# US 4,400,537 A · Process for 1,4-phenylenediamine

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- Number: US 4,400,537 A
- Document ID: US4400537A
- Status: Granted
- Kind: A
- Application number: 06/369,499
- Filed: 1982-04-19
- Granted: 1983-08-23
- Earliest claimed: 1977-09-28
- Assignees: Standard Oil Company (Indiana)
- Inventors: Thomas A. Weil
- Web page: https://patentgrep.com/patent/US4400537A

## CPC

- C07C 209/18: with formation of amino groups bound to carbon atoms of six-membered aromatic rings or from amines having nitrogen atoms bound to carbon atoms of six-membered aromatic rings
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

A process for the preparation of 1,4-phenylenediamine from 1,4-dihydroxybenzene at a temperature within the range of from about 300.degree. C. to 450.degree. C. and a pressure of from atmospheric to 3000 psig in the presence of an aminating agent, an inert hydrocarbon and an acidic alumina catalyst. p-Aminophenol can be aminated to 1,4-phenylenediamine with the same process.

## Claims

### Claim 1

A process for the amination of a hydroxy aromatic selected from the group consisting essentially of 1,4-dihydroxybenzene and p-aminophenol which comprises reacting said hydroxy aromatic with an aminating agent in the presence of an inert liquid hydrocarbon with a boiling point in the range of from about 25.degree. C. to 400.degree. C., and an alumina catalyst selected from the group consisting of alpha alumina, gamma alumina and eta alumina catalysts at a temperature within the range of from about 300.degree. C. to 450.degree. C., a pressure from atmospheric to about 3000 psig wherein the concentration of said catalyst is within the range of from about 1:1 to about 1:10, weight of hydroxy aromatic to weight of catalyst and the mole ratio of aminating agent as ammonia to reactant is at least 20:1, aminating agent to reactant.

### Claim 2 (depends on 1)

The process of claim 1 wherein said aminating agent is selected from the group consisting of ammonia, ammonium chloride, ammonium bromide, ammonium iodide, ammonium hydroxide, ammonium nitrate, ammonium carbonate, methylamine, dimethylamine, ethylamine and diethylamine.

### Claim 3 (depends on 2)

The process of claim 2 wherein said aminating agent is ammonia.

### Claim 4 (depends on 1)

The process of claim 1 wherein the mole ratio of aminating agent as ammonia to reactant is within the range of about 70:1 to about 150:1, aminating agent to reactant.

### Claim 5 (depends on 1)

The process of claim 1 wherein said inert hydrocarbon is selected from the group consisting of benzene, toluene, xylene, cyclohexane, hexane, heptane, octane, nonane and decane.

### Claim 6 (depends on 1)

The process of claim 1 wherein the said catalyst is selected from the group consisting of alpha alumina catalysts, gamma alumina catalysts, eta alumina catalysts and silica-alumina catalysts.

### Claim 7 (depends on 1)

The process of claim 1 wherein the concentration of said catalyst is within the range of from about 1:1 to about 1:5, weight of hydroxy aromatic to weight of catalyst.

### Claim 8 (depends on 1)

The process of claim 1 wherein temperature is within the range of from about 325.degree. C. to about 400.degree. C.