Preparation of Di- or triarylmethane dyes by oxidation

摘要

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.