Verfahren zur Herstellung von carbonsaeure- und sulfonsaeuregruppenfreien Mono- und Disazofarbstoffen

摘要

The invention comprises mono- and disazo dyes which are free from carboxylic and sulphonic acid groups and are of formula:- wherein R1 is an alkyl group, R2 is an alkyl, hydroxyalkyl or phenyl group or a hydrogen atom and R1 and R2 may be joined to form a heterocyclic ring and R3 is the radical of a diazo component of the isocyclic aromatic or heterocyclic aromatic series. They are prepared by diazotising an amine, e.g. an amino-benzene or -naphthalene, aminoazobenzene, aminothiophene, aminobenzthiazole, amino-triazole or aminobenztriazole and coupling the diazo compound with a perimidine of formula:- The dyes give blue shades on polyester, polyamide and cellulose ester fibres. In examples: (1) 2-chloro-4-nitroaniline or 2-methyl-5-methoxy-4-amino-azobenzene is diazotised and coupled with the perimidine of formulae:- or 1 : 2-dimethyl-perimidine; (2) 2-aminothiazole is diazotised and coupled with the perimidine of formula:- Further dyes are specified in examples.