# US 5,347,022 A · Preparation of DI- or triarylmethane dyes by oxidation

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- Number: US 5,347,022 A
- Document ID: US5347022A
- Status: Granted
- Kind: A
- Application number: 08/038,865
- Filed: 1993-03-29
- Granted: 1994-09-13
- Earliest claimed: 1992-04-08
- Assignees: BASF SE
- Inventors: Thomas Gessner; Udo Mayer
- Web page: https://patentgrep.com/patent/US5347022A

## CPC

- C09B 11/18: Preparation by oxidation
- C09B 11/02: derived from diarylmethanes
- C09B: ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES {, e.g. PIGMENTS}; MORDANTS; LAKES (fermentation or enzyme using processes to synthesise a desired chemical compound C12P)

## Abstract

A process for preparing di- or triarylmethane dyes by oxidation of di- or triarylmethanes in the presence of a diluent and of an oxygen transfer catalyst that contains a complexed heavy metal ion or of a catalyst based on molybdenic acid and vanadium compounds comprises using as oxidizing agent peroxomonosulfuric acid or a salt thereof.

## Claims

### Claim 1

A process for preparing dyes of the formula I ##STR12## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently of one another C.sub.1 -C.sub.8 -alkyl which may be substituted and may be interrupted by from 1 to 3 oxygen atoms in the ether function, phenyl or C.sub.1 -C.sub.4 -alkylphenyl, and
R.sup.5 and R.sup.6 are independently of one another hydrogen or methyl,
X is hydrogen, substituted or unsubstituted phenyl or substituted or unsubstituted naphthyl, and
An.sup..crclbar. is an anion, by oxidation of a leuco compound of the formula II ##STR13## where R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and X are each as defined above, in the presence of a diluent, peroxomonosulfuric acid or a salt thereof as oxidizing agent, and a catalyst consisting essentially of an oxygen transfer catalyst which contains a complexed heavy metal ion; or molybdenic acid in admixture with vanadium in the form of VO.sup.2.sym. ions or pentavalent vanadium compounds.

### Claim 2 (depends on 1)

A process as claimed in claim 1, wherein R.sup.5 and R.sup.6 are each hydrogen.

### Claim 3 (depends on 1)

A process as claimed in claim 1, wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each substituted or unsubstituted C.sub.1 -C.sub.4 -alkyl.

### Claim 4 (depends on 1)

A process as claimed in claim 1, wherein X is hydrogen or substituted or unsubstituted phenyl.

### Claim 5 (depends on 1)

A process as claimed in claim 1, wherein the oxygen transfer catalyst is a member of the class of the porphyrins, tetraaz[14]annulenes, phthalocyanines or tetraazacyclotetradecanes.

### Claim 6 (depends on 1)

A process as claimed in claim 1, wherein the heavy metal ion complexed within the oxygen transfer catalyst is derived from iron, manganese, cobalt or chromium.