IP Library Granted Patent US 11,512,043
Granted Patent B2
US 11,512,043 · App. 17/262,735 · Granted Nov 29, 2022

Process for preparing N-methyl(meth)acrylamide

Inventors: Marcel Treskow (Darmstadt, DE); Doris Saal (Bensheim, DE); Thorben Schütz (Alsbach-Hähnlein, DE); Steffen Krill (Mühltal, DE)
Assignee: Evonik Operations GmbH
C07C231/02C07C231/24C08F220/56
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Quick Facts
Patent No.
US 11,512,043
App. No.
17/262,735
Granted
Nov 29, 2022
Kind
B2
Abstract

The invention relates to a process for preparing N-methyl(meth)acrylamide and to the uses thereof.

Claims (23)

1. A process for preparing N-methyl(meth)acrylamide, comprising reacting (meth)acrylic anhydride with methylamine, wherein:

a) the methylamine has a water content of <1% by weight;

b) the molar ratio of (meth)acrylic anhydride:amine is 1:x wherein 1≤x<2;

and wherein the reaction has a yield of greater than 90%.

2. The process of claim 1 , wherein the reaction is performed in the presence of a stabilizer.

3. The process of claim 2 , wherein the stabilizer is selected from the group consisting of: phenothiazine, 2,4-dimethyl-6-tert-butylphenol, N,N′-diphenyl-p-phenylenediamine, 4-hydroxy-2,2,6,6-tetramethylpiperidinooxyl, 4-methyl-2,6-di-tert-butylphenol, 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, benzene-1,4-diamine, N,N′-mixed phenyl and tolyl derivatives (DTPD), 2,6-di-tert-butyl-alpha-(dimethylamino)-p-cresol, tert-butylcatechol, bis-2,2,6,6-tetramethyl-4-piperidyl sebacate, 2,2,6,6-tetramethylpiperidine N-oxyl and mixtures thereof.

4. The process of claim 1 , wherein the water content of the methylamine is less than 0.1% by weight.

5. The process of claim 1 , wherein the water content of the reaction mixture after the end of addition of all reactants is less than 10% by weight.

6. The process of claim 5 , wherein the water content of the reaction mixture after the end of addition of all reactants is less than 5% by weight.

7. The process of claim 5 , wherein the water content of the reaction mixture after the end of addition of all reactants is less than 1% by weight.

8. The process of claim 5 , wherein the water content of the reaction mixture after the end of addition of all reactants is less than 0.1% by weight.

9. The process of claim 1 , wherein the reaction is conducted in a polar aprotic solvent.

10. The process of claim 1 , wherein the methylamine is added in liquid or gaseous form.

11. The process of claim 1 , wherein the methylamine is added as a gas.

12. The process of claim 1 , wherein the molar ratio of (meth)acrylic anhydride:amine is from 1:1 to 1:1.5.

13. The process of claim 1 , wherein the (meth)acrylic acid by-product is removed or separated by distillation.

14. The process of claim 1 , wherein the (meth)acrylic anhydride is reacted with methylamine at temperatures between −20° C. and 100° C.

15. The process of claim 1 , wherein the (meth)acrylic anhydride is reacted with methylamine at a temperature between 0° C. and 80° C.

16. The process of claim 1 , wherein the (meth)acrylic anhydride is reacted with methylamine at a temperature between 20° C. and 50° C.

17. The process of claim 1 , wherein the (meth)acrylic anhydride is reacted with methylamine at an absolute pressure of 0.5 bar to 10 bar.

18. The process of claim 1 , wherein the (meth)acrylic anhydride is reacted with methylamine at an absolute pressure of 1 bar to 5 bar.

19. The process of claim 3 , wherein the (meth)acrylic anhydride is reacted with methylamine at an absolute pressure of 0.5 bar to 10 bar.

20. The process of claim 19 , wherein the molar ratio of (meth)acrylic anhydride:amine is 1:1.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 8, 2021
From: TRESKOW, MARCEL; SAAL, DORIS; SCHÜTZ, THORBEN; KRILL, STEFFEN
To: EVONIK OPERATIONS GMBH
Reel/Frame 055861/0192 →
Priority Claims (1)
EP 18185792 · Jul 26, 2018 · regional
Continuity (1)
Related Publication 20220112154A1 · Apr 14, 2022