Methods of forming alpha, beta-unsaturated acids and esters

• US 20040110974A1
• Filed: 12/09/2002
• Published: 06/10/2004
• Est. Priority Date: 12/09/2002
• Status: Active Grant

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Werpy, Todd A., Holladay, Johnathan E., Lilga, Michael A.
• Granted Patent: US 6,992,209 B2
• Time in Patent Office: Days
• US Class Current: 554/161
• CPC Class Codes: C07C 51/377 by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups C07C51/36 - C07C51/373 take precedence
• CPC Class Codes: C07C 57/04 Acrylic acid; Methacrylic acid
• CPC Class Codes: C07C 67/08 by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
• CPC Class Codes: C07C 67/327 by elimination of functional groups containing oxygen only in singly bound form
• CPC Class Codes: C07C 69/003 Esters of saturated alcohols having the esterified hydroxy group bound to an acyclic carbon atom
• CPC Class Codes: C07C 69/14 of monohydroxylic compounds
• CPC Class Codes: C07C 69/54 Acrylic acid esters; Methacrylic acid esters
• CPC Class Codes: C07C 69/67 of saturated acids
• CPC Class Codes: Y02P 20/10 Process efficiency
• CPC Class Codes: Y02P 20/582 Recycling of unreacted starting or intermediate materials

Abstract

The invention includes a method of forming an alpha, beta-unsaturated compound. A carboxylic acid is mixed with an alpha-hydroxy acid or an alpha-hydroxy ester and is esterified to form an alpha-acyloxy derivative. The alpha-acyloxy derivative is transformed into an alpha, beta-unsaturated derivative. The invention additionally includes a process of forming an acrylate. Lactic acid or a lactic acid ester is reacted with a first portion of acetic acid in the presence of a first catalyst to produce the corresponding 2-acetoxy propionic acid or ester. A non-reacted portion of the acetic acid is recycled. The 2-acetoxy propionic acid or ester is transferred to a second vessel containing a second catalyst, and acetic acid is liberated from the 2-acetoxy propionic acid or ester to produce a corresponding acrylic acid or acrylate ester. The acid or ester is subsequently esterified by reaction with an alcohol to form a desired acrylate ester.

Claims

1. A method of forming an alpha, beta-unsaturated compound comprising:

mixing an initial amount of a carboxylic acid with at least one of an alpha-hydroxy acid and an alpha-hydroxy ester;

esterifying a first portion of the initial amount of the carboxylic acid to from an alpha-acyloxy derivative of the at least one of an alpha-hydroxy acid and an alpha-hydroxy ester, the esterifying producing an amount of water;

recovering a second portion of the initial amount of the carboxylic acid in combination with at least some of the amount of water; and

transforming the alpha-acyloxy derivative into an alpha, beta-unsaturated derivative.

2. The method of claim 1 wherein the at least one of an alpha-hydroxy acid and an alpha-hydroxy ester comprises a member of the group consisting of lactic acid and methyl lactate.

3. The method of claim 1 wherein the esterifying is performed in the presence of an acid catalyst.

4. The method of claim 3 wherein the acid catalyst comprises a solid acid catalyst.

5. The method of claim 1 wherein the carboxylic acid is acetic acid and the alpha-acyloxy derivative is the alpha-acetoxy derivative.

6. The method of claim 5 wherein the acetic acid is provided in glacial form.

7. The method of claim 1 wherein the at least one of an alpha-hydroxy acid and an alpha-hydroxy ester is an alpha-hydroxy ester, and wherein the carboxylic acid comprises a boiling point below the boiling point of the alpha-hydroxy ester.

8. The method of claim 1 wherein the at least one of an alpha-hydroxy acid and an alpha-hydroxy ester is an alpha-hydroxy acid, and wherein the carboxylic acid comprises a boiling point below the boiling point of the alpha-hydroxy acid.

9. The method of claim 1 further comprising collecting the alpha, beta-unsaturated derivative in an anhydrous form.

10. A method of forming an alpha-acetoxy compound comprising:

providing a reactant comprising an alpha-hydroxyl group;

providing acetic acid;

reacting the alpha-hydroxyl group with the acetic acid to form an alpha-acetoxy compound; and

collecting the alpha-acetoxy compound.

11. The method of claim 10 wherein the providing acetic acid comprises providing glacial acetic acid.

12. The method of claim 10 wherein the reactant comprising an alpha-hydroxyl group is provided in anhydrous form.

13. A method of derivitizing an alpha-hydroxy group comprising:

providing a reaction vessel having a first and second inlets and an outlet;

introducing an azeotrope forming substance through the first inlet, the azeotrope forming substance having the ability to form an azeotrope with water;

introducing a compound comprising an alpha-hydroxyl group through the second inlet;

providing a catalytic acid within the reaction vessel;

introducing a reactant having a carboxylic acid group into the reaction vessel;

reacting the alpha-hydroxy group with the carboxylic acid group to form an alpha-acyloxy product; and

collecting the alpha-acyloxy product through the outlet.

14. The method of claim 13 wherein the catalytic acid is a solid.

15. The method of claim 13 wherein the reactant having the carboxylic acid group comprises fewer than 20 carbon atoms.

16. The method of claim 13 wherein the reactant comprising the carboxylic acid group is acetic acid.

17. The method of claim 13 wherein the azeotrope forming substance and the reactant having a carboxylic acid group are the same.

18. The method of claim 13 wherein the first inlet is at a first elevation and the second inlet is at a second elevation, the second elevation being higher than the first elevation, and wherein the azeotrope forming substance flows elevationally upward after introduction through the first inlet.

19. The method of claim 18 wherein the compound comprising an alpha-hydroxyl group migrates elevationally downward after introduction through the second inlet and wherein the outlet comprises an outlet positioned at a third elevation, the third elevation being at or below the first elevation.

20. The method of claim 19 wherein the outlet is a first outlet and wherein the reaction vessel comprises a second outlet positioned at a fourth elevation, and wherein a portion of the azeotrope forming substance is collected through the second outlet.

21. A method of derivatizing an alpha-hydroxy acid comprising:

providing an alpha-hydroxy acid in a first vessel;

providing acetic acid to the first vessel;

reacting the acetic acid with the alpha-hydroxy acid to form an alpha-acetoxy acid;

transferring the alpha-acetoxy acid to a second vessel; and

performing a pyrolysis reaction within the second vessel, the pyrolysis reaction converting the alpha-acetoxy acid to an alpha, beta-unsaturated acid.

22. The method of claim 21 further comprising collecting the alpha, beta-unsaturated acid from the second vessel in an anhydrous form.

23. The method of claim 21 further comprising converting the alpha, beta-unsaturated acid to an alpha, beta-unsaturated ester.

24. The method of claim 23 wherein the alpha, beta-unsaturated ester comprises a member of the group consisting of n-butyl ester and 2-ethylhexyl ester.

25. A method of forming a compound having a formula

26. The method of claim 25 wherein the catalyst is selected from the group consisting of sulfuric acid, polysulfonic acid, polyphosphoric acid and a solid acid catalyst.

27. The method of claim 25 wherein the providing the second reactant comprises providing the second reactant in gaseous form.

28. The method of claim 25 further comprising collecting the compound, wherein the providing the first reactant comprises providing a molar quantity of the first reactant and wherein the collecting the compound comprises collecting a molar quantity of the compound, the molar quantity of the compound being about 90% of the molar quantity of the first reactant.

29. The method of claim 25 further comprising:

providing a reaction column comprising;

a first inlet at a first elevation;

a second inlet at a second elevation;

a product outlet; and

collecting the initial product through the product outlet;

wherein the providing the first reactant comprises providing the first reactant through the first inlet, and the providing the second reactant comprises providing the second reactant through the second inlet.

30. The method of claim 29 wherein the first elevation is at a higher elevation on the column than the second elevation.

31. The method of claim 29 wherein the column further comprises a recovery outlet elevationally higher than the product outlet, wherein the providing the second reactant comprises providing an initial amount, and wherein a portion of the initial amount is recovered through the recovery outlet.

32. The method of claim 29 wherein the transforming comprises:

providing the initial product to a reactor; and

performing a pyrolysis reaction within the reactor.

33. The method of claim 32 wherein R₅═

CH₃ and wherein the pyrolysis reaction produces acetic acid.

34. The method of claim 29 wherein the catalyst comprises a solid acid catalyst.

35. A method of producing an acrylate ester comprising:

providing a first reactant comprising at least one of lactic acid and a lactic acid ester

providing a carboxylic acid;

esterifying the carboxylic acid to form an alpha-acyloxy derivative of the first reactant;

converting the alpha-acyloxy derivative to the corresponding acrylic acid or first acrylate ester and

converting the acrylic acid or first acrylate ester to a second acrylate ester.

36. A method of forming a compound having a formula

37. The method of claim 36 wherein R₆≠

R₁, and wherein R₆ is selected from the group consisting of methyl, ethyl, n-butyl and 2-ethylhexyl.

38. The method of claim 36 wherein R₆≠

R₁, and wherein R₁ is selected form the group consisting of CH₃, CH₂CH₃, and H.

39. The method of claim 36 wherein the transforming comprises:

forming an alpha, beta-unsaturated compound in the second vessel, the alpha, beta-unsaturated compound having the formula

distilling the alpha, beta-unsaturated compound; and

after the distilling, reacting the alpha, beta-unsaturated compound with a compound of the formula HOR₆ to esterify at least some of the alpha, beta-unsaturated compound to replace R₁ with R₆.

40. A process for forming an acrylate comprising:

introducing an amount of one of lactic acid or a lactic acid ester into a first vessel;

introducing a molar excess of acetic acid relative to the amount of lactic acid or lactic acid ester into the first vessel,

reacting the lactic acid or lactic acid ester with a first portion of the acetic acid in the presence of a first catalyst to produce the corresponding 2-acetoxy propionic acid or ester;

recycling a non-reacted portion of the acetic acid;

transferring the 2-acetoxy propionic acid or ester to a second vessel;

providing a second catalyst in the second vessel;

within the second vessel, liberating acetic acid from the 2-acetoxy propionic acid or ester to produce the corresponding acrylic acid or first acrylate ester;

removing the liberated acetic acid by distillation of the acrylic acid or first acrylate ester;

after the removing, mixing the acrylic acid or first acrylate ester with an alcohol; and

esterifying the acrylic acid or trans-esterifying the first acrylate ester by reaction with the alcohol to form a second acrylate ester.

41. The method of claim 40 wherein the alcohol is selected from the group consisting of butanol and 2-ethyl hexanol.

42. The method of claim 40 wherein the esterifying the acid or trans-esterifying the acrylate ester by reaction with the alcohol comprises reactive distillation and wherein an unreacted portion of the alcohol is collected and recycled.

43. The method of claim 40 wherein the non-reacted portion of acetic acid forms an azeotrope in the first vessel and wherein the recycling the non-reacted portion comprises collecting and drying the non-reacted portion to remove at least some of any water present in the collected non-reacted portion.

44. The method of claim 40 wherein the second catalyst comprises calcium sulfate.