# US 4,376,223 A · Method for promoting aluminum chloride catalyzed isomerization of sym octahydrophenanthrene to sym-octahydroanthracene with aryl phenone

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- Number: US 4,376,223 A
- Document ID: US4376223A
- Status: Granted
- Kind: A
- Application number: 06/372,057
- Filed: 1982-04-26
- Granted: 1983-03-08
- Earliest claimed: 1982-04-26
- Assignees: Koppers Company, Inc.
- Inventors: William T. Gormley
- Web page: https://patentgrep.com/patent/US4376223A

## CPC

- C07C 5/2266: {with hydrides or organic compounds (C07C5/2246 takes precedence)}
- C07C 2527/125: Compounds comprising a halogen and scandium, yttrium, aluminium, gallium, indium or thallium
- C07C 2527/126: Aluminium chloride
- C07C 2531/02: containing organic compounds or metal hydrides
- C07C 2603/24: Anthracenes; Hydrogenated anthracenes
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

A method is disclosed for promoting isomerization of sym-octahydrophenanthrene (s-OHP) to sym-octahydroanthracene (s-OHA) in the presence of a catalyst provided by aluminum chloride or aluminum bromide, or a mixture of these two compounds. The rate of isomerization is increased by having the reaction run in the presence of an aryl phenone such as benzophenone.

## Claims

### Claim 1

In a process for the isomerization of sym-octahydrophenanthrene to sym-octahydroanthracene in the presence of a catalyst comprising AlCl.sub.3 or AlBr.sub.3, or a mixture thereof, the improvement which comprises using an effective amount of an aryl phenone as a promoter to the catalyst to increase the rate of isomerization as compared with the rate of the unpromoted catalyst whereby the isomerization may be carried out at room temperature.

### Claim 2 (depends on 1)

The process of claim 1 wherein the aryl phenone is selected from a group of compounds represented by the general formula ##STR4## wherein each Ar may be independently selected from a phenyl group, a monomethyl-substituted phenyl group and a dimmethyl-substituted phenyl group.

### Claim 3 (depends on 1)

The process of claim 1 wherein said promoter has the structural formula ##STR5##

### Claim 4 (depends on 1)

The process of claim 1 wherein said catalyst is present in an amount in a range from about 5 to about 15 percent by weight based upon the sym-octahydrophenanthrene initially present and wherein said promoter is present in an amount in a range from about 5 weight percent to about 50 weight percent based upon the amount of catalyst present.