abstract |
(57) Abstract: The invention relates, as the formula A-E-SO 2 -NH- SO 2 -E-A (I) [wherein, -E- and -A are described herein And mixtures of compounds having formula (I), and their use as (bis) coupling components for the preparation of azo dyes and metal complexes. [Effect] As a dye, it is particularly useful for dyeing leather. |