Synthesis, properties and analytical application of 4-(2-benzothiazolylazo) pyrogallol

This paper reports on 4-(2-Benzothiazolylazo) pyrogallol (BTAPG), a new organic reagent, that has been synthesized by the coupled reaction of diazotized 2-aminobenzothiazole with pyrogallol, and purified using ethanol recrystallization method. Analysis and characterization of the synthesized product by means of thin-layer chromatography (TLC), elementary analysis (EA), Fourier transform infra-red absorption spectrometry (FTIR), electron impact mass spectrometry (EIMS), fast atom bombardment mass spectrometry (FABMS), nuclear magnetic resonance spectrometry (NMR) and visible absorption spectrometry (VIS) etc. indicate it to be a pure BTAPG compound with m.p. of 228 degrees C measured by differential thermal analysis. Only a brown spot with R ? 0.67 on silica HF254 thin-layer plate was found using benzene-ethyl acetate-ethyl ether-formic acid (1:1:2:20) mixed solvent as a developer in TLC. In the presence of CTMAB, a cationic surfactant, BTAPG reacts with No(VI), W(VI), Ti(IV), Zr(IV), Fe(II) and Fe(III) etc. to form the colored, ternary micelle complexes with higher sensitivities (ε 4-9 x 104 L · mol-1 · cm-t) and fairly good selectivities