ES261812A1 - Process for the production of heavy metal-containing azo dyestuffs and their use - Google Patents

Abstract

A process for the production of chromium- or cobalt-containing azo dyestuffs is characterized by diazotizing an amine of the general formula <FORM:0955506/C3/1> where A represents a radical of the benzene series free from water solubilizing groups, Acyl1 and Acyl2 represent acyl radicals derived from organic sulphonic acids or from sulphamic acids of secondary amines and in which formula the amino group and the amido group are in o-position to each other, coupling the diazonium compound with a coupling component which couples in an adjacent position to a phenolic or enolic hydroxy group or a primary or secondary amino group, then saponifying one acyl radical of the diacylamido group in the coupling product in an alkaline medium and treating the reaction product with an agent introducing chromium or cobalt, the components being so chosen that there are no salt-forming substituents which dissociate acid in water in the end product. The acyl groups in the above compounds are preferably derived from aliphatic sulphonic acids having at most 5 carbon atoms or from benzene sulphonic acids containing as nuclear substituents methyl sulphonyl or ethyl sulphonyl groups. Acyl radicals derived from sulphamic acids specified include dimethylamino, piperidino and morpholino sulphonyl radicals. Among the many products of which the preparation is described are the chromium complex of the dye obtained from N-di(methylsulphonyl)-amino-2-aminobenzene and 1-carbomethoxy - 7 - hydroxynaphthalene, acetoacetic acid-3-chloranilide and 1-(3-chlorophenyl)-3-methyl-5-pyrazolone and the cobalt complex of the dye obtained from N-di-(31-methyl-sulphonylbenzenesulphonyl) - amino - 2 - aminobenzene and 3,4-dimethyl-1-hydroxybenzene. The dyes are used for colouring synthetic and natural polyamides, e.g. wool.