Various thiazoles exhibit pharmacological activity, eg, antimicrobial, antihistaminic, antiparazitic, anti- helminthic, antipyretic, and antiviral. Such medicines as Sulfathiazole, Phthalylsulfathiazole, and related compounds are widely used in medical practice. Thiazole ring is a structural component of natural compounds, eg, Vitamin B1 (thiamine), penicillin, and carboxylase [1]. Thiazole derivatives are widely ... I, R = H; II, R = 2,5-(MeO)2; III, R = Cl.