Allyl acetate hydroformylation process
A process for the production of 4-acetoxybutyraldehyde is described. The process comprises reacting allyl acetate with a mixture of carbon monoxide and hydrogen in the presence of a solvent and a catalyst comprising a rhodium complex and a diphosphine. The diphoshine is a substituted or unsubstituted 2,2′-bis(dihydrocarbylphosphino)diphenyl ether. The process gives a high ratio of 4-acetoxybutyraldehyde:3-acetoxy-2-methylpropionaldehyde.
1. A process to produce 4-acetoxybutyraldehyde comprising reacting allyl acetate with carbon monoxide and hydrogen in the presence of a solvent and a catalyst comprising a rhodium complex and a substituted or unsubstituted 2,2′-bis(dihydrocarbylphosphino)diphenyl ether.
2. The process of claim 1 wherein the 2,2′-bis(dihydrocarbylphosphino)diphenyl ether is 2,2′-bis(diphenylphosphino)diphenyl ether.
3. The process of claim 1 wherein the 2,2′-bis(dihydrocarbylphosphino)diphenyl ether is a substituted or unsubstituted 4,5-bis(dihydrocarbylphosphino)xanthene.
4. The process of claim 3 wherein the 4,5-bis(dihydrocarbylphosphino)xanthene is 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene.
5. The process of claim 3 wherein the 4,5-bis(dihydrocarbylphosphino)xanthene is a 2,7-dialkyl-9,9-dimethyl-4,5-bis(diarylphosphino)xanthene.
6. The process of claim 5 wherein the 2,7-dialkyl-9,9-dimethyl-4,5-bis(diarylphosphino)xanthene is 2,7-di-tert-butyl-9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene.
7. 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.
8. The process of claim 1 wherein the solvent is selected from the group consisting of toluene, cyclohexane, methyl t-butyl ether, and mixtures thereof.
9. The process of claim 1 wherein the rhodium complex comprises rhodium and ligands selected from the group consisting of hydride, carbonyl, trialkyl phosphines, triaryl phosphines, cyclopentadienyls, 2,4-alkanedionates, and mixtures thereof.
10. The process of claim 1 wherein the catalyst further comprises a monophosphine compound.
11. The process of claim 1 further comprising converting at least a portion of the 4-acetoxybutyraldehyde to produce 1,4-butanediol.
12. The process of claim 1 further comprising converting at least a portion of the 4-acetoxybutyraldehyde to produce tetrahydrofuran.