Process for preparing diacid compounds

Patent metadata

Field	Value
Publication number	US-9382182-B2
Application number	US-201314415491-A
Country	US
Kind code	B2
Filing date	Jun 26, 2013
Priority date	Jul 19, 2012
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

The present invention relates to a process for preparing at least one diacid compound, comprising a step of hydrolysis reaction of at least one imide compound, performed in the absence of catalyst.

First claim

The invention claimed is:

1. A process for preparing at least one diacid compound, comprising hydrolyzing, in the absence of any acidic or basic catalyst, at least one imide compound; wherein the step of hydrolyzing is performed at a temperature of from 160° C. to 220° C. and wherein the duration of the step of hydrolyzing is from 30 minutes to 6 hours.

2. The process as claimed in claim 1 , wherein the at least one imide compound is a compound or a mixture of compounds of general formula (I) below:

and the at least one diacid compound is a compound or a mixture of compounds of general formula (II) below:

wherein -A- represents a linear or branched, saturated or unsaturated divalent hydrocarbon-based radical comprising from 2 to 12 carbon atoms.

3. The process as claimed in claim 2 , wherein -A- represents a saturated divalent hydrocarbon-based radical comprising from 2 to 6 carbon atoms.

4. The process as claimed in claim 2 , wherein -A- represents a divalent hydrocarbon-based radical chosen from the group consisting of —CH 2 —CH 2 —CH(CH 3 )— and —CH 2 —CH(CH 2 CH 3 )— radicals.

5. The process as claimed in claim 2 , wherein the at least one imide compound is chosen from the group consisting of 2-methylglutarimide, 2-ethylsuccinimide and mixtures thereof.

6. The process as claimed in claim 2 , wherein the at least one diacid compound is chosen from the group consisting of 2-methylglutaric acid, 2-ethylsuccinic acid and mixtures thereof.

7. The process as claimed in claim 2 , wherein -A- represents an unsaturated divalent hydrocarbon-based radical comprising from 2 to 6 carbon atoms.

8. The process as claimed in claim 1 , further comprising, before the step of hydrolyzing, a step of placing the at least one imide compound in contact with water to obtain a mixture of the at least one imide compound and water.

9. The process as claimed in claim 8 , wherein, after the step of placing in contact, the mole ratio between the water and the at least one imide compound is from 10 to 100.

10. The process as claimed in claim 1 , wherein the step of hydrolyzing is performed at a temperature from 170° C. to 200°.

11. The process as claimed in claim 1 , wherein the step of hydrolyzing produces ammonia, and said ammonia is removed, and then optionally recovered by condensation.

12. The process as claimed in claim 1 , further comprising a step of recovering the at least one diacid compound.

13. The process as claimed in claim 1 , further comprising a step of purifying the at least one diacid compound by distillation.

14. The process of claim 3 , wherein -A- represents a C 2 -C 6 alkylene radical.

15. The process of claim 14 , wherein -A- represents a radical of general formula —C 4 H 8 —.

16. The process of claim 7 , wherein -A- represents a radical chosen from the group consisting of an ethylenyl radical and an o-phenylene radical.

17. The process of claim 9 , wherein the mole ratio between the water and the imide compound is from 15 to 30.

18. The process of claim 11 , wherein the ammonia is removed by stripping with nitrogen or by entrainment with water vapor.

19. The process as claimed in claim 1 , wherein the duration of the step of hydrolyzing is from 4 hours to 6 hours.

20. A process for preparing 2-methylglutaric acid, 2-ethylsuccinic acid, or a mixture thereof, comprising hydrolyzing, in the absence of any acidic or basic catalyst, 2-methylglutarimide, 2-ethylsuccinimide, or a mixture thereof; wherein the step of hydrolyzing is performed at a temperature of from 170° C. to 200° C. and wherein the duration of the step of hydrolyzing is from 4 hours to 6 hours.

Assignees

• Rhodia Operations

Inventors

• Jacquot Roland
• Rhers Bouchra

Classifications

• C07C51/00 Primary

  Preparation of carboxylic acids or their salts, halides or anhydrides (of acids by hydrolysis of oils, fats or waxes C11C) · CPC title

• C07C51/42

  Separation; Purification; Stabilisation; Use of additives · CPC title

• C07C51/44

  by distillation · CPC title

• C07C55/02

  Dicarboxylic acids · CPC title

• C07C55/12

  Glutaric acid · CPC title