Method for producing N-isopropyl(meth)acrylamide

Patent metadata

Field	Value
Publication number	US-9512062-B2
Application number	US-200913119244-A
Country	US
Kind code	B2
Filing date	Nov 19, 2009
Priority date	Dec 15, 2008
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A novel process is described which allows N-isopropyl(meth)acrylamide to be obtained in high purity and yield in a simple manner, by reacting methacrylic anhydride with isopropylamine, optionally in a solvent.

First claim

The invention claimed is:

1. A process for preparing an amide of (meth)acrylic anhydride, the process comprising:
metering an amine, which is a primary or a secondary amine, into a mixture consisting of (meth)acrylic anhydride and a polymerization inhibitor at a maximum metering temperature of 35° C. so that the amine reacts with the anhydride in the presence of the polymerization inhibitor at a maximum reaction temperature of 45° C. to yield the amide and a mother liquor comprising (meth)acrylic anhydride; and
removing the amide from the mother liquor.

2. The process according to claim 1 , further comprising
neutralizing the mother liquor after said removing to precipitate out further amide; and
removing the further amide.

3. The process according to claim 1 , further comprising
distilling the mother liquor after said removing to remove (meth)acrylic acid and obtain a distillation residue comprising further amide; and
removing the further amide.

4. The process according to claim 1 , wherein
the amine is a primary amine.

5. The process according to claim 1 , wherein
the amine is a secondary amine.

6. A process for preparing N-isopropylmethacrylamide, the process comprising:
metering isopropylamine into a mixture consisting of methacrylic anhydride and a polymerization inhibitor at a maximum metering temperature of 30° C. so that methacrylic anhydride reacts with isopropylamine to yield N-isopropylmethacrylamide in the presence of the polymerization inhibitor at a maximum reaction temperature of 40° C.; and
isolating N-isopropylmethacrylamide.

7. A method for preparing a polymer or copolymer, the method comprising:
metering an amine, which is a primary or a secondary amine, into a mixture consisting of (meth)acrylic anhydride and a polymerization inhibitor at a maximum metering temperature of 35° C. so that the amine reacts with the anhydride in the presence of the polymerization inhibitor at a maximum reaction temperature of 45° C. to yield an amide and a mother liquor comprising (meth)acrylic anhydride; and
removing the amide from the mother liquor
polymerizing a monomer comprising the amide of (meth)acrylic anhydride to obtain the polymer or copolymer.

8. A process for preparing an amide of an unsaturated carboxylic acid, the process comprising:
metering an amine, which is a primary or a secondary amine, into a mixture consisting of an anhydride of the unsaturated carboxylic acid, and a polymerization inhibitor at a maximum metering temperature of 30° C. so that the anhydride reacts with the amine in the presence of the polymerization inhibitor to form the amide and a mother liquor comprising the unsaturated carboxylic acid; and
removing the amide from the mother liquor.

9. The process according to claim 8 , wherein the anhydride of the unsaturated carboxylic acid is an anhydride of an unsaturated aliphatic carboxylic acid.

10. The process according to claim 9 , wherein the anhydride of the unsaturated aliphatic carboxylic acid is selected from the group consisting of acrylic anhydride, methacrylic anhydride, and itaconic anhydride.

Assignees

• Knebel Joachim
• Karnbrock Wilhelm
• Kerscher Volker
• Evonik Roehm Gmbh

Inventors

• Knebel Joachim
• Karnbrock Wilhelm
• Kerscher Volker

Classifications

• C07C231/02 Primary

  from carboxylic acids or from esters, anhydrides, or halides thereof by reaction with ammonia or amines · CPC title

• C07C249/08

  by reaction of hydroxylamines with carbonyl compounds · CPC title

• C08F220/56

  Acrylamide; Methacrylamide · CPC title

• C07C273/1854

  by reactions not involving the formation of the N-C(O)-N- moiety · CPC title

• C07C233/09

  with carbon atoms of carboxamide groups bound to carbon atoms of an acyclic unsaturated carbon skeleton · CPC title