Preparation of Di- or triarylmethane dyes by oxidation
AssigneeBASF SE
InventorsThomas Gessner, Udo Mayer
Life of this patent
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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 comprises using as oxidizing agent hydrogen peroxide, a hydrogen peroxide donor compound, an organic hydroperoxide or a percarboxylic acid and as the oxygen transfer catalyst a member of the class of the porphyrins, tetraaza[14]annulenes, phthalocyanines or tetraazacyclotetradecanes.
Claims7
A process for preparing dyes of the formula I ##STR13## 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 ##STR14## 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 and in the absence of chlorinal, which comprises using as oxidizing agent hydrogen peroxide, a hydrogen peroxide donor compound selected from alkali metal persborates or percarbonates, an organic hydroperoxide or a percarboxylic acid in the presence of an oxygen transfer catalyst consisting essentially of a complexed heavy metal ion-containing compound selected from the group consisting of the porphyrins, tetraaza[14]annulenes, phthalocyanines and tetraazacyclodecanes.
A process for preparing a dye of the formula (I) ##STR15## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently C.sub.1 -C.sub.8 -alkyl, phenyl or C.sub.1 -C.sub.4 -alkylphenyl, in which said C.sub.1 -C.sub.8 -alkyl may be substituted and may be interrupted by from 1 to 3 oxygen atoms in an ether function,
- R.sup.5 and R.sup.6 are independently hydrogen or methyl,
- X is hydrogen, substituted or unsubstituted phenyl or substituted or unsubstituted naphthyl, and
- An.sup..crclbar. is an anion, comprising
- oxidizing a leuco compound of the formula II ##STR16## 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) a diluent,
- (b) an oxidizing agent selected from the group consisting of hydrogen peroxide, a hydrogen peroxide donor compound selected from alkali metal perborates or percarbonates, an organic hydroperoxide and a percarboxylic acid and
- (c) an oxygen transfer catalyst consisting essentially of
- (i) a compound selected from the group consisting of porphyrins, tetraaza[14]annulenes, phthalocyanines and tetraazacyclodecanes and
- (ii) a heavy metal complexed therein, and in the absence of chlorinal.
Dependencies are inferred from the claim text.