Synthesis of caprolactam from lysine
View Patent ↗In various embodiments, the present invention can involve a method of synthesizing α-amino-ε-caprolactam. The method can comprise heating a salt of L-lysine in a solvent comprising an alcohol. In other embodiments, the present invention can involve methods for synthesizing ε-caprolactam. The methods can comprise heating a salt of L-lysine in a solvent comprising an alcohol and deaminating the reaction product. In various embodiments, the invention can include methods of converting biomass into nylon 6. The methods can comprise heating L-lysine in a solvent comprising an alcohol to produce α-amino-ε-caprolactam, deaminating to produce ε-caprolactam and polymerizing into nylon 6, wherein the L-lysine is derived from the biomass. In other embodiments, the present invention can include methods of making nylon 6. The methods can comprise synthesizing ε-caprolactam and then polymerizing, wherein the ε-caprolactam is derived from L-lysine.
1. A process for synthesizing α-amino-ε-caprolactam, the process comprising heating to reflux a salt of lysine in a solvent comprising an alcohol, without the presence of a catalyst, at a temperature of about 99° C. to about 201° C., to produce α-amino-ε-caprolactam.
2. A process according to Claim 1 further comprising purifying the α-amino-ε-caprolactam.
3. A process according to Claim 1 further comprising crystallizing the α-amino-ε-caprolactam.
4. A process according to Claim 1 , wherein the lysine is L-lysine.
5. A process according to Claim 1 , wherein the alcohol has from 2 to 6 carbons.
6. A process according to Claim 5 , wherein the alcohol comprises a diol.
7. A process according to Claim 5 , wherein the alcohol comprises a triol.
8. A process according to Claim 5 , wherein the alcohol comprises a glycol.
9. A process according to Claim 5 , wherein the alcohol is from the group consisting of ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1,2-propanediol, and mixtures thereof.
10. A process according to Claim 9 , wherein the alcohol is butanol or 1,2-propanediol.
11. A process according to Claim 1 , wherein the heating is below the temperature of polymerization of caprolactam.
12. A process according to Claim 1 , wherein the heating allows the azeotropic removal of water.
13. A process according to Claim 1 , wherein the heating is at a temperature of from about 99° C. to about 187° C.
14. A process for the synthesis of ε-caprolactam, the process comprising:
(A) heating a salt of lysine in a solvent comprising an alcohol, at a temperature of about 99° C. to about 201° C., to produce α-amino-ε-caprolactam; and
(B) deaminating α-amino-ε-caprolactam produced in (A) by a method comprising contacting it at least once with a deamination reagent or catalyst at a temperature below the freezing point of water, to produce ε-caprolactam.
15. A process according to Claim 14 , wherein the yield of ε-caprolactam is greater than about 70%.
16. A process according to Claim 14 , wherein the lysine is L-lysine.
17. A process according to Claim 14 , wherein the temperature in (B) is from about -5° C. to about -20° C.
18. A process according to Claim 14 , wherein the process further comprises (C) washing ε-caprolactam, produced by the deaminating (B), using a solvent wash.
19. A process according to Claim 18 , wherein the washing solvent comprises a mixture of water and alcohol.
20. A process according to Claim 18 , wherein the washing solvent is water.
21. A process according to Claim 14 further comprising purifying the ε-caprolactam.
22. A process according to Claim 21 , wherein the purifying is by sublimation.
23. A process according to Claim 14 , wherein the heating (A) comprises heating in the presence of a catalyst.
24. A process according to Claim 23 , wherein the catalyst is A 2 O 3 .
25. A process according to Claim 14 , wherein the alcohol has from 2 to 6 carbons.
26. A process according to Claim 25 , wherein the alcohol is from the group consisting of ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1,2-propanediol, and mixtures thereof.
27. A process according to Claim 14 , wherein the alcohol is butanol or 1,2-propanediol.
28. A process according to Claim 14 , wherein the heating is below the temperature of polymerization of caprolactam.
29. A process according to Claim 14 , wherein the heating allows the azeotropic removal of water.
30. A process according to Claim 14 , wherein the heating is accomplished by reflux.
31. A process according to Claim 14 , wherein the deaminating (B) employs potassium hydroxide and hydroxylamine-O-sulphonic acid.
32. A process for synthesizing α-amino-ε-caprolactam comprising:
heating a mixture comprising a salt of lysine in a solvent comprising an alcohol, without the presence of a catalyst at a temperature of from about 99° C. to about 201° C.; and
removing water from the mixture during the heating step.
33. A process according to Claim 32 , wherein the heating step includes a temperature of about 99° C. to 187° C.
34. A process according to Claim 32 , wherein the alcohol comprises a diol or triol.
35. A process according to Claim 32 , wherein the step of removing water from the mixture includes azeotropic removal of water.
36. A process according to Claim 32 , wherein the alcohol is butanol or 1,2-propanediol.