Hydroformylation process
View Patent ↗A process for the production of 4-hydroxybutyraldehyde is described. The process comprises reacting allyl alcohol with a mixture of carbon monoxide and hydrogen in the presence of a solvent and a catalyst system comprising a rhodium complex and a substituted or unsubstituted 4,5-bis(di-n-alkylphosphino)xanthene. The process gives high yield of 4-hydroxybutyraldehyde compared to 3-hydroxy-2-methylpropionaldehyde.
1. A process to produce 4-hydroxybutyraldehyde comprising reacting allyl alcohol with carbon monoxide and hydrogen in the presence of a solvent and a catalyst system comprising a rhodium complex and a substituted or unsubstituted 4,5-bis(di-n-alkylphosphino)xanthene.
2. The process of claim 1 wherein the 4,5-bis(di-n-alkylphosphino)xanthene is 9,9-dimethyl-4,5-bis(dimethylphosphino)xanthene.
3. The process of claim 1 wherein the 4,5-bis(di-n-alkylphosphino)xanthene is 9,9-dimethyl-4,5-bis(diethylphosphino)xanthene.
4. The process of claim 1 wherein the solvent is selected from the group consisting of C 5 -C 20 aliphatic hydrocarbons, C 6 -C 12 aromatic hydrocarbons, ethers, alcohols, and mixtures thereof.
5. The process of claim 1 wherein the solvent is selected from the group consisting of toluene, cyclohexane, methyl t-butyl ether, and mixtures thereof.
6. The process of claim 1 wherein the rhodium complex comprises rhodium and ligands selected from the group consisting of hydride, carbonyl, trialkyl or triaryl phosphines, diphosphines, cyclopentadienyls, 2,4-alkanedionates, and mixtures thereof.
7. The process of claim 1 wherein the reaction is performed at a temperature within the range of about 45° C. to about 85° C. and a pressure within the range of about 30 to about 400 psig.
8. The process of claim 1 wherein the catalyst system further comprises a monophosphine compound.
9. The process of claim 8 wherein the monophosphine compound is triphenylphosphine.
10. The process of claim 1 further comprising hydrogenating the 4-hydroxybutyraldehyde in the presence of a hydrogenation catalyst to form 1,4-butanediol.
11. The process of claim 10 wherein the hydrogenation catalyst is a nickel catalyst.
12. A catalyst system comprising a rhodium complex and a substituted or unsubstituted 4,5-bis(di-n-alkylphosphino)xanthene.
13. The catalyst system of claim 12 wherein the 4,5-bis(di-n-alkylphosphino)xanthene is 9,9-dimethyl-4,5-bis(dimethylphosphino)xanthene.
14. The catalyst system of claim 12 wherein the 4,5-bis(di-n-alkylphosphino)xanthene is 9,9-dimethyl-4,5-bis(diethylphosphino)xanthene.
15. The catalyst system of claim 12 wherein the rhodium complex comprises rhodium and ligands selected from the group consisting of hydride, carbonyl, trialkyl or triaryl phosphines, diphosphines, cyclopentadienyls, 2,4-alkanedionates, and mixtures thereof.