It is distinguished by the presence of a sulfonylaminophenyl group, which renders the material particularly insoluble (resistant to migration).

It is derived from two fairly complicated precursors.

The azo component is made from a dimethoxyaniline with the sulfonylaminophenyl substituent.he compound is obtained via acetoacetylation of o-tolidine using diketene.

The resulting bisacetoacetylated compound is coupled with two equiv of the diazonium salt obtained from 2,4-dichloroaniline.

[1] Although it is often depicted as an azo compound, X-ray crystallography shows that the molecule exists as a hydrazone.