# US 7,071,347 B2 · Benzofuranone stabilization of phosphate esters

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- Number: US 7,071,347 B2
- Document ID: US7071347B2
- Status: Granted
- Kind: B2
- Application number: 10/220,408
- Filed: 2001-03-01
- Published: 2006-03-23
- Granted: 2006-07-04
- Earliest claimed: 2000-03-03
- Assignees: Supresta LLC
- Inventors: Paul Albert Iacobucci; Anantha Desikan; Alan Abramson
- Web page: https://patentgrep.com/patent/US7071347B2

## CPC

- C07F 9/025: {Purification; Separation; Stabilisation; Desodorisation of organo-phosphorus compounds (of natural phosphatides C07F9/103; phosphines C07F9/5095)}
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)

## Abstract

A method for decolorizing and stabilizing alkylphenyl esters of phosphoric acid which comprises contacting the esters with an effective amount of a benzofuranone (e.g., is 5,7-di-t-butyl-3-(3,4 di-methylphenyl)3H-benzofuran-2-one) for a sufficient length of time to decolorize and stabilize the esters against subsequent color formation.

## Claims

### Claim 1

A method for decolorizing alkylphenyl esters of phosphoric acid which comprises contacting said esters with an effective amount of 5,7-di-t-butyl-3-(3,4 di-methylphenyl) 3H-benzofuran-2-one for a period of time sufficient to reduce the color to the desired level whereby said esters are decolorized and stabilized against subsequent color formation.

### Claim 2 (depends on 1)

The method of claim 1 wherein said alkylphenyl esters correspond to the formula:
wherein R is alkaryl and R1 and R2 are selected from the group consisting of alkyl, aralkyl, alkaryl and aryl, and wherein the alkyl groups contain from about 1 to about 20 carbon atoms.

### Claim 3 (depends on 2)

The method of claim 2 wherein said alkyl groups contain from 1 to about 12 carbon atoms.

### Claim 4 (depends on 1)

The method of claim 1 wherein the alkylphenyl esters contain unreacted substituted and unsubstituted phenols.

### Claim 5 (depends on 2)

The method of claim 2 wherein said decolorizing and stabilizing is conducted under an inert atmosphere.

### Claim 6 (depends on 5)

The method of claim 5 wherein said inert atmosphere comprises nitrogen.

### Claim 7 (depends on 1)

The method of claim 1 wherein the alkyl phenyl ester of phosphoric acid is an isopropylphenyl phenyl phosphate.