Process for preparing decanecarboxylic acids
View Patent ↗The invention relates to a process for preparing a mixture of isomeric decane-carboxylic acids, which comprises the following steps: a) hydroformylation of a hydrocarbon mixture containing linear C4-olefins using a rhodium-containing catalyst system; b) aldol condensation of a mixture of aliphatic C5-aldehydes obtained from step a); c) selective hydrogenation of the mixture of unsaturated C10-aldehydes from step b) to aliphatic C10-aldehydes; d) uncatalysed oxidation of the mixture of aliphatic C10-aldehydes from step c) to give a mixture having a proportion of at least 70% by mass of 2-propylheptanoic acid, based on the total content of isomeric decanecarboxylic acids.
1. A process for preparing a mixture of isomeric decanecarboxylic acids, the process comprising:
a) hydroformylating a hydrocarbon mixture comprising linear C4-olefins, in the presence of a rhodium-containing catalyst system, to obtain a mixture of aliphatic C5-aldehydes;
b) condensing, by aldol condensation, the mixture of aliphatic C5-aldehydes, to obtain a mixture of unsaturated C 10-aldehydes;
c) hydrogenating, by selective hydrogenation, the mixture of unsaturated C10-aldehydes, to obtain a mixture of aliphatic C10-aldehydes;
d) oxidizing, by uncatalysed oxidation, the mixture of aliphatic C10-aldehydes to obtain a mixture of isomeric decanecarboxylic acids, said mixture of acids comprising at least 70% by mass of 2-propylheptanoic acid, based on a total content of isomeric decanecarboxylic acids.
2. The process of claim 1 , wherein the hydrocarbon mixture comprises up to 5% by mass of isobutene, based on a fraction of the linear C4-olefins.
3. The process of claim 1 , wherein the oxidizing d) is carried out in a temperature range from 25 to 35° C.
4. The process of claim 1 , wherein the oxidizing d) is carried out at a pressure in the range from 0.1 to 1 MPa.
5. The process of claim 1 , wherein the oxidizing d) is carried out at a pressure in the range from 0.1 to 0.5 MPa.
6. The process of claim 2 , wherein the oxidizing d) is carried out in a temperature range from 25 to 35° C.
7. The process of claim 2 , wherein the oxidizing d) is carried out at a pressure in the range from 0.1 to 1 MPa.
8. The process of claim 3 , wherein the oxidizing d) is carried out at a pressure in the range from 0.1 to 1 MPa.
9. The process of claim 2 , wherein the oxidizing d) is carried out at pressure in the range from 0.1 to 0.5 MPa.
10. The process of claim 3 , wherein the oxidizing n d) is carried out at pressure in the range from 0.1 to 0.5 MPa.
11. The process of claim 4 , wherein the oxidizing d) is carried out at pressure in the range from 0.1 to 0.5 MPa.