| abstract |
The present invention provides compounds of formula I, in which, EITHER R1 signifies an unsubstituted or substituted (C1-4) alkyl radical, R2 signifies a hydrogen atom or an unsubstituted or substituted (C1-4) alkyl radical, OR, R1 and R2, together with the nitrogen atom to which they are attached, form a pyrrolidine, piperidine or morpholine ring, R signifies a group of formula (a) or (b), IN WHICH R3 signifies a condensed further unsubstituted or substituted pyrimidine, pyridine or benzene ring or a condensed further unsubstituted naphthalene ring, and M signifies a hydrogen ion or a cation equivalent, which compounds are useful as anionic dyes. |