Synthesis of caprolactam from lysine

• US 20070149777A1
• Filed: 12/07/2006
• Published: 06/28/2007
• Est. Priority Date: 06/10/2004
• Status: Active Grant

• Current Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Original Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Inventors: Frost, John
• Granted Patent: US 7,399,855 B2
• Time in Patent Office: Days
• US Class Current: 540/527
• CPC Class Codes: C07D 201/08 from carboxylic acids or derivatives thereof, e.g. hydroxy carboxylic acids, lactones or nitriles
• CPC Class Codes: C07D 223/12 Nitrogen atoms not forming part of a nitro radical

Abstract

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.

Claims

1. A process for synthesizing α

-amino-ε

-caprolactam, the process comprising heating 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 ε

-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 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 accomplished by reflux.

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 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) removing an amine, 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 Al₂O₃.

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 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 hydroxyl-O-sulphonic acid as deamination catalyst.

32. A method for producing nylon 6, the method comprising:

(A) heating lysine in a solvent comprising an alcohol, at a temperature of about 99°

C. to about 201°

C., to produce α

-amino-ε

-caprolactam;

(B) deaminating α

-amino-ε

-caprolactam produced in (A) by a method comprising contacting it at least once with a deamination catalyst at a temperature below the freezing point of water, to produce ε

-caprolactam; and

(C) polymerizing ε

-caprolactam produced in (B) into nylon 6.

33. A method according to claim 32, wherein the lysine comprises L-lysine derived from biomass.

34. A method according to claim 33, wherein the L-lysine is derived by obtaining a sugar from the biomass and converting the sugar into L-lysine.

35. A method according to claim 34, wherein the converting comprises using a fermentation reaction to convert the sugar into L-lysine.

36. A method according to claim 35 further comprising recycling an amine, produced by deamination of α

-amino-ε

-caprolactam, into the fermentation reaction.

37. A method according to claim 33 further comprising creating lactic acid from the biomass.

38. A method according to claim 37 further comprising hydrogenating the lactic acid to produce 1,2-propanediol.

39. A method according to claim 38 further comprising using the 1,2-propanediol as the alcohol in the heating step (A).

40. A method according to claim 32, wherein the heating (A) comprises heating in the presence of a catalyst.

41. A method according to claim 32, wherein the alcohol used in the heating step (A) has from 2 to 6 carbons.

42. A method according to claim 41, wherein the alcohol comprises a diol.

43. A method according to claim 41, wherein the alcohol comprises a triol.

44. A method according to claim 41, wherein the alcohol comprises a glycol.

45. A method according to claim 41, wherein the alcohol is from the group consisting of ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1,2-propanediol, and mixtures thereof.

46. A method according to claim 45, wherein the alcohol is 1,2-propanediol.

47. A method according to claim 32, wherein the heating is below the temperature of polymerization of caprolactam.

48. A method according to claim 32, wherein the heating allows the azeotropic removal of water.

49. A method according to claim 32, wherein the heating is accomplished by reflux.