p-Acetamidophenol-azo-derivatives (I–IV) were prepared by
coupling p-acetamidophenol with aryl, p-bromo-, p-methoxy- and
p-nitro-diazonium chloride, in an ice bath, in the presence of
sodium hydroxide [19]. The precipitates were left in refrigerator
over night, filtered and crystallized from acetic acid (yield 78–86%)