Spectroscopic Determination and Evaluation of Acidity Constants for Some Drug Precursor 2-Amino-4-(3- or 4-substituted phenyl) Thiazole Derivatives

Acid dissociation constants, Ka, of eight drug precursor 2-amino-4-(3- or 4-substituted phenyl) thiazole derivatives were determined using a UV−vis spectroscopic technique. The obtained Ka values were evaluated by structure elucidation and a protonation mechanism. The obtained tautomerization equilibrium constants, KT, indicated the predominance of amino forms for all studied compounds.

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