GB431708A - Process for the manufacture of acid safranine dyestuffs - Google Patents

Abstract

Safranine dyestuffs which dye wool greenish blue shades are obtained by condensing isorosinduline sulphonic acids of the formula <FORM:0431708/IV/1> in which R1 and R2 are alkyl, aralkyl or aryl, with aromatic 1 : 4 diamines which are not substituted in both amino groups and contain in the 2-position an alkyl group or in the 2 and 6 positions neutral substituents such as alkyl, oxyalkyl or halogen. Sulphonic groups may be introduced into the safranines by sulphonation or sulphonated 1 : 4-diamines may be used, and the products may be treated with alkylating or acylating agents. In examples: (1) the isorosindulinetrisulphonic acid obtainable from 4<1>-acetylamino-2<1>-sulphophenyl-b -naphthylamine and 4-aminodiethylaniline-3-sulphonic acid or 11 : 13-dichlor diethylisorosinduline-1 : 6-disulphonic acid is heated with 2 : 6-dimethyl-1 : 4-diaminobenzene to give the corresponding safranine; (2) diethylisorosinduline - 11 - methyl - 1 : 6 - disulphonic acid is condensed with toluylenediamine or 2 : 6-dichlor-1 : 4-phenylenediamine and then treated with oleum; (3) 2 : 6-dimethyl-1 : 4-diaminobenzene-3-sodium suphonate is condensed with 11 - methyl - diethylisorosinduline - 1 : 6 - disulphonic acid or 11-methyl-14-chlor-diethylisorosinduline-1 : 6-disulphonic acid. 2 : 6 - Dimethyl - 1 : 4 - diaminobenzene - 3 - sulphonic acid may be prepared by coupling a diazo compound with 1-amino-2 : 6-dimethylbenzene, reducing the azo compound to 2 : 6-dimethyl-1 : 4-phenylenediamine and sulphonating the latter.