Synthesis and characterization of 2-hydroxy-4-substituted-3 (4,6-disubstituted benzothiazolyl-2-azo)‎-benzoic acid

Abstract EN

Diazotization of 4,6-di substituted -2- amino benzothiazol with mixture of sodium nitrite and 50% sulphuric acid solution at ( 0-5 )C gave 4,6-disubstituted-2 - benzothiazoldiazonium sulphate , upon coupling with 2-hydroxy-4-substituted -5- benzoic acid gave 2-hydroxy -4-substituted 3 (4,6-disubstituted-benzothiazolyl) azo benzoic acid derivatives which charactarized by their melting points , elemental analysis , FT-IR,UV-visible, and H-NMR spectra structure formula of the prepared compounds were confirmed depending on identification results.

Acidity constants were detrmined for both carboxylic and phenolic protons .