Process for Pd-catalyzed hydroxycarbonylation of diisobutene: effect of solvent
A process for Pd-catalyzed hydroxycarbonylation of diisobutene in an acetic acid solvent in the presence of a ligand having the following structure: In contrast to reaction solvents such as formic acid or 3,5,5 hexanoic acid the conversion rates were improved and greater than 90% at a reaction temperature of 120° C. and CO pressure of 40 bar.
1. A process comprising:
a) adding diisobutene, forming a reaction mixture,
b) adding of a compound comprising Pd, wherein the Pd is capable of forming a complex,
c) adding the ligand L1:
d) adding acetic acid, as a solvent for the reaction mixture,
e) feeding in CO,
f) 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 step b) is 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 ,
further comprises g) adding p-toluenesulfonic acid.
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 f).
5. The process according to claim 1 ,
wherein the CO is fed in in process step e) such that the reaction proceeds under a CO pressure in the range from 20 bar to 60 bar.