Patent ID: 6743901
Filing Date: 2004-06-01
Classification: C09B

Abstract:
A process for preparing liquid formulations of dyes of the general formula I whereY is chlorine or bromine, Z is hydrogen, chlorine, bromine, sulfonic ester, nitro or optionally substituted sulfamoyl, R is alkylene optionally interrupted by oxygen, m is 1 or 2, n is 0 or 1, p is 0, 1 or 2, An&ominus; is the equivalent of an anion, R1 and R2 are independently hydrogen, optionally substituted alkyl, alkenyl, cycloalkyl, aralkyl or aryl or cominbe with the joining nitrogen to form a heterocycle, R3 is hydrogen or optionally substituted alkyl, B is hydrogen or C1- to C4-alkyl, B1 is hydrogen, hydroxyl, C1- to C4-alkoxy or C1- to C4-alkyl, where R4 is optionally substituted alkyl and R5 is hydrogen or C1- to C4-alkyl, and the radical may also be an optionally substituted piperazine radical, by diazotizing an amine of the formula II and then coupling the diazonium salt onto a compound of the formula III and also optionally adding solubilizing additives, which comprises effecting said diazotizing at a pH set to an acidic value using pure methanesulfonic acid or at least 20 mol % mixtures of methanesulfonic acid in monobasic acids.