Isomerization of MDACH

Patent metadata

Field	Value
Publication number	US-10329238-B2
Application number	US-201615776603-A
Country	US
Kind code	B2
Filing date	Nov 30, 2016
Priority date	Dec 4, 2015
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A method for isomerizing a starting mixture comprising 2,4-diamino-1-methylcyclohexane, 2,4-MDACH for short, 2,6-diamino-1-methylcyclohexane, 2,6-MDACH for short, or mixtures thereof, wherein the isomerization is carried out in the presence of a supported catalyst with zirconium dioxide as support and ruthenium as active metal.

First claim

The invention claimed is:

1. An isomerization method, comprising:
hydrogenating a composition comprising at least one of 2,4-diaminotoluene and 2,6-diaminotoluene, to obtain a starting mixture comprising at least one of 2,4-diamino-1-methylcyclohexane and 2,6-diamino-1-methylcyclohexane;
separating the starting mixture to obtain a cis-enriched or trans-enriched mixture comprising at least one of the 2,4-diamino-1-methylcyclohexane and the 2,6-diamino-1-methylcyclohexane; and
isomerizing the cis-enriched or trans-enriched mixture in the presence of a supported catalyst with zirconium dioxide as support and ruthenium as active metal, to obtain a product mixture,
wherein the isomerizing is a cis/trans isomerization that alters the cis/trans ratio of the product mixture relative to the cis-enriched or trans-enriched mixture.

2. The method according to claim 1 , wherein the cis-enriched or trans-enriched mixture comprises at least one of the 2,4-diamino-1-methylcyclohexane and the 2,6-diamino-1-methylcyclohexane in a content of more than 95% by weight.

3. The method according to claim 1 , wherein the cis-enriched or trans-enriched mixture comprises 5 to 95% by weight of the 2,4-diamino-1-methylcyclohexane and 5 to 95% by weight of the 2,6-diamino-1-methylcyclohexane, based on a total weight of the 2,4-diamino-1-methylcyclohexane and the 2,6-diamino-1-methylcyclohexane.

4. The method according to claim 1 , wherein the isomerization is carried out at a temperature of 80 to 200° C.

5. The method according to claim 1 , wherein the isomerization is carried out continuously.

6. The method according to claim 1 , wherein the isomerizing occurs in the presence of hydrogen.

7. The method according to claim 1 , wherein the isomerizing alters the cis/trans ratio by increasing the proportion of trans isomers in the product mixture relative to the proportion of trans isomers in the cis-enriched or trans-enriched mixture.

8. The method according to claim 1 , wherein the isomerizing alters the cis/trans ratio by increasing the proportion of cis isomers in the product mixture relative to the proportion of trans isomers in the cis-enriched or trans-enriched mixture.

Assignees

• Basf Se

Inventors

• Weickgenannt Andreas
• Kramp Sandra
• Weidert Jan-Oliver
• Panchenko Alexander
• Kozicki Artur
• Busch Ralph

Classifications

• C07C209/88 Primary

  Separation of optical isomers · CPC title

• C07C2523/46

  Ruthenium, rhodium, osmium or iridium · CPC title

• C07C2521/06

  Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof · CPC title

• C07C2601/14

  The ring being saturated · CPC title

• C07C211/36

  containing at least two amino groups bound to the carbon skeleton · CPC title