Antrhachinon-Azo-Farbstoffe sowie Verfahren zu ihrer Herstellung

摘要

Anthraquinone-monoazo dyes of formula in which one of R and R1 is hydrogen, the other being a methyl group are prepared by diazotizing 1-amino-anthraquinone and coupling, to 3 - hydroxy - 2 - naphtho - 21,41- or 21-, 61-dimethylanilide or by oxidation of the leucosulphuric acid ester of the anthraquinone-monoazo dye in presence of a small amount of polymeric N-vinyl-a -pyrrolidone. The dyes give red dyeings on polyester materials.