Water-soluble tetrakisazo dyestuffs derived from 4,4{40 -diaminoazobenzene

摘要

Dyestuffs of the formula: <IMAGE> (I) in which C2 represents the radical of the formula: <IMAGE> where X is NH2 or OH, C1 and C3 are different residues of molecules C1H and C3H free from azo groups and selected from the group consisting of acetylacetic derivatives, pyrazolonic derivatives, benzenic derivatives, and naphthalenic derivatives, only one of the molecules C1H and C3H being a naphthalenic derivative, one at least of the residues C1 and C3 having at least one and at most two sulphonic acid groups, and n having the value 0 or 1 and leather colored with such dyestuffs.