Distillation of 1,2-unsaturated carboxylic acids in solution with selected amines

• US 3,893,895 A
• Filed: 07/19/1973
• Issued: 07/08/1975
• Est. Priority Date: 07/19/1972
• Status: Expired due to Term

• Current Assignee: Axel Kleemann, Ewald Noll, Gerd Schreyer, Hans Schaefer, Jurgen Dehnert, Theodor Lussling
• Original Assignee: Axel Kleemann, Ewald Noll, Gerd Schreyer, Hans Schaefer, Jurgen Dehnert, Theodor Lussling
• Inventors: Kleemann, Axel, Lussling, Theodor, Noll, Ewald, Schaefer, Hans, Schreyer, Gerd, Dehnert, Jurgen
• Primary Examiner(s): Yudkoff, Norman
• Assistant Examiner(s): Sever, Frank
• Application Number:
  US05/380,664
• Time in Patent Office: 719 Days
• Field of Search: 203/38,59,DIG.21 260/526N,29V,499
• US Class Current: 203/59
• CPC Class Codes: C07C 51/44 by distillation
• CPC Class Codes: C07C 51/487 by treatment giving rise to chemical modification by chemisorption C07C51/47
• CPC Class Codes: C07C 57/04 Acrylic acid; Methacrylic acid
• CPC Class Codes: Y10S 203/22 Accessories

Abstract

1,2-Unsaturated carboxylic acids having carbonyl compound impurities are separated by binding the carbonyl compounds with inorganic, aliphatic or aromatic amines and then distilling the acids.

Claims

1. A PROCESS FOR THE PURIFICATION OF 1,2-UNSATURATED CARBOXYLIC ACIDS CONTAINING CARBONYL COMPOUNDS COMPRISING TREATING THE IMPURE CARBOXYLIC ACID WITH AN AMINE IS SELECTED FROM THE GROUP CONSISTING OF HYDROXYLAMINE, A MONOLKYL AMINE,NAPHTHYLAMINE AND 1,2-DIANILINOETHANE TO CHEMICALLY BIND SAID CARBONYL COMPOUNDS AND THEN RECOVERING SAID CARBOXYLIC ACID BY DISTILLATION.

2. A process according to claim 1 wherein the amine is hydroxylamine.

3. A process according to claim 2 wherein the unsaturated carboxylic acid is an aliphatic carboxylic acid having 3 to 6 carbon atoms.

4. A process according to claim 2 wherein the unsaturated acid has 3 to 4 carbon atoms.

5. A process according to claim 4 wherein the acid is selected from the group consisting of acrylic acid and methacrylic acid.

6. A process according to claim 1 wherein the amine has a boiling point above 100* C.

7. A process according to claim 6 wherein the acid is selected from the group consisting of acrylic acid and methacrylic acid.

8. A process according to claim 1 wherein the amine is 1,2-dianilino-ethane.

9. A process according to claim 1 wherein the unsaturated carboxylic acid is treated with the amine at a temperature between 0* and 50* C.

10. A process according to claim 1 wherein the distillation is carried out in solution with a solvent having a higher boiling point than the unsaturated carboxylic acid.

11. A process according to claim 10 wherein 1 to 10 parts of solvent are employed per part of unsaturated carboxylic acid.

12. A process according to claim 1 wherein 0.5 to 5 equivalents of amine compound are used per equivalent of carbonyl compound.

13. A process according to claim 1 wherein the amine is hydroxylamine.

14. A process according to claim 1 wherein the amine is a monoalkyl amine.

15. A process according to claim 1 wherein the amine is naphthylamine.