidation is carried out under pressures in a range from atmospheric pressure to 1.0 Mpa.
- 7. The process of claim 1, wherein the oxygen-containing gas mixtures have a content of up to 90% by volume of inert gases.
- 8. The process of claim 2 wherein the amount of metal is 0.5 to 2 ppm.
- 9. The process of claim 1 wherein the metal is selected from the group consisting of chromium, iron, nickel and rhodium.
- 10. The process of claim 5 wherein the temperature is 40 to 80° C.
- 11. The process of claim 6, wherein the pressure is atmospheric pressure up to 0.8 Mpa.
- 12. The process of claim 7, wherein the gas mixture contains 30 to 80% by volume of inert gases.
Priority Claims (1)
Number |
Date |
Country |
Kind |
100 10 771 |
Mar 2000 |
DE |
|
Parent Case Info
This application is a 371 of PCT/EP01/01943 filed Feb. 21, 2001.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/EP01/01943 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO01/66504 |
9/13/2001 |
WO |
A |
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
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0682000 |
Nov 1995 |
EP |
706009 |
Mar 1954 |
GB |
1103885 |
Feb 1968 |
GB |
1565716 |
Apr 1980 |
GB |