Production of caprolactam from carbohydrate-containing materials
The present invention generally relates to processes for the conversion of glucose to caprolactam employing chemocatalytic oxidation and reduction reactions. The present invention also includes processes for the conversion of glucose to caprolactam via amido polyhydroxy acid products and amidocaproic acid or derivatives thereof. The present invention also includes processes that catalytically oxidize an amidopolyol to amidopolyhydroxy acid or derivatives thereof, and processes that catalytically hydrodeoxygenate amino or amido polyhydroxy acid or derivatives thereof to an amino or amidocaproic acid product. The amino or amidocaproic acid product may then be converted to caprolactam. The present invention also includes products produced by such processes and products producable from such products.
1. A process for preparing an amino or amidocaproic acid product, the process comprising:
reacting, in the presence of a hydrodeoxygenation catalyst comprising at least a first metal selected from the group consisting of palladium, iridium, and rhodium and a halogen source, an amino or amido polyhydroxy acid substrate and hydrogen to convert at least a portion of the amino or amido polyhydroxy acid substrate to the amino or amidocaproic acid product, wherein the amino or amido polyhydroxy acid substrate is a compound of formula IIa and the amino or amidocaproic acid product is a compound of formula III:
wherein each X is independently hydroxyl, oxo, halo, or acyloxy;
wherein R 1 is acyl, substituted acyl, aroyl, substituted aroyl, or hydrogen; and
wherein R 2 is a salt-forming ion, hydrogen, or a lactone thereof.
2. The process of claim 1 , wherein each X is hydroxyl.
3. The process of claim 1 or 2 , wherein R 1 is acyl.
4. The process of claim 1 or 2 , wherein R 1 is acetyl.
5. The process of claim 1 or 2 , wherein the amino or amido polyhydroxy acid substrate is 6-amino-6-deoxygulonic acid or 6-N-acetamino-6-deoxygulonic acid.
6. The process of claim 1 or 2 , wherein the amino or amido polyhydroxy acid substrate is 6-N-acetamido-6-deoxygulonic acid.
7. The process of claim 1 or 2 , wherein the hydrodeoxygenation catalyst comprises a heterogeneous catalyst.
8. The process of claim 7 , wherein the hydrodeoxygenation catalyst comprises a second metal selected from the group consisting of Ru, Rh, Pd, Pt, Ir, and Au, provided the second metal is different than the first metal.
9. The process of claim 8 , wherein the hydrodeoxygenation catalyst comprises palladium and rhodium.
10. The process of claim 1 or 2 , wherein the hydrodeoxygenation catalyst is a supported catalyst and the support is selected from the group consisting of silicas and zirconias.
11. The process of claim 1 or 2 , wherein the halogen source is selected from the group consisting of ionic, atomic and molecular forms of iodine and bromine.
12. The process of claim 1 or 2 , wherein the halogen source is hydrogen iodide or hydrogen bromide.
13. The process of claim 12 , wherein the halogen source is hydrogen iodide.
14. The process of claim 1 or 2 , wherein the molar ratio of halogen source to amino or amido polyhydroxy acid substrate is at least about 1.
15. The process of claim 1 or 2 , wherein the reaction is maintained at a temperature of at least about 80° C.
16. The process of claim 1 or 2 , wherein the reaction is maintained at a temperature of about 100° C. to about 200° C.
17. The process of claim 1 or 2 , wherein the reaction is maintained at a temperature of about 120 to about 180° C.
18. The process of claim 1 or 2 , wherein the reaction is conducted under a partial pressure of hydrogen in the range of from about 15 psia (104 kPa) to about 2000 psia (13790 kPa).
19. The process of claim 1 or 2 , wherein the reaction is conducted under a partial pressure of hydrogen in the range of from about 300 psia (2069 kPa) to about 1500 psia (10342 kPa).
20. The process of claim 1 or 2 , wherein at least a portion of the amino or amido polyhydroxy acid substrate is derived from glucose.
21. The process of claim 20 , wherein at least a portion of the glucose is derived from a carbohydrate source.
22. The process of claim 1 or 2 , wherein the reaction further comprises a weak carboxylic acid, and wherein at least a portion of the amino or amido polyhydroxy acid substrate is solubilized with the weak carboxylic acid.
23. The process of claim 22 , wherein the pKa of the weak carboxylic acid is at least about 4.5.
24. The process of claim 22 , wherein the weak carboxylic acid is acetic acid.
25. A process for preparing an amidocaproic acid compound from glucose, the process comprising:
converting glucose to a cyclic amido polyol compound of formula IV:
wherein R 3 is acyl, substituted acyl, aroyl, or substituted aroyl;
reacting, in the presence of an oxidation catalyst, at least a portion of the cyclic amido polyol compound and an oxidant to convert at least a portion of the cyclic amido polyol compound to a cyclic polyhydroxy acid compound of formula V:
wherein R 3 is as defined above and R 4 is a salt-forming ion or hydrogen; and
reacting, in the presence of a hydrodeoxygenation catalyst comprising at least a first metal selected from the group consisting of palladium, iridium, and rhodium and a halogen source, at least a portion of the cyclic polyhydroxy acid compound and hydrogen to convert at least a portion of the cyclic polyhydroxy acid compound to an amidocaproic acid compound of formula VI:
wherein R 3 and R 4 are as defined above.
26. A process for preparing an amidocaproic acid product, the process comprising:
converting an amidopolyol substrate to an amido polyhydroxy acid substrate,
wherein the amidopolyol substrate is a compound of formula I:
wherein R 1 is acyl, substituted acyl, aroyl or substituted aroyl; and
wherein the amido polyhydroxy acid substrate is a compound of formula IIa:
wherein X is hydroxyl,
wherein R 1 is as defined above, and
wherein R 2 is a salt-forming ion, hydrogen, or a lactone thereof; and
reacting, in the presence of a hydrodeoxgenation catalyst comprising at least a first metal selected from the group consisting of palladium, iridium, and rhodium and a halogen source, the amido polyhydroxy acid substrate and hydrogen to convert at least a portion of the amido polyhydroxy acid substrate to an amidocaproic acid product, wherein the amidocaproic acid product is a compound of formula III:
wherein X, R 1 , and R 2 are as defined above.
27. The process of claim 26 , wherein the amidopolyol substrate is converted to the amido polyhydroxy acid substrate by reacting the amidopolyol substrate with oxygen in the presence of an oxidation catalyst.
28. The process of claim 27 , wherein the oxidation catalyst comprises a heterogeneous catalyst.
29. The process of claim 28 , wherein the oxidation catalyst comprises a metal selected from the group consisting of palladium and platinum.
30. The process of claim 26 , wherein the amidopolyol substrate is 6-amido-6-deoxysorbitol or 6-N-acetamido-6-deoxysorbitol.