The pure compound is pale yellow, but commercial samples are often colored.

The first step involves reduction with zinc in base to afford 2,2'-dichlorodiphenylhydrazine.

It undergoes chlorination (for example in water treatment plants) to give the tetrachloro derivative.

This bis(diazo) intermediate is then coupled to derivatives of acetoacetylaminobenzene (CH3C(O)CH2C(O)NHAr).

[1] This compound has been shown to increase the incidence of tumors in animals.