Synthesis and characterization of an organic reagent 4-(6-bromo-2-benzothiazolylazo) pyrogallol and its analytical application.

Organic reagent, 4-(6-Bromo-2-Benzothiazolylazo) pyrogallol (4-Br-BTAP), was synthesized by coupling reaction of diazotized 2-amino-6-bromobenzothiazole with pyrogallol and purified using ethanol recrystallization method. Analysis and characterization of synthesized product were carried out using melting point, elementary analysis, IR and H¹-NMR. Dissociation constants of the organic reagent were calculated by spectrophotometric method. Absorption spectra of the 4-Br-BTAP in solvents of different polarities were investigated. Analytical application of 4-Br-BTAP was established with Cu (II) and Pd (II).