# US 8,772,546 B2 · 1,2-diaminocyclohexane and chemical process

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- Number: US 8,772,546 B2
- Document ID: US8772546B2
- Status: Granted
- Kind: B2
- Application number: 12/612,361
- Filed: 2009-11-04
- Published: 2010-05-20
- Granted: 2014-07-08
- Earliest claimed: 2008-11-18
- Assignees: Invista North America S.A.R.L.
- Applicants: Ronald L. Amey
- Inventors: Ronald L. Amey
- Web page: https://patentgrep.com/patent/US8772546B2

## CPC

- C07C 209/72: by reduction of six-membered aromatic rings
- C07C 2601/14: The ring being saturated
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

Disclosed is a process for the preparation of 1,2-cycloaliphatic diamines from 1,2-aromatic diamines. In one embodiment, the process provides a method for making 1,2-diaminocyclohexane by the reaction of 1,2-phenylenediamine contained in a polar, protic solvent with hydrogen in the presence of a supported rhodium catalyst, ammonia, and an inorganic borohydride, and having enhanced overall conversion and selectivity.

## Claims

### Claim 1

A process for making 1,2-cycloaliphatic diamines comprising contacting a 1,2-aromatic diamine with hydrogen in polar, protic solvent in the presence of an inorganic borohydride, ammonia and a heterogeneous catalyst comprising at least one selected from the group consisting of Ru, Rh, Pd and Pt.

### Claim 2 (depends on 1)

The process of claim 1 wherein said polar, protic solvent has the structure ROH where R is hydrogen or an alkyl group.

### Claim 3 (depends on 2)

The process of claim 2 wherein said alkyl group has from 1 to 6 carbons.

### Claim 4 (depends on 1)

The process of claim 1 wherein said inorganic borohydride is an alkali metal borohydride.

### Claim 5 (depends on 4)

The process of claim 4 wherein said inorganic borohydride is selected from the group consisting of sodium borohydride, lithium borohydride, potassium borohydride, and sodium cyanoborohydride.

### Claim 6 (depends on 5)

The process of claim 5 wherein said inorganic borohydride is sodium borohydride.

### Claim 7 (depends on 1)

The process of claim 1 wherein said heterogeneous catalyst comprises at least one selected from the group consisting of Ru and Rh.

### Claim 8 (depends on 1)

The process of claim 1 wherein the sum of the weights of Ru, Rh, Pd and Pt comprises from 1 to 10 weight percent of said heterogeneous catalyst.

### Claim 9 (depends on 8)

The process of claim 8 wherein the sum of the weights of Ru, Rh, Pd and Pt comprises from 3 to 5 weight percent of said heterogeneous catalyst.

### Claim 10 (depends on 1)

The process of claim 1 wherein said heterogeneous catalyst comprises an oxide of at least one selected from the group consisting of Ru, Rh, Pd and Pt.

### Claim 11 (depends on 10)

The process of claim 10 wherein said heterogeneous catalyst consists essentially of said oxide.

### Claim 12 (depends on 8)

The process of claim 8 wherein said heterogeneous catalyst comprises a support that is substantially inert to amines under reaction conditions for converting 1,2-aromatic diamines to cycloaliphatic diamines.

### Claim 13 (depends on 8)

The process of claim 8 wherein said heterogeneous catalyst comprises at least one support selected from the group consisting of alumina, titania, zeolites and microporous layered materials.

### Claim 14 (depends on 1)

The process of claim 1 further comprising contacting with hydrogen at a temperature from about 120° to about 200° C., and at a pressure of from about 1000 to about 2500 psig.

### Claim 15

A process for making 1,2-diaminocyclohexane comprising contacting 1,2-phenylenediamine contained in a polar, protic solvent with hydrogen in the presence of an inorganic borohydride, ammonia and a supported rhodium catalyst, wherein said polar, protic solvent is selected from the group consisting of water, methanol, ethanol, isopropanol, and mixtures thereof.

### Claim 16 (depends on 15)

The process of claim 15 further comprising contacting with hydrogen at a temperature from about 120° to about 200° C., and at a pressure of from about 1000 to about 2500 psig.

### Claim 17 (depends on 15)

The process of claim 15 wherein said supported rhodium catalyst comprises rhodium on carbon and wherein said supported rhodium catalyst contains from about 1 to about 10 weight percent rhodium.

### Claim 18 (depends on 15)

The process of claim 15 wherein said supported rhodium catalyst contains from about 3 to about 5 weight percent rhodium.

### Claim 19 (depends on 1)

The process of claim 1, wherein the process is an aqueous process.

### Claim 20 (depends on 15)

The process of claim 15, wherein the process is an aqueous process.