Process for Pd-catalyzed hydroxycarbonylation of diisobutene: sulfuric acid/ligand ratio

1. A process for preparing compound P1 comprising:

a) adding diisobutene to form a reaction mixture,

b) adding a compound comprising Pd to the reaction mixture, wherein the Pd is capable of forming a complex,

c) adding ligand L1 to the reaction mixture:

d) adding acetic acid to the reaction mixture,

e) adding sulfuric acid to the reaction mixture, wherein the sulfuric acid is in an amount which is at least an amount between 3.5 and 5 mol of sulfuric acid per mole of ligand L1,

f) feeding into the reaction mixture CO,

g) heating the reaction mixture such that the diisobutene is converted to the compound P1:

2. The process according to claim 1 ,

wherein the compound in process step b)

PdCl 2 , PdBr 2 , Pd(acac) 2 , Pd(dba) 2 (dba=dibenzylideneacetone), or PdCl 2 (CH 3 CN) 2 .

3. The process according to claim 1 ,

wherein the sulfuric acid is added in an amount which is in the range from 3.5 mol to 4.5 mol of sulfuric acid per mole of ligand L1.

4. The process according to claim 1 ,

wherein the reaction mixture is heated to a temperature in the range from 80° C. to 160° C. in process step g).

5. The process according to claim 1 ,

wherein the CO is fed in process step f) such that the reaction proceeds under a CO pressure in the range from 10 bar to 40 bar.