New Preparation and Characterization of Reagent 1-EDBBA Derived from Para-Amino Benzoic Acid: Impact of Solvent and Limitation Isosbestic Point Study

The production of the new azo compound via a diazotization reaction between 4-aminobenzoic acid and ethyl acetoacetate is the aspect of the investigation by more than one technique FT-IR, 1H-NMR and UV-Vis spectrophotometry. The electronic absorption spectra of 1-EDBBA have been recorded and analyzed using various polar solvents. The interaction of this approach provides a way to evaluate the relative importance of various kinds of spectra to overall interaction changes in the solution. UV-Vis spectrophotometry was employed to measure the pKa and isosbestic point of reagent 1-EDBBA. The ratio of absolute ethanol to distilled water in the alcoholic solution of 1-EDBBA was 0.1:4.9. The maximal absorption is unchanged by this ratio. It indicates the pH impact of 1-EDBBA between 1 and 9.5, and 405 nm displays the 1-EDBBA’s isosbestic point. The absorbance-pH graph at specific wavelengths shows an S-shaped pattern with inflections corresponding to pKa1 and pKa2. This is dependent on the acidity of the medium.